Watch a video that answers this question here.

The Short Answer: 

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

If people only occasionally used tobacco in their homes, they may be able to clean and remove much of the thirdhand smoke. If people frequently use tobacco in their home and it is heavily polluted with thirdhand smoke, it is probably impossible to remove the residue without major and expensive renovations to your home. This is because tobacco smoke chemicals can get deep into walls, floors, furniture, and upholstery.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

Removing thirdhand smoke from your home includes three approaches: cleaning washable household objects, cleaning unwashable items, and cleaning your home’s structure. 

Cleaning Washable Household Objects: Removing thirdhand smoke residue from household objects, like dishes, toys, clothes, and blankets, can be straightforward.

• Clean clothes, toys, and bedding in a washing machine. Depending on how polluted the fabrics are, you may need to wash them multiple times.
• Clean kitchenware and washable toys in a dishwasher. Depending on how polluted the objects are, you may need to wash them multiple times.
• Use diluted vinegar or basic cleaning solutions, such as Simple Green, to wash other objects and surfaces.

Cleaning Unwashable Items: Cleaning wall-to-wall carpets, furniture, upholstery, mattresses, books, and other personal belongings is typically not possible.

• Fabric-based items, such as carpets, furniture, upholstery, and mattresses, that cannot be completely submerged in water and scrubbed with soap will continue to retain thirdhand smoke reservoirs that readmit toxic pollutions.
• Items that cannot get wet, such as books and magazines, will continue to retain thirdhand smoke reservoirs that readmit toxic pollutions.
• These objects need to be replaced.  Even professional deep cleaning methods often fail to remove tobacco smoke residue that has penetrated into upholstery or into carpet padding.

Cleaning Structural Surfaces: Removing thirdhand smoke from structural elements, such as walls, floors, ceilings, doors, cabinets, HVAC units, airducts, and wall insultation is difficult and expensive, especially if there is a lot of thirdhand smoke in the home.

• If you hire a professional (e.g., painters, remediation experts), they typically use Trisodium Phosphate (TSP) to clean surfaces around the home. TSP is a hazardous chemical, and it requires specialized tools and personal protective equipment. TSP cannot remove thirdhand smoke residue embedded in porous materials like wood panels, particle board, and drywall.
• Alcohol-based primers and paint may trap thirdhand smoke residue on a wall. It may remove the tobacco odor (at least temporarily), but it does not remove thirdhand smoke chemicals. 
• Ozone generators remove tobacco odors from the air by changing odorant into odorless compounds. Ozone generators create new chemicals and do not remove chemicals embedded in materials. 
• Masking tobacco odors with fragrances also does not remove the chemicals.  It simply covers up unpleasant smells.
• In homes where smoking has taken place over many months or years, thirdhand smoke chemicals can soak into surfaces and become embedded in walls, flooring, carpets, and HVAC systems. Once the chemicals are embedded, cleaning the surface is not enough– the residue will resurface and re-emit back into the air. You must remove all of the thirdhand smoke, even what has soaked into surfaces in your home. 
• If thirdhand smoke is embedded in building materials, the only way to guarantee the residue is gone is to completely remodel by removing and replacing all walls, flooring, air ducts, etc.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: January 2025

Sources:

Ask This Old House. Understanding Thirdhand Smoke. Home Safety Videos. Retrieved from: https://www.thisoldhouse.com/home-safety/21249597/understanding-thirdhand-smoke

Bahl V, Jacob P, 3rd, Havel C, et al. Thirdhand cigarette smoke: Factors affecting exposure and remediation. PLOS One. 2014 Oct 6;9(10):e108258. doi: 10.1371/journal.pone.0108258. PubMed PMID: 25286392; PMCID: 4186756.

Matt GE, Quintana PJE, Hoh E, et al. Remediating thirdhand smoke pollution in multiunit housing: Temporary reductions and the challenges of persistent reservoirs. Nicotine & Tobacco Research 2021 Jan 22;23(2):364-72. Epub 2020/08/18. doi: 10.1093/ntr/ntaa151. PubMed PMID: 32803265; PMCID: PMC7822102.

Matt GE, Hoh E, Quintana PJE, et al. Cotton pillows: A novel field method for assessment of thirdhand smoke pollution. Environmental Research. 2019;168:206-10. Epub 2018/10/15. doi: 10.1016/j.envres.2018.09.025. PubMed PMID: 30317105.

Matt GE, Quintana PJ, Zakarian JM, et al. When smokers move out and non-smokers move in: residential thirdhand smoke pollution and exposure. Tobacco Control. 2010 Oct 11;20(1):e1. doi: 10.1136/tc.2010.037382. Epub 2016/05/13 PubMed PMID: 21037269; PMCID: 3666918.

Sleiman M, Destaillats H, Smith JD, Liu C-L, Ahmed M, Wilson KR, et al. Secondary organic aerosol formation from ozone-initiated reactions with nicotine and secondhand tobacco smoke. Atmospheric Environment. 2010;44(34):4191-8. doi: 10.1016/j.atmosenv.2010.07.023.

Tang X, Gambier C, López-Gálvez N, Padilla S, Rapp VH, Russell ML, et al. Remediation of Thirdhand Tobacco Smoke with Ozone: Probing Deep Reservoirs in Carpets. Environmental Science & Technoogy. 2023 Jun 27;57(27):9943-54. doi: 10.1021/acs.est.3c01628. PubMed PMID: 37366549.

Yang L, You B, Zhou W, et al. Rapid evolution of indoor primary and secondary organic aerosols from human activities. Building and Environment. 2024 Aug 1;261. doi: 10.1016/j.buildenv.2024.111736

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

Thirdhand smoke sticks to: 

Indoor Surfaces, such as:

• Walls
• Carpets
• Windows
• Doors

Household Objects, such as:

• Furniture
• Toys
• Books
• Dishes
• Bedding
• Curtains

People, including:

• Hair
• Skin
• Clothing

Thirdhand smoke can off-gas from these materials, and we can sometimes smell it as stale tobacco. The chemicals in thirdhand smoke can be spread by moving polluted objects from one place to another. 

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

After tobacco smoke disappears, thirdhand smoke stays on surfaces, in dust, and on objects. Thirdhand smoke soaks into materials and sticks to most indoor surfaces. This includes walls, carpets, windows, and doors. It can also stick to household objects, such as furniture, books, toys, dishes, silverware, curtains, blankets, and pillows. It can seep into drywall, insulation, furniture, books, and toys. It can stick to skin, hair, and clothing, too. People can carry thirdhand smoke from one place to another if they move polluted objects. 

In an environment where someone smokes tobacco for years, thirdhand smoke contaminates every surface and object. This includes hidden surfaces, such as under tables, inside closets and drawers, in the spongy padding material underneath the carpet, and in the home’s insulation. Some surfaces, such as drywall, carpets, and pillows, act like sponges soaking up water and store toxic thirdhand smoke chemicals. Just like water evaporating from a wet sponge, these chemicals can be released back into the air, leading to exposure long after someone smokes. People can move thirdhand smoke chemicals from place to place, such as when someone moves furniture from a smoking home into a smokefree home or when someone enters a smokefree indoor space after a smoking break.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: January 2025

Sources:

Matt GE, Hoh E, Quintana PJE, et al. Cotton pillows: A novel field method for assessment of thirdhand smoke pollution. Environmental Research. 2019 Jan;168:206-210. doi: 10.1016/j.envres.2018.09.025. Epub 2018 Sep 22. PMID: 30317105; PMCID: PMC6800039.

Matt, GE, Quintana, PJ, Hovell, MF, et al. Residual tobacco smoke pollution in used cars for sale: air, dust, and surfaces. Nicotine & Tobacco Research. 2008 Sep. 1;10(9), 1467-1475. doi:10.1080/14622200802279898.

Matt GE, Quintana PJE, Zakarian JM, et al. When smokers quit: exposure to nicotine and carcinogens persists from thirdhand smoke pollution. Tobacco Control. 2016 Sep. 21;26(5):548-556. doi: 10.1136/tobaccocontrol-2016-053119.

Merianos AL, Matt GE, Stone TM, et al. Contamination of surfaces in children’s homes with nicotine and the potent carcinogenic tobacco-specific nitrosamine NNK. Journal of Exposure Science & Environmental Epidemiology. 2023 Dec 16;34:727–734. doi: 10.1038/s41370-023-00629-8. Epub ahead of print. PMID: 38104233.

Northrup TF, Stotts AL, Suchting R, et al. Thirdhand Smoke Contamination and Infant Nicotine Exposure in a Neonatal Intensive Care Unit: An Observational Study. Nicotine & Tobacco Research. 2021 Aug 31;23(2);373–382. doi: 10.1093/ntr/ntaa167

Quintana PJE, Lopez-Galvez N, Matt GE, et al. Cotton pillow samplers for assessment of thirdhand smoke in homes of smokers and nonsmokers with children. Journal of Environmental Exposure Assessment. 2022 Nov 9;2(4):23. doi: 10.20517/jeea.2023.28.

Schick SF, Farraro KF, Perrino C, et al. Thirdhand cigarette smoke in an experimental chamber: evidence of surface deposition of nicotine, nitrosamines and polycyclic aromatic hydrocarbons and de novo formation of NNK. Tobacco Control. 2013 May 28;23(2):152-9. doi: 10.1136/tobaccocontrol-2012-050915. Epub 2016 May 13. PMID: 23716171.

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

If you smell stale tobacco smoke, thirdhand smoke is in the air. What you smell are the toxic chemicals that are released into the air from nearby contaminated sources, such as carpets, walls, and furniture. As soon as your nose picks up the odor, the polluted air gets into your lungs. From there, the toxic chemicals get into your blood and into every part of your body.

However, thirdhand smoke can still be present even if you don’t smell stale tobacco smoke. There may be too few chemicals in the air for you to detect, or the chemicals may be entirely odorless. 

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

Have you ever walked into a room and smelled the scent of stale tobacco smoke? Or maybe smelled it as someone walked by? The smell of stale cigarette smoke–even when no one is smoking– means that thirdhand smoke pollutants have been released into the air from the surfaces where they accumulated, such as carpets, walls, and furniture. As you breathe in, odor receptors in your nose recognize the chemicals in thirdhand smoke and trigger a signal in your brain that allows you to notice stale tobacco smoke while simultaneously bringing thirdhand smoke pollutants into your body.  

Thirdhand smoke pollutants contain chemicals that can harm many of your organs (including the nose, throat, lungs, and liver), damage how your cells normally function, damage your DNA, and cause cancer. Recent studies have found similar impacts from thirdhand aerosols from e-cigarettes.

Even when you cannot smell tobacco smoke, thirdhand smoke can still be present. Your sense of smell is a good warning system, but you can only smell an odor when the amount of a chemical is above the level that your nose can detect. In addition, some of the chemicals in thirdhand smoke are odorless; you cannot smell them no matter how much are present. 

So, while the smell of stale tobacco smoke can be a good indicator of thirdhand smoke, you can still be exposed to these harmful chemicals even if you cannot detect them.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: January 2025

Sources:

Hang B, Wang P, Zhao Y, et al. Adverse health effects of thirdhand smoke: From cell to animal models. International Journal of Molecular Sciences. 2017;18(5):942. doi: 10.3390/ijms18050932 

Martins-Green M, Adhami N, Frankos M, et al. Cigarette smoke toxins deposited on surfaces: Implications for human health. PLOS One. 2014;9(1). doi: 10.1371/journal.pone.0086391

Matt GE, Quintana PJE, Zakarian JM, et al. When smokers quit: Exposure to nicotine and carcinogens persists from thirdhand smoke pollution. Tobacco Control. 2016;26(5):548-556. doi: 10.1136/tobaccocontrol-2016-053119

Matt GE, Quintana PJ, Zakarian JM, et al. When smokers move out and non-smokers move in: Residential thirdhand smoke pollution and exposure. Tobacco Control. 2011;20(1). Epub 2010/10/30. doi: 10.1136/tc.2010.037382

Pozuelos G, Kagda M, Schick Set al. Acute exposure to thirdhand smoke leads to rapid changes in the human nasal epithelial transcriptome. JAMA Network Open. 2019;2(6) doi: 10.1001/jamanetworkopen.2019.6362

Thorpe AE, Donovan C, Kim RY, et al. Third-hand exposure to e-cigarette vapour induces pulmonary effects in mice. Toxics. 2023;11(9):749. doi: 10.3390/toxics11090749

Watch a video that answers this question here.

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

From tiny cells to entire organ systems, thirdhand smoke affects both people and pets. We know about the health risks of thirdhand smoke from four major types of research:

• Chemistry studies show that thirdhand smoke contains more than 25 chemicals known to cause cancer, affect a person’s ability to have children, or cause birth defects.
• Laboratory studies of lung, skin, liver, blood, and reproductive cells have shown that thirdhand smoke can impair cells’ ability to function and repair themselves.
• Animal studies have shown many health effects from thirdhand smoke exposure, including slow wound healing, increased “bad” cholesterol, liver function, and lung inflammation. 
• Studies with healthy human volunteers have shown thirdhand smoke exposure damages human cells and increases respiratory illnesses in children, including pulmonary illness, viral/other infectious illness, and bacterial infections.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

Thirdhand smoke impacts the health of people and animals at multiple levels. It can harm genetic material, affect how individual cells function, interfere with the body’s ability to fend off infections, and impair entire organ systems in the human body. Thirdhand smoke can worsen pre-existing conditions. 

Scientific evidence about the health effects of thirdhand smoke exposure comes from four major types of studies.

1) Health effects of chemicals found in thirdhand smoke

Thirdhand smoke contains some of the same toxic chemicals as first- and secondhand smoke, including nicotine, tobacco-specific nitrosamines, polycyclic aromatic hydrocarbons, heavy metals, and ultrafine particles. Exposure to these chemicals is known to harm human health. Chemical studies show that thirdhand smoke contains at least 25 chemicals known to cause cancer, affect a person’s ability to have children, or cause birth defects. Due to these health effects, California law lists these toxic chemicals under Proposition 65, which requires the state to maintain and update a list of chemicals known to cause cancer or reproductive toxicity. Additional harmful chemicals form when thirdhand smoke on surfaces and in dust comes in contact with other chemicals, such as ozone, in an indoor environment. 

2) Health effects of thirdhand smoke exposure on human cells 

Studies of human cells show that exposure to thirdhand smoke can directly damage DNA, the genetic material found in nearly every cell that contains the instructions our cells need to develop, function, grow, and reproduce. Thirdhand smoke causes oxidative stress in human cells, interfering with their normal functioning and repair mechanisms. Thirdhand smoke chemicals impair our cells’ ability to regenerate and repair themselves.  Thirdhand smoke can harm various cell types in the human body, including lung, skin, liver, blood, and reproductive cells.

3) Health effects of thirdhand smoke exposure on animals 

Decades of examining the health effects of thirdhand smoke exposure on animals has clearly established that thirdhand smoke is dangerous to health. In 1939, Dr. A. H. Roffo published one of the first animal studies on thirdhand smoke. He showed that rabbits developed skin cancer when tobacco smoke residue (condensate) was applied to their skin. In 1953, Dr. E. L. Wydner conducted a similar experiment in mice, showing the same outcomes. A more recent study by Dr. Martins-Green showed that mice exposed to thirdhand smoke through their bedding material have the following symptoms:

• slow wound healing
• inflammation in lungs
• elevated levels of fat in the liver
• high blood sugar levels
• increased blood clotting
• hyperactive behavior
• poor weight gain after birth
• elevated LDL (“bad”) cholesterol and low HDL (“good”) cholesterol levels

4) Health effects of thirdhand smoke on humans

Researchers have found that people living in or visiting places where people have smoked in the past are exposed to the toxic components of thirdhand smoke. Researchers determined this by measuring thirdhand smoke biomarkers in people’s urine, blood, or saliva.  They even found thirdhand smoke toxicants in newborns, infants, children, and nonsmoking adults living in thirdhand smoke-polluted environments.

Researchers at the University of California, San Francisco, studied the effects of thirdhand smoke exposure in human volunteers who do not smoke. They found that thirdhand smoke damaged the participants’ lung cells after only three hours of exposure.

Researchers from Cincinnati Children’s Hospital and San Diego State University found that children exposed to thirdhand smoke were more likely to be diagnosed with pulmonary illness, viral/other infectious illness, and bacterial infection.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: January 2025

Sources:

Roffo, AH. (1939) Krebserzeugendes Benzpyren, gewonnen aus Tabakteer.
Journal of Cancer Research and Clinical Oncology. 49, 588−597

Hang B, Wang P, Zhao Y, et al. Adverse health effects of thirdhand smoke: From cell to animal models. International Journal of Molecular Sciences. 2017;18(5). pii: E932. doi: 10.3390/ijms18050932

Jacob P 3rd, Benowitz NL, Destaillats H, et al. Thirdhand Smoke: New Evidence, Challenges, and Future Directions. Chemical Research in Toxicology. 2017;30(1):270-294. doi: 10.1021/acs.chemrestox.6b00343. 

Martins-Green M, Adhami N, Frankos M, et al. Cigarette smoke toxins deposited on surfaces: Implications for human health. PLoS One. 2014:9:1:e86391. doi: 10.1371/journal.pone.0086391

Mahabee-Gittens EM, Merianos AL, Jandarov RA, et al. Differential associations of hand nicotine and urinary cotinine with children’s exposure to tobacco smoke and clinical outcomes. Environmental Research. 2021;202:111722. doi: 10.1016/j.envres.2021.111722 . Epub 2021 Jul 21. PMID: 34297932; PMCID: PMC8578289

Matt GE, Greiner L, Record RA, et al. Policy-relevant differences between secondhand and thirdhand smoke: strengthening protections from involuntary exposure to tobacco smoke pollutants. Tobacco Control. 2023;33:798-806. doi: 10.1136/tc-2023-057971

Pozuelos G, Kagda M, Schick S, et al. Acute exposure to thirdhand smoke leads to rapid changes in the human nasal epithelial transcriptome. JAMA Network Open. 2019:2(6):e196362. doi: 10.1001/jamanetworkopen.2019.6362

Pratt K, Hilty A, Jacob P, et al. Respiratory Exposure to Thirdhand Cigarette Smoke Increases Concentrations of Urinary Metabolites of Nicotine. Nicotine and Tobacco Research. 2023;25(8):1424–30. doi: 10.1093/ntr/ntad002 

Sakamaki-Ching S, Schick S, Grigorean G, et al. Dermal thirdhand smoke exposure induces oxidative damage, initiates skin inflammatory markers, and adversely alters the human plasma proteome. eBioMedicine. 2022;84:104256. doi: 10.1038/s41598-021-92702-1

Tang X, Benowitz N, Gundel L, et al. Thirdhand Exposures to Tobacco-Specific Nitrosamines through Inhalation, Dust Ingestion, Dermal Uptake, and Epidermal Chemistry. Environmental Science & Technology. 2022;56(17):12506-16. doi: 10.1021/acs.est.2c02559.

Thorpe AE, Donovan C, Kim RY, et al. Third-Hand Exposure to E-Cigarette Vapour Induces Pulmonary Effects in Mice. Toxics. 2023;11(9):749. doi: 10.3390/toxics11090749 

Wynder EL, Graham EA, Croninger AB. Experimental production of carcinoma with cigarette tar. Cancer Research. 1953;13, 855-64

Yang H, Wang X, Wang P, He L, Schick SF, Jacob P, et al. Thirdhand tobacco smoke exposure increases the genetic background-dependent risk of pan-tumor development in Collaborative Cross mice. Environment International. 2023;174:107876. doi: 10.1016/j.envint.2023.107876 

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body through your lungs, skin, and mouth. Getting rid of it is really hard and can cost a lot of money.

Thirdhand smoke can stay on surfaces for years after the people who smoked stopped smoking or moved out. Because it can stay for years, researchers have found high levels of thirdhand smoke in apartments even when current residents do not smoke or allow smoking in their homes. In some of these homes, the levels of thirdhand smoke were so high that they were similar to levels in homes where people actively smoke indoors.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

In homes where tobacco has been smoked regularly over many years, thirdhand smoke residue is likely to be embedded in materials throughout the home. These pollution reservoirs can be very persistent. For instance, studies at the Thirdhand Smoke Resource Center have found high levels of thirdhand smoke on surfaces more than 5 years after the last known cigarette was smoked.

In one case, after a person who had smoked in the home moved out, the home was cleaned and remained empty for months. Still, thirdhand smoke levels on household surfaces were similar to those found in the homes of people who actively smoke. 

In a second case, a person with a lifelong one-pack-per-day habit successfully quit. Over five years later, thirdhand smoke levels on their household furniture were similar to levels commonly found in the homes of people who actively smoke.

Toxic thirdhand smoke residue is widespread and persistent. One study measured thirdhand smoke on surfaces in 220 apartments in San Diego. The researchers found thirdhand smoke in every apartment, even though most (88%) of the residents did not use any tobacco products. This is likely because previous residents smoked in the units or neighbors smoked in nearby units, and thirdhand smoke can stick around for years.  

Altogether, these examples and studies show that toxic thirdhand smoke residue can persist for years after the smoking stops.

Although it can be challenging and expensive to remove existing thirdhand smoke pollution, there are steps you can take. To prevent the build-up of thirdhand smoke in your home, do not allow anyone to smoke in or around you, your home, or your vehicle.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: February 2025

Sources:

Matt GE, Quintana PJE, Hoh E, et al. Persistent tobacco smoke residue in multiunit housing: Legacy of permissive indoor smoking policies and challenges in the implementation of smoking bans. Preventive Medicine Reports. 2020;18:101088. doi: 10.1016/j.pmedr.2020.101088 

Matt GE, Quintana PJE, Hovell M, et al. Residual tobacco smoke pollution in used cars for sale: Air, dust, and surfaces, Nicotine & Tobacco Research. 2008:10(9);14671475. doi:  10.1080/14622200802279898

Matt GE, Quintana PJE, Zakarian JM, et al. When smokers move out and non-smokers move in: Residential thirdhand smoke pollution and exposure, Tobacco Control. 2011;20:el. doi: 10.1136/tc.2010.037382

Matt GE, Quintana PJE, Zakarian JM, et al. When smokers quit: Exposure to nicotine and carcinogens persists from thirdhand smoke pollution. Tobacco Control., 2017;26:548-556. doi: 10.1136/tobaccocontrol-2016-053119

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body through your lungs, skin, and mouth. Getting rid of it is really hard and can cost a lot of money.

Young children are at the greatest risk of thirdhand smoke exposure. Here are some ways to keep thirdhand smoke out of their homes: 

• Make sure all your child’s indoor environments are 100% smokefree by not letting anyone use tobacco products in your home.
• If your child spends time with someone who smokes, have them wash their hands and face and change their clothes before seeing your child.
• If your child comes into contact with second- or thirdhand smoke, they should shower and change their clothes as soon as possible.
• Avoid thirdhand smoke when moving to a new home — before signing any paperwork — by asking if anyone has ever smoked in it.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

Babies and young children are at the greatest risk of exposure to thirdhand smoke. The best way to prevent exposure to thirdhand smoke is to ensure that your child’s home is 100% smokefree.

That means no smoking or vaping tobacco, e-cigarettes, or cannabis at any time inside your home or anywhere else your child spends time. This includes homes of friends and family, hotels, restaurants, entertainment venues, and childcare.

Here are additional steps you can take to keep thirdhand smoke out of your child’s environment.

In your home: 

• Remember that smoke can drift into your home, so do not allow anyone to smoke outside near doors, windows, or ventilation systems.
• Before renting an apartment or buying a new home, ask questions about previous residents’ use of tobacco, e-cigarettes, and cannabis. 
• Before bringing something used into your home, such as furniture or clothing, ask about tobacco, e-cigarette, and marijuana use by previous owners. If you can’t find out, factor that into your decision.
• Before someone who smokes visits your home, explain that when people smoke, thirdhand smoke residue sticks to their clothes, hands, face, body, and hair. Then, ask them to wash their hands, shower, and change into clean clothes before spending time in your home or with your child.  

In someone else’s home:

• Do your best to ensure that all adults who spend time with your child are 100% smokefree, especially childcare workers. 
• If your child spends time with someone who smokes, have them wash their hands and face and change their clothes before seeing your child.
• If you cannot avoid your child spending time somewhere that may contain thirdhand smoke, when your child comes home, have them shower and change into clean clothes.

If you believe that a home is polluted with thirdhand smoke:

It can be very difficult to remove thirdhand smoke from indoor environments, especially if the smoking took place for a long period of time. Depending on the size of the reservoir of pollutants, you may need a complete renovation. 

• You may be able to reduce thirdhand smoke in your home by (1) opening windows to air out rooms each week, (2) regularly wiping surfaces with a diluted white vinegar solution, (3) frequent dusting, and (4) daily vacuuming with a HEPA filter.
• If you have washable items that came from a home where someone smoked, such as clothes, toys, or blankets, thoroughly wash them or consider discarding them. For fabrics, we recommend three rounds of washing and drying to ensure that the toxic pollutants have been completely removed.
• Remember that it is nearly impossible to remove thirdhand smoke from walls, carpets, HVAC systems, and other large housing structures. If your home is polluted with thirdhand smoke, you will likely have to renovate and replace these.
• When moving into a new home, always ask if previous residents smoked and about the building’s smoking policies. If possible, choose a new home that has not been smoked in and a property that has a strict indoor smoking ban.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: February 2025

Sources:

Aquilina NJ, Jacob P, Benowitz NL, et al. Secondhand smoke exposure in school children in Malta assessed through urinary biomarkers. Environmental Research. 2022;204:112405. doi: 10.1016/j.envres.2021.112405

Jacob III P, Benowitz NL, Destaillats H, et al. Thirdhand smoke: New evidence, challenges, and future directions. Chemical Research in Toxicology. 2017;30(1):270-94. doi: 10.1021/acs.chemrestox.6b00343 

Jenssen BP, Walley SC, Boykan R, et al. Protecting children and adolescents from tobacco and nicotine. Pediatrics. 2023;151(5):e2023061806. doi: 10.1542/peds.2023-061806

Kassem NO, Daffa RM, Liles S, et al. Children’s exposure to secondhand and thirdhand smoke carcinogens and toxicants in homes of hookah smokers. Nicotine & Tobacco Research. 2014;16(7):961-75. doi: 10.1093/ntr/ntu016

Kelley ST, Liu W, Quintana PJE, et al. Altered microbiomes in thirdhand smoke-exposed children and their home environments. Pediatric Research. 2021;90:1153-1160. doi: 10.1038/s41390-021-01400-1

Mahabee-Gittens EM, Merianos AL, Hoh E, et al. Nicotine on children’s hands: Limited protection of smoking bans and initial clinical findings. Tobacco Use Insights. 2019;12:1-6. doi: 10.1177/1179173×18823493 

Mahabee-Gittens EM, Merianos AL, Jandarov RA, et al. Differential associations of hand nicotine and urinary cotinine with children’s exposure to tobacco smoke and clinical outcomes. Environmental Research. 2021;202:111722. doi: 10.1016/j.envres.2021.111722

Mahabee-Gittens EM, Merianos AL, Stone L, et al. Hand nicotine as an independent marker of thirdhand smoke pollution in children’s environments. Science of The Total Environment. 2022;849:157914. doi: 10.1016/j.scitotenv.2022.157914 

Mahabee-Gittens EM, Quintana PJE, Hoh E, et al. Collecting hand wipe samples to assess thirdhand smoke exposure. Frontiers Public Health. 2021;9:770505. doi:10.3389/fpubh.2021.770505

Matt GE, Quintana PJ, Hovell MF, et al. Households contaminated by environmental tobacco smoke: sources of infant exposures. Tobacco Control. 2004;13(1):29-37. doi: 10.1136/tc.2003.003889 

Northrup TF, Matt GE, Hovell MF, et al. Thirdhand smoke in the homes of medically fragile children: Assessing the impact of indoor smoking levels and smoking bans. Nicotine & Tobacco Research. 2016;18(5):1290-8. doi: 10.1093/ntr/ntv174

Quintana PJE, Lopez-Galvez N, Matt GE, et al. Cotton pillow samplers for assessment of thirdhand smoke in homes of smokers and nonsmokers with children. Journal of Environmental Exposure Assessment. 2023;2(4):23. doi: 10.20517/jeea.2023.28

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

Young children are at the greatest risk of thirdhand smoke exposure, and they need to be protected from exposure in all indoor environments – including in cars. Here are some ways to protect your child from thirdhand smoke exposure in cars.

• Don’t let anyone smoke or vape in your car.
• If your child rides with someone who smokes or vapes, be sure they do not smoke or vape when your child is in the car. Ask them to put the air conditioning in “outside air mode” to help bring fresh air into the car when your child rides with them. Wash your child’s car seat after, and don’t leave it in the car between rides.
• When buying a used car, ask if anyone has ever smoked in it.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

Babies and young children are at the greatest risk of exposure to thirdhand smoke. They can be exposed to thirdhand smoke in any indoor environment – including inside cars. Cars are full of materials that collect tobacco smoke pollutants, such as the upholstery, ceiling liner, and floor mats. While and after people smoke in a car, the polluted air is trapped inside, where children often spend significant amounts of time. Here are some steps you can take to keep your child safe from thirdhand smoke in cars.

Make sure your child travels in 100% smokefree cars. 

• Don’t allow any smoking or vaping in your car at any time, and don’t let your child ride with anyone who allows smoking or vaping in their car. 
• If you are buying a used car, be sure to ask about smoking by previous owners. 
• Unfortunately, it is virtually impossible to remove thirdhand smoke once it is embedded in a car. Even aggressive cleaning will not remove the toxic chemicals hidden in upholstery or the ventilation system. 

If you cannot avoid your child riding in a car that may contain thirdhand smoke, there are a few steps you can take to reduce your child’s exposure:

• When your child is in a car polluted with thirdhand smoke, turn on the air-conditioning using the “outside air mode” or open the windows. Make sure you do not simply recirculate the air in your car, which is typically the default setting in a car. By bringing outside air into the car using air-conditioning, you will temporarily reduce the concentration of thirdhand smoke pollutants in the air of the car.
• Before you put a car seat in the car, put a clean towel under the car seat. The towel will act as a physical barrier between the car’s upholstery, which contains thirdhand smoke pollutants, and the clean car seat.
• Do not leave a car seat in the car. Put your child’s car seat in the car only when your child will be using it. The less time the car seat is in the car, the less time it will be exposed to toxic thirdhand smoke.
• When you are finished using the car seat, remove it and the towel. Wipe the car seat with a solution of diluted vinegar and water and throw the towel into the laundry.
• As much as possible, limit the amount of time your child is in the car.
• Because children can absorb thirdhand smoke through their skin, it is a good idea to wash your child’s hands and face after the car ride.

The best ways to protect your child from thirdhand smoke exposure in a car is to (1) never ride in cars that have been smoked in, (2) never let anyone smoke in your car, and (3) always ask for a non-smoking rental car. If you smell tobacco odor in the rental car, ask for another.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: March 2025

Sources:

Fortmann AL, Romero RA, Sklar M, et al. Residual tobacco smoke in used cars: Futile efforts and persistent pollutants. Nicotine & Tobacco Research. 2010;12(10):1029-1036. doi: 10.1093/ntr%2Fntq144 

Matt GE, Fortmann AL, Quintana PJ, et al. Towards smoke-free rental cars: An evaluation of voluntary smoking restrictions in California. Tobacco Control. 2013;22(3):201-7. doi: 10.1136/tobaccocontrol-2011-050231 

Matt GE, Quintana PJ, Hovell MF, et al. Residual tobacco smoke pollution in used cars for sale: Air, dust, and surfaces. Nicotine & Tobacco Research. 2008;10(9):1467-1475. doi: 10.1080/14622200802279898

Mahabee-Gittens EM, Merianos AL, Stone L, et al. Hand nicotine as an independent marker of thirdhand smoke pollution in children’s environments. Science of The Total Environment. 2022;849:157914. doi: 10.1016/j.scitotenv.2022.157914

Matt GE, Fortmann AL, Quintana PJ, et al. Towards smoke-free rental cars: An evaluation of voluntary smoking restrictions in California. Tobacco Control. 2013;22(3):201-207. doi: 10.1136/tobaccocontrol-2011-050231

The Short Answer

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

Yes, after smoking, people bring thirdhand smoke with them when they enter a home, car, or other enclosed spaces, such as a movie theater, hospital, or public transportation.

When someone smokes, thirdhand smoke sticks to their clothes, skin, hair, and mouth. The thirdhand smoke chemicals can transfer from the person to surfaces they touch. The chemicals can be released back into the air, producing a smell of old or stale tobacco smoke.  

To avoid people carrying thirdhand smoke into your home or car, ask those who smoked to change clothes, wash their hands and face, and shower before entering your home or car.

The Long Answer

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. Thirdhand smoke chemical residue can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

When someone who smokes outside enters a home, car, or other enclosed space, such as a movie theater, hospital, or public transportation, they bring thirdhand smoke with them. Often, they will smell like tobacco smoke, but even if they don’t, they still carry thirdhand smoke chemicals on their clothes, skin, hair, mouth, and breath. We smell tobacco smoke when the thirdhand smoke chemicals are released into the air, a process known as off-gassing. Some of these chemicals in the air are recognized by the odor receptors in our noses, and our brains tell us that this is the unpleasant smell of stale tobacco smoke.

Once this tobacco residue is brought inside, the effects are similar to when someone smokes a cigarette inside your car or home. The gases and particles in the tobacco residue on the hands, clothes, skin, and hair of the person who smoked can be transferred, stick to, and ultimately become embedded in materials and objects. In your home and workplace, these include carpets, walls, furniture, blankets, and toys. In your car, these include the seats, steering wheel, floor mats, and ceiling liner. The gases and particles can also be released into the air and accumulate in dust. As a result, people and pets may be exposed to toxic thirdhand smoke even though no one smoked inside your car or home.

The first step to avoiding exposure to thirdhand smoke is to tell family members and friends about thirdhand smoke and encourage them to avoid exposure. Ask friends and family who smoke to adopt these strategies to protect others: 

1. Always wash your hands and face very carefully after smoking to remove tobacco residue from your skin.
2. Wash clothes worn while smoking each day to avoid releasing toxic compounds into the air.
3. If possible, shower and change into clean clothes upon entering the home of someone who does not smoke.

Be sure to thank them for helping to protect you and your loved ones from toxic thirdhand smoke.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: July 2025

Sources:

Fortmann A L, Romero RA, Sklar RA, et al. Residual tobacco smoke in used cars: Futile efforts and persistent pollutants. Nicotine & Tobacco Residue. 2010;12(10):1029-36. doi: 10.1093/ntr/ntq144 

Licina D, Morrison GC, Bekö G, et al. Clothing-mediated exposures to chemicals and particles. Environmental Science & Technology. 2019;53(10):5559-5575. doi: 10.1021/acs.est.9b00272 

Lidón-Moyano C, Fu M, Pérez-Ortuño R, et al. Third-hand exposure at homes: Assessment using salivary cotinine. Environmental Research. 2021;196:110393. doi: 10.1016/j.envres.2020.110393

Matt GE, Romero R, Ma DS, et al. Tobacco use and asking prices of used cars: Prevalence, costs, and new opportunities for changing smoking behavior. Tobacco Induced Diseases. 2008;4(1):2. doi: 10.1186/1617-9625-4-2 

Matt GE, Quintana PJ, Hovell MF, et al. Residual tobacco smoke pollution in used cars for sale: Air, dust, and surfaces. Nicotine & Tobacco Research. 2008;10(9):1467-1475. doi: 10.1080/14622200802279898

Matt GE, Quintana PJ, Zakarian JM, Fortmann AL, Chatfield DA, Hoh E, Uribe AM, Hovell MF. When smokers move out and non-smokers move in: Residential thirdhand smoke pollution and exposure. Tobacco Control. 2011;20(1):e1. doi: 10.1136/tc.2010.037382

Northrup TF, Stotts AL, Suchting R, et al. Thirdhand smoke contamination and infant nicotine exposure in a neonatal intensive care unit: An observational study. Nicotine & Tobacco Research. 2021;23(2):373-382. doi: 10.1093/ntr/ntaa167 

Rosen LJ, Zucker DM, Gravely S, et al. Tobacco smoke exposure according to location of home smoking in Israel: Findings from the project zero exposure study. International Journal of Environmental Research and Public Health. 2023;20(4):3523. doi: 10.3390/ijerph20043523  

Sheu R, Stönner C, Ditto J, et al. Human transport of thirdhand tobacco smoke: A prominent source of hazardous air pollutants into indoor nonsmoking environments. Science Advances. 2020;6(10):eaay4109. doi: 10.1126/sciadv.aay4109 

Quintana PJE, Lopez-Galvez N, Matt GE, et al. Cotton pillow samplers for assessment of thirdhand smoke in homes of smokers and nonsmokers with children. Journal of Environmental Exposure Assessment. 2023;2(4):23. doi: 10.20517/jeea.2023.28 

Quintana PJ, Matt GE, Chatfield D, et al. Wipe sampling for nicotine as a marker of thirdhand tobacco smoke contamination on surfaces in homes, cars, and hotels. Nicotine & Tobacco Research. 2013;15(9):1555-63. doi: 10.1093/ntr/ntt014

Watch a video that answers this question here.

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

Infants and young children are the most likely to breathe in, swallow, or touch thirdhand smoke chemicals for three reasons:

1. They spend most of their time indoors, especially on the floor. This means they are nearer to carpets and dust contaminated with thirdhand smoke chemicals. 
2. They explore by putting things into their mouths. This means they can put toys, blankets, and other objects contaminated with thirdhand smoke chemicals into their mouths. 
3. Their bodies are developing. Young children breathe more frequently. This means that they have more chances to breathe in thirdhand smoke chemicals. Also, their skin is thinner than adults, so it does not create a barrier to keep the chemicals out.   

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

Infants and young children are the most likely to be exposed to thirdhand smoke for these three reasons:

1. Time Spent Indoors

Infants and young children spend more time on average indoors than adults. Human activity surveys have shown that infants spend 90% of their time indoors at home. If their home environments are polluted with thirdhand smoke, infants are at a higher risk of exposure.

2. Child Behavior

Infants and young children explore their environment with their hands and bodies. Before they can walk, they move around by crawling along the floor, where they can touch polluted objects and pick up polluted dust and particles along the way. Their small size lets them fit into tight spaces where dust and particles might collect. Through crawling and exploring their environment, their hands, mouths, hair, clothes, and toys can collect thirdhand smoke. 

As part of exploring their environment, children and infants put many objects into their mouths: their own hands, toys, blankets, their parents’ fingers, a car seat strap, and more. Just about anything they discover goes into their mouths, including everyday objects parents may use to distract a child, such as a cell phone, car keys, or TV remote. 

If their environment contains surfaces, objects, or dust contaminated with toxic thirdhand smoke, the chemicals can enter their bodies through touching, inhaling, or swallowing them. 

3. Growth and Development

The respiratory systems of infants and young children are developing, and they breathe more times each minute than adults do. This increased respiratory rate means that in relation to their size, they can breathe in more thirdhand smoke than adults can. Their other organ systems are immature and growing too—this includes their skin. The skin of an infant or child is thinner than the skin of adults, meaning that their skin creates less of a barrier to keep thirdhand smoke chemicals from being absorbed into their bodies. Their immune systems are also developing, making them more vulnerable to the effects of tobacco pollutants than adults. A weakened immune system makes it more difficult to fend off infections.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: March 2025

Sources:

Breunis LJ, Versteylen M, Radó MK, et al. Pediatric patients’ views regarding smoke-free hospital grounds compared to those of adults: A survey study. Tobacco Prevention & Cessation. 2022;8:7. doi: 10.18332/tpc/145311

Jenssen BP, Walley SC, Boykan R, et al. Protecting children and adolescents from tobacco and nicotine. Pediatrics. 2023;151(5):e2023061806. doi: 10.1542/peds.2023-061806

Kelley ST, Liu W, Quintana PJE, et al. Altered microbiomes in thirdhand smoke-exposed children and their home environments. Pediatric Research. 2021;90(6):1153-1160. doi: 10.1038/s41390-021-01400-1

Mahabee-Gittens EM, Merianos AL, Jandarov RA, et al. Differential associations of hand nicotine and urinary cotinine with children’s exposure to tobacco smoke and clinical outcomes. Environmental Research. 2021;202:111722. doi: 10.1016/j.envres.2021.111722

Mahabee-Gittens EM, Merianos AL, Matt GE. Preliminary evidence that high levels of nicotine on children’s hands may contribute to overall tobacco smoke exposure. Tobacco Control. 2018;27(2):217-219. doi: 10.1136/tobaccocontrol-2016-053602

Mahabee-Gittens EM, Merianos AL, Quintana PJE, et al. Nicotine on children’s hands: Limited protection of smoking bans and initial clinical findings. Tobacco Use Insights. 2019;12:1-6. doi: 10.1177/1179173X18823493

Mahabee-Gittens EM, Merianos AL, Stone L, et al. Hand nicotine as an independent marker of thirdhand smoke pollution in children’s environments. Science of The Total Environment. 2022;849;157914. doi: 10.1016/j.scitotenv.2022.157914

Matt GE, Quintana PJE, Hovell MF, et al. Households contaminated by environmental tobacco smoke: sources of infant exposures. Tobacco Control. 2004;13:29–37. doi: 10.1136/tc.2003.003889

Merianos AL, Jandarov RA, Gordon JS, et al. Healthcare resources attributable to child tobacco smoke exposure. PLOS ONE. 2021;16(2):e0247179. doi: 10.1371/journal.pone.0247179

Merianos AL, Mahabee-Gittens EM, Choi K. Tobacco smoke exposure and inadequate sleep among U.S. school-aged children. Sleep Medicine. 2021;86:99-105. doi: 10.1016/j.sleep.2021.08.012

Northrup TF, Khan AM, Jacob P, et al. Thirdhand smoke contamination in hospital settings: Assessing exposure risk for vulnerable pediatric patients. Tobacco Control. 2016;25:619-623. doi: 10.1136/tobaccocontrol-2015-052506

Parks J, McLean KE, McCandless L, et al. Assessing secondhand and thirdhand tobacco smoke exposure in Canadian infants using questionnaires, biomarkers, and machine learning. Journal of Exposure Science and Environmental Epidemiology. 2022;32:112–123. doi: 10.1038/s41370-021-00350-4

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

Smokefree properties protect people’s health by reducing their exposure to toxic second- and thirdhand smoke. Making rental properties smokefree will also save you money. Many people know the dangers of secondhand smoke and want to live somewhere smokefree. In addition, smokefree properties have less fire risk and smoking-related maintenance, such as having to do less deep cleaning of thirdhand smoke-polluted rooms between tenants. 

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

Smokefree rental properties are in high demand. Surveys show that most renters prefer 100% smokefree properties. 

Smokefree rental properties save lives and protect the health of tenants by:

• Eliminating current tenants’ exposure to secondhand smoke that drifts between apartments.
• Preventing future residents’ exposure to thirdhand smoke chemicals that have become embedded in rugs, walls, and other surfaces in units where previous tenants smoked.

Smokefree rental properties save money by:

• Reducing the risk of tobacco-related fires in apartments.
• Lowering fire and liability insurance premiums for the property.
• Avoiding the need for expensive smoking-related repairs when tenants move out.
• Reducing litter from tobacco waste, such as cigarette butts.
• Reducing complaints about unpleasant odors and unhealthy air because of smoke intrusion.

Save lives, save money. Make your property smokefree.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: March 2025

Sources:

Licht AS, King BA, Travers MJ, et al. Attitudes, experiences, and acceptance of smoke-free policies among US multiunit housing residents. American Journal of Public Health. 2012;102(10):1868-1871. doi: 10.2105/AJPH.2012.300717

Ong MK, Diamant AL, Zhou Q, et al. Estimates of smoking-related property costs in California multiunit housing. American Journal of Public Health. 2012;102(3):490-493. doi: 10.2105/AJPH.2011.300170 

Smokefree housing: Renter poll. American Lung Association. 2020. Retrieved from: https://center4tobaccopolicy.org/tobacco-policy/smokefree-multi-unit-housing/smokefree-housing-renter-poll/

Thorpe LE, Anastasiou E, Wyka K, et al. Evaluation of secondhand smoke exposure in New York City public housing after implementation of the 2018 Federal Smoke-Free Housing Policy. JAMA Network Open. 2020;3(11):e2024385. doi: 10.1001/jamanetworkopen.2020.24385

Toy P, Yount C, Meng Y, et al. Health at risk: Policies are needed to end cigarette, marijuana, and e-cigarette secondhand smoke in multi-unit housing in Los Angeles. UCLA Center for Health Policy Research. 2020. Retrieved from: https://healthpolicy.ucla.edu/our-work/publications/health-risk-policies-are-needed-end-cigarette-marijuana-and-e-cigarette-secondhand-smoke-multi-unit 

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

To avoid thirdhand smoke, your new apartment should be in a smokefree property. If the property formerly allowed smoking, then the unit should be thoroughly cleaned and renovated to remove any thirdhand smoke left by prior residents who smoked. 

Before you sign your next lease, ask: 

• Where is smoking allowed on the property? Be sure to ask about the units, balconies, porches, and common areas.  
• How are tenants informed about the smoking policy? 
  • What are the consequences if tenants break the policy? 
  • Are the consequences enforced?
• Have any previous residents smoked in the unit I want to rent?
  • If yes, how was the unit cleaned or renovated since they moved out? 

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

Before you sign the lease on an apartment, consider the following:

• The definition of smokefree differs for each apartment complex. Sometimes, smokefree means that smoking is prohibited in some areas, such as common areas, but allowed in others, such as personal patios or inside units. Other times smokefree means smoking is prohibited anywhere on the property.  
• Smokefree does not necessarily mean your new apartment is free of toxic thirdhand smoke residue. Thirdhand smoke can be left behind by a former resident, a neighbor who smoked before the complex implemented smokefree policies, or someone who simply ignored the smokefree policies after they were implemented.

Make sure you understand the smoking restrictions for the property you are interested in: 

• Ask the property manager where smoking is allowed on the property.
  • Hopefully, they will say, “Smoking or vaping is not allowed anywhere on the property. Residents must leave the property to smoke.”
  • Most likely, they will say, “We allow smoking and vaping in specific areas.”

Smoke travels easily through open windows, hallways, heating and cooling systems, and around pipes and electrical wiring. If people are allowed to smoke inside their apartment units, outside on their porches or balconies, or in common areas near buildings or stairwells, the smoke will likely find its way into your apartment.

If smoking is allowed anywhere on the property, ask where people are allowed to smoke: 

• Is smoking allowed inside apartment units?
• Is smoking allowed in private areas and outdoor areas, such as balconies or porches?
• Is smoking allowed in common areas, playgrounds, pool areas, or parking lots?
• Is smoking prohibited within 25 feet of the building’s doors and windows?
• Is there a designated smoking area? If so, is it more than 50 feet from any building?

In addition, you want to ask the property management the following: 

• How are tenants or visitors informed about the smoking policy? 
• What is the penalty for violating the smoking policy?
• Are there signs posted throughout the complex about the smoking policy, including the penalty for violating it?
• How do you handle tenants’ complaints about others smoking?

Once you are convinced that the smoking policies are enforced and that no smoking is tolerated on the premises, you still need to confirm that thirdhand smoke is not present in the unit you hope to rent. If previous residents smoked inside or outside of the unit, toxic thirdhand smoke residue can remain for years after they have moved out. 

To find out if thirdhand smoke may be present in the unit, ask the property manager:

• Did the people who lived in this apartment smoke?

If the answer is “yes”, you should investigate more by asking:

• How long did they live in the apartment?
• What kind of cleaning or renovation was done to the unit after they moved out?

We recommend that you request a unit that was not previously occupied by someone who smoked. The longer a tenant who smoked lived in the unit, the more time there would have been for toxic thirdhand smoke residue to build up. It is important to find out how property management prepares and cleans apartments for new tenants. 

It is unlikely that standard cleaning and applying a new coat of paint will remove thirdhand smoke, especially if the smoking was heavy and occurred for a long time. Renovation to remove thirdhand smoke may need to include the replacement of carpeting, cabinets, walls, ceilings, and ventilation systems.

We know it is challenging to find good housing. Many factors go into a final decision about where to live. Since there is no safe level of exposure to tobacco smoke, we suggest avoiding a unit where a former smoker lived. We also suggest avoiding properties that allow smoking anywhere on the property and where there are few consequences for violating smoking policies.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: March 2025

Sources: 

Chu AK, Kaufman P, Chaiton M. Prevalence of involuntary environmental cannabis and tobacco smoke exposure in multi-unit housing. International Journal of Environmental Research and Public Health. 2019;16(18):3332. doi: 10.3390/ijerph16183332

DeCarlo PF, Avery AM, Waring MS. Thirdhand smoke uptake to aerosol particles in the indoor environment. Science Advances. 2018;9:4(5):eaap8368. doi: 10.1126/sciadv.aap8368

Mahabee-Gittens EM, Merianos AL, Quintana PJE, et al. Nicotine on children’s hands: Limited protection of smoking bans and initial clinical findings. Tobacco Use Insights. 2019;12. doi: 10.1177/1179173X18823493

Matt GE, Quintana PJE, Hoh E, et al. Persistent tobacco smoke residue in multiunit housing: Legacy of permissive indoor smoking policies and challenges in the implementation of smoking bans. Preventive Medicine Reports. 2020;18:101088. doi: 10.1016/j.pmedr.2020.101088

Matt GE, Quintana PJE, Hoh E, et al. Remediating thirdhand smoke pollution in multiunit housing: Temporary reductions and the challenges of persistent reservoirs. Nicotine & Tobacco Research. 2021;23(2):364-372. doi: 10.1093/ntr/ntaa151

Matt GE, Quintana PJE, Zakarian JM, et al. When smokers move out and non-smokers move in: Residential thirdhand smoke pollution and exposure. Tobacco Control. 2011;20(1):e1. doi: 10.1136/tc.2010.037382

Toy P, Yount C, Meng Y, et al. Health at risk: Policies are needed to end cigarette, marijuana, and e-cigarette secondhand smoke in multi-unit housing in Los Angeles. UCLA Center for Health Policy Research. 2020. Retrieved from: https://healthpolicy.ucla.edu/our-work/publications/health-risk-policies-are-needed-end-cigarette-marijuana-and-e-cigarette-secondhand-smoke-multi-unit

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

Electronic cigarettes (also called e-cigarettes, vapes, or ENDS products) heat up a liquid that contains nicotine and other chemicals, becoming clouds of tiny aerosols. These clouds act like secondhand smoke, sticking to surfaces and household objects. They become thirdhand chemical residue from vape aerosols that exposes people to toxic chemicals. This residue includes carcinogens called TSNAs.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

Electronic cigarettes (also called e-cigarettes, vapes, or ENDS products) do not burn tobacco. Instead, e-cigarettes heat a fluid that contains nicotine, nicotine by-products, a chemical solvent, and flavor chemicals. This heated fluid creates a vapor made up of tiny droplets, called aerosols, that look like cigarette smoke. 

Aerosols from vapes act similarly to aerosols and gases from smoking cigarettes. They move through the air, can spread to other rooms, and collect in dust. They also stick to surfaces and household objects, creating thirdhand chemical residue and exposing people to the chemicals. This thirdhand chemical residue from vape aerosols can interact with other chemicals in the air to form new cancer-causing substances. They can also transfer from room to room, such as from a vape shop into a neighboring business. They can also be transported on people who vape into a smokefree and vapefree environment.

Researchers have found thirdhand chemical residue from vape aerosols on indoor surfaces days after vaping had stopped. In one study looking at thirdhand chemical residue from vape aerosols in vape shops, the researchers found nicotine as well as additional toxic nicotine-related chemicals on surfaces in the shops. They also found the chemicals to stick to paper, clothing, and glass after these materials sat in the vape shops for 14 days. Another study of JUUL e-cigarettes confirmed that exhaled vapor leaves toxic thirdhand chemical residue from vape aerosols on surfaces. A recent study also showed that vaping generates potent carcinogens known as TSNAs. Some TSNAs quickly formed during and right after vaping occurred. Over the following 36 hours, the amount of all TSNA’s grew. This suggests TSNAs formed from nicotine in thirdhand chemical residue from vape aerosols.

Children can inhale secondhand vape aerosols and pick up thirdhand chemical residue from vape aerosols on their hands. Like thirdhand smoke residue, children are the most vulnerable to the toxic chemicals in thirdhand chemical residue from vape aerosols.

To prevent the build-up of thirdhand chemical residue from vape aerosols in your home and car, do not allow anyone to vape in those spaces.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: March 2025

Sources: 

Goniewicz, M. L., & Lee, L. Electronic cigarettes are a source of thirdhand exposure to nicotine. Nicotine & Tobacco Research. 2015;17(2):256–258. doi: 10.1093/ntr/ntu152

Hua M, Luo W, Khachatoorian C, et al. Exposure, Retention, Exhalation, Symptoms, and Environmental Accumulation of Chemicals During JUUL Vaping. Chemical Research in Toxicology. 2023;36(3):492-507. doi: 10.1021/acs.chemrestox.2c00390

Khachatoorian C, Jacob III P, Benowitz NL, et al. Electronic cigarette chemicals transfer from a vape shop to a nearby business in a multiple-tenant retail building. Tobacco Control, 2019;28(5):519–525. doi: 10.1136/tobaccocontrol-2018-054316

Li D, Shi H, Xie Z, et al. Home smoking and vaping policies among US adults: Results from the Population Assessment of Tobacco and Health (Path) study, wave 3. Preventive Medicine. 2020;139:106215. doi: 10.1016/j.ypmed.2020.106215

Marcham CL, Floyd EL, Wood, BL, et al. E-cigarette nicotine deposition and persistence on glass and cotton surfaces. Journal of Occupational and Environmental Hygiene, 2019;16(5):349–354. doi: 10.1080/15459624.2019.1581366

Son Y, Giovenco DP, Delnevo C, et al. Indoor air quality and passive e-cigarette aerosol exposures in vape-shops. Nicotine & Tobacco Research. 2020;22(10):1772–1779. doi: 10.1093/ntr/ntaa094

Wang S, Bao L, Li T, et al. Potential health risk of human exposure to tobacco-specific nitrosamines in second-hand and third-hand smoke. Journal of Hazardous Materials. 2024;480. doi: 10.1016/j.jhazmat.2024.136446 

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

Scientists have created sensitive tests for research studies that detect thirdhand smoke chemicals in air, on surfaces, and in dust. Thirdhand smoke chemicals include nicotine, tobacco-specific nitrosamines, and lead. These chemicals can cause health effects, including cancer. Unfortunately, these sensitive tests are currently not available for sale to the public and remain available only to researchers in labs. 

Several commercial companies are selling tests to the public to measure thirdhand smoke chemicals. However, these tests are currently not sensitive enough to accurately measure thirdhand smoke residue, or they may not yet have been thoroughly investigated to trust the results. Importantly, they may create a false sense of security when they report, “not detected.” To better measure thirdhand smoke residue, commercial tests must be developed that are more sensitive and have been shown to give correct results.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

Tobacco smoke contains thousands of chemicals that can stick to surfaces, collect in dust, and interact with the environment. Some of the most studied chemicals are nicotine (an addictive compound in tobacco products that causes health effects), tobacco-specific nitrosamines (cancer-causing chemicals formed when tobacco burns), and nicotelline (a chemical found in tobacco smoke that remains as particulate matter), and lead.

Scientists have developed sensitive tests using these chemicals to identify thirdhand smoke chemicals in the air, house dust, and on surfaces of indoor environments, such as furniture, pillows, car interiors, and walls. Currently, these tests require expensive equipment and are limited to research laboratories.

Commercial tests are available to identify highly contaminated environments (e.g., homes of people who currently smoke).  However, they are not sufficiently sensitive to conclude that no thirdhand smoke is present in a home or that it does not exceed unavoidable background levels. 

For example, EMSL produces a test kit for nicotine on surfaces, but this test is only sensitive enough to detect very high levels of nicotine. A “no nicotine detected” result from this test kit may be inaccurate because only the most polluted surfaces would report positive for nicotine. The test’s lowest nicotine detection level (i.e., reporting limit) is about 15 times higher (15 µg/m2) than typically found in homes of people who do not smoke and have indoor smoking bans (1 µg/m2).

Similarly, Knowsmoke produces a test kit for the automobile and rental car industry. It measures nicotine in upholstery and carpeting. Initial findings suggest that it may be sufficiently sensitive, but basic validation results have not yet been published.

Finally, the Home Air Check measures nicotine in the air. Nicotine in the air is not specific to thirdhand smoke, and positive nicotine results could come from second- or thirdhand smoke. Its lowest detection level is 1 ng/liter (1 µg/m3). This detection limit is too high to test second- or thirdhand smoke sensitively.

For a thirdhand smoke test to accurately measure if a home is free of tobacco smoke pollutants, the test must be significantly more sensitive than what is currently commercially available. At the Thirdhand Smoke Resource Center, we are currently developing sensitive tests to detect thirdhand smoke and to compare levels to different environments (e.g., homes where no smoking is allowed, homes where smoking is allowed outdoors, and homes where smoking is allowed indoors). If you are in urgent need of a test, we recommend reaching out to us to determine if you qualify to participate in our pilot study: contact@thirdhandsmoke.org.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: March 2025

Sources:

Aquilina NJ, Havel CM, Cheung P, et al. Ubiquitous atmospheric contamination by tobacco smoke: Nicotine and a new marker for tobacco smoke-derived particulate matter, nicotelline. Environmental International. 2021;27. doi: 10.1016/j.envint.2021.106417

Nicotine Smoke Contamination Test Kit. EMSL Analytical, Inc. Retrieved: https://www.emsl.com/Page.aspx?ID=572  

Tobacco Smoke Check. Home Air Check. https://www.homeaircheck.com/product/tobacco-smoke-test/. 

Knowsmoke Test Kit. Knowsmoke. https://www.knowsmoke.com/product/knowsmoke-test-kit/

Matt GE, Quintana PJE, Hoh E, et al. A casino goes smoke free: A longitudinal study of secondhand and thirdhand smoke pollution and exposure. Tobacco Control. 2018;27(6):643-649. doi: 10.1136/tobaccocontrol-2017-054052

Matt GE, Quintana PJ, Zakarian JM, et al. When smokers move out and non-smokers move in: Residential thirdhand smoke pollution and exposure. Tobacco Control. 2011;20(1):e1. doi: 10.1136/tc.2010.037382

Quintana PJ, Matt GE, Chatfield D, et al. Wipe sampling for nicotine as a marker of thirdhand tobacco smoke contamination on surfaces in homes, cars, and hotels. Nicotine & Tobacco Research. 2013;15(9):1555-1563. doi: 10.1093/ntr%2Fntt014 

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

To improve your chances of getting a rental car 100% free of thirdhand chemical residue from smoking or vaping, take these steps:

1. Before renting your car, look for a company that does not allow smoking or vaping in any of their vehicles.
2. At the rental counter, remind them that you want a car that has not been smoked or vaped in. Asking for a low-mileage car can be beneficial in that there are fewer chances that a previous renter smoked or vaped in it.
3. Before driving away, check for odors, burn marks, stains, or other signs of smoking or vaping in the car. Ask for a different car if necessary.
4. When returning the car, thank the company for enforcing smokefree policies.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

When renting a car, a little bit of research and a few simple steps can increase the chances of getting a car 100% free of thirdhand chemical residue from smoking or vaping.

Before reserving your car:

1. Choose a rental car company with a no-smoking policy for all of their vehicles.
2. Read the no-smoking policy to make sure it includes vapes and electronic cigarettes.
3. Make sure the fine for violating the policy is severe enough to make someone think twice before smoking in the car.

At the rental counter:

1. Even if the company has a no-smoking policy, verbally confirm that you want a car that has not been smoked or vaped in.
2. Request a car that has a low mileage. The lower the mileage, the fewer previous renters and the fewer chances that a previous renter smoked or vaped in the car.
   

Before you drive out of the rental car lot:

1. Be sure there is some form of a “non-smoking” designation, such as a sticker on the car window or dashboard. Reminders reduce the chances that a previous renter smoked or vaped inside the car.
2. Look for evidence of tobacco use, such as a stale tobacco odor, burn marks, cloudy windows inside, and littered tobacco products.
3. If you feel that smoking or vaping might have occurred in the vehicle, request another one.
   

When you return the vehicle:

1. Reinforce the rental company’s good choices. Thank the management and staff for providing vehicles that have not been smoked or vaped in.
2. Post a positive review about your smokefree ride and share it on social media.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: March 2025

Sources:

Continente X, Henderson E, López-González L, et al. Exposure to secondhand and thirdhand smoke in private vehicles: Measurements in air and dust samples. Environmental Research. 2023;235:116681. doi: 10.1016/j.envres.2023.116681

Drehmer JE, Nabi-Burza E, Walters BH, et al. Parental smoking and e-cigarette use in homes and cars. Pediatrics. 2019;143(4). doi: 10.1542/peds.2018-3249

Matt GE, Fortmann AL, Quintana PJ, et al. Towards smoke-free rental cars: An evaluation of voluntary smoking restrictions in California. Tobacco Control. 2013;22(3):201-7. doi: 10.1136/tobaccocontrol-2011-050231

Matt GE, Quintana JP, Hovell MF, et al. Residual tobacco smoke pollution in used cars for sale: Air, dust, and surfaces. Nicotine & Tobacco Research. 2008;10(9):1467-1475. doi: 10.1080/14622200802279898

Quintana PJE, Matt GE, Chatfield D, et al. Wipe sampling for nicotine as a marker of thirdhand tobacco smoke contamination on surfaces in homes, cars, and hotels. Nicotine & Tobacco Research. 2013;15(9):1555–63. doi: 10.1093/ntr/ntt014

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

Like secondhand smoke, thirdhand smoke exposure is toxic for pets. Pets can be exposed to thirdhand smoke by:

• Swallowing thirdhand smoke stuck to their fur, feathers, or scales when self-grooming. 
• Inhaling toxic particles from the air. 
• Ingesting water or food from bowls or tanks that nicotine dissolved in.

The best way to protect your pet from thirdhand smoke is to never smoke in or around your home and to ban smoking in your home. If someone in your home smokes, ask them to smoke outdoors, away from doors and windows. Request that they wash their hands and change clothes when returning inside.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

The harmful effects of thirdhand smoke exposure on people can also be harmful to cats, dogs, and even birds and fish.  Many pet owners protect their pets from inhaling toxic chemicals in secondhand smoke, but fewer owners know about the harms of thirdhand smoke on their furry, feathered, or scaly friends.

Protecting Furry Friends, like Cats and Dogs, from Thirdhand Smoke Exposure

If your furry friend spends time indoors in an environment that contains thirdhand smoke, they will be exposed to the toxic chemicals. Secondhand smoke sticks on the fur of animals. Thirdhand smoke residue can also be transferred onto their fur if pets sleep or play on floors, furniture, or clothes polluted with thirdhand smoke. The residue can be absorbed into their skin or be ingested when they lick their fur. Cats and dogs can also inhale thirdhand smoke chemicals that off-gas from carpets, furniture, blankets, and other polluted surfaces.  

Here are three research studies to demonstrate the risks of thirdhand smoke exposure to cats and dogs.

1. Researchers examined the fur of cats who either lived with people who do not smoke or with people who do smoke (either indoors or outdoors). The study determined that cats with more exposure to second- and thirdhand tobacco smoke in their homes had an increased amount of nicotine in their fur compared to cats with less exposure. The more cigarettes the owner smoked, the higher the nicotine level in the cat’s fur. The location where the owners smoked also mattered. Cats whose owners smoked inside the home had higher levels of nicotine in their fur than cats whose owners smoked outside or not at all. Other studies have shown that tobacco smoke toxicants increase the risk of cancer in cats. 

1. A study of dogs showed that a dog’s breed influences the health effects of tobacco smoke exposure. A dog’s nose acts like a filter. Dogs with shorter noses have a smaller “filter,” so toxic particles are not stopped in the nose and can more easily get into the lungs, where they can cause harm. Dogs with longer noses have a larger “filter,” so more of the toxic particles are stopped before they get to the lungs. However, the particles can get stuck in the nose and sinuses, where they can cause harm. 

1. Researchers found that dogs living in homes where the owner’s smoked cigarettes were more likely to get bladder cancer than dogs who lived in smokefree homes. The study took a sample of 120 Scottish Terriers and considered the amount of cigarette smoke exposure and rates of bladder cancer. Terriers that lived in homes where people smoked were more likely to have bladder cancer than terriers who lived in homes where no one smoked. Among the terriers who lived in homes where someone smoked, the more the owner smoked the greater the likelihood of bladder cancer in the dog.

But what about household pets who don’t have fur?

Protecting Feathered and Scaly Friends, like Birds and Fish, from Thirdhand Smoke Exposure

Birds and fish also need protection from toxic thirdhand smoke. Just like humans, birds can be exposed to thirdhand smoke through breathing, eating, and coming in contact with tobacco residue on their bedding, perches, or toys. Birds are sensitive to air pollution. Birds can develop breathing problems, such as allergies, pneumonia, and sinus irritation, when they are exposed to air polluted by tobacco smoke.

Birds can unintentionally eat toxic thirdhand smoke residue. If their feathers have been coated with thirdhand smoke, they will ingest it as they groom or preen. If they perch on the clothes or skin of someone who has smoked, they can absorb thirdhand smoke through their feet or ingest it as they preen someone’s hair. Along with a variety of health problems, birds exposed to tobacco smoke can develop feather plucking, a condition that is very difficult to treat.

Thirdhand smoke can hurt fish, too. Because nicotine is toxic to fish and easily dissolves in water, it can contaminate the water in the tank and poison the fish. If fish are exposed to nicotine, they may get muscle spasms, rigid fins, lose their color, or die.

The best way to protect yourself and your pet from second- and thirdhand smoke is to ban smoking inside your home. If you do smoke, do your best to quit (support is available at 1-800-QUITNOW, and 1-800-300-8086 at Kick It CA) and enforce a smoking ban in your home. However, if you or a visitor do smoke, do so outside at least 50 feet away from the house. When returning inside after smoking, whoever was smoking should immediately wash their hands and change their clothing.

Updated: March 2025

Sources:

Bertone ER, Snyder LA, Moore AS. Environmental tobacco smoke and risk of malignant lymphoma in pet cats. American Journal of Epidemiology. 2002;156(3):268-273. doi: 10.1093/aje/kwf044

Bertone-Johnson ER, Procter-Gray E, Gollenberg AL, et al. Environmental tobacco smoke and canine urinary cotinine level. Environmental Research. 2008;106:361-364. doi: 10.1016/j.envres.2007.09.007 

Iosr J, Sandhya K, Patil S. Toxic effect of cigarette smoke on vital organs of aquarium fish carassius auratus. IOSR Journal of Environmental Science, Toxicology and Food Technology. 2015;9(10):10-12. doi: 10.9790/2402-091021012

Knapp DW, Dhawan D, Ruple A, et al. Association between cigarette smoke exposure and urinary bladder cancer in Scottish terriers in a cohort study. The Veterinary Journal. 2024;303:106044. doi: 10.1016/j.tvjl.2023.106044

Roza MR, Viegas CA. The dog as passive smoker: Effects of exposure to environmental cigarette smoke on domestic dogs. Nicotine & Tobacco Research. 2007;9(11):1171-1176. doi: 10.1080/14622200701648391 

Secondhand and (Third-hand) Smoke May Be Making Your Pet Sick. US Food and Drug Administration. 2016. Retrieved from: https://www.fda.gov/consumers/consumer-updates/secondhand-and-third-hand-smoke-may-be-making-your-pet-sick 

Slaughter E, Gersberg RM, Watanabe K, et al. Toxicity of cigarette butts, and their chemical components, to marine and freshwater fish. Tobacco Control. 2011;20:25-29. doi: 10.1136/tc.2010.040170

Smith VA, McBrearty AR, Watson DG, et al. Hair nicotine concentration measurement in cats and its relationship to owner-reported environmental tobacco smoke exposure. The Journal of Small Animal Practice, 2017;58(1):3–9. doi: 10.1111/jsap.12616

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

Similar to tobacco smoke, cannabis smoke comes from burning plant material. Current studies suggest that cannabis smoke sticks to surfaces, collects in dust, and absorbs into materials. Cannabis and tobacco smoke residue have some of the same toxic chemicals that are dangerous to breathe in, touch, or ingest.  The aerosols from nicotine and cannabis vapes also create a similar residue that remains on surfaces and in dust.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. Thirdhand smoke can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

Cannabis smoke is a newer area of study for scientists. Current studies suggest that smoking or vaping cannabis leaves behind a thirdhand chemical residue that is similar to the residue from smoking or vaping tobacco products. The thirdhand chemical residue from cannabis has some of the same cancer-causing chemicals as the residue from tobacco.

THC is the active ingredient in cannabis that produces the “high.” In rooms where cannabis has been smoked or vaped, THC accumulates on surfaces, collects in dust, and soaks into materials. Although exposure to cannabis-related thirdhand chemical residue will not get someone “high,” the residue contains many toxic chemicals that are dangerous to breathe in, touch, or ingest.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: March 2025

Sources:

Huang AS, Murphy MBC, Jacob P, et al. PM2.5 concentrations in the smoking lounge of a cannabis store. Environmental Science & Technology Letters, 2022; 9(6):551–556. doi: 10.1021/acs.estlett.2c00148

Moir D, Rickert WS, Levasseur G, et al. A comparison of mainstream and sidestream marijuana and tobacco cigarette smoke produced under two machine smoking conditions. Chemical Research in Technology. 2008;21(2):494-502. doi: 10.1021/tx700275p 

Sempio C, Lindley E, Klawitter J, et al. Surface detection of THC attributable to vaporizer use in the indoor environment. Scientific Reports. 2019;9(1):18587. doi: 10.1038/s41598-019-55151-5

Tang X, Cancelada L, Rapp VH, et al. Emissions from heated terpenoids present in vaporizable cannabis concentrates. Environmental & Science Technology. 2021;55(9):6160–70. doi: 10.1021/acs.est.1c00351

Wylie ADL, Abbatt JPD. Heterogeneous ozonolysis of tetrahydrocannabinol: Implications for thirdhand cannabis smoke. Environmental & Science Technology. 2020;54(22):14215–23. doi: 10.1021/acs.est.0c03728

Yeh K, Li L, Wania F, et al. Thirdhand smoke from tobacco, e-cigarettes, cannabis, methamphetamine and cocaine: Partitioning, reactive fate, and human exposure in indoor environments. Environment International, 2022;160:107063. doi: 10.1016/j.envint.2021.107063

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

While there are policies protecting federal employees and the public visiting federal facilities, there are no federal policies protecting private-sector employees from tobacco smoke exposure. However, there are policies on the state and local levels. Some states and local municipalities have comprehensively banned smoking in the workplace, whereas others have partial or no bans. Regardless of the state or local policy, some employers may have voluntary smoking bans in their workplace. These policies only prevent secondhand smoke exposure and the accumulation of new thirdhand smoke. They typically do not protect employees from thirdhand smoke already present in the workplace.

In California, 28 other states, and Washington, D.C., employers cannot refuse to hire someone based on their legal activities outside the workplace, including smoking and vaping. However, if the job will be impacted by smoking or vaping, employers in these states can still require employees not to smoke or vape and choose not to hire people who smoke or vape. For example, hospitals can choose to hire only medical providers who do not smoke or vape so they do not expose patients to tobacco smoke pollutants.

If you are concerned about thirdhand smoke in your workplace, talk to your employer about creating workplace policies to protect nonsmoking employees. You can find resources from organizations including the Thirdhand Smoke Resource Center, American Cancer Society, Public Health Law Center, American Nonsmoker Rights Association, and your local Tobacco Control and Health Departments.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. Thirdhand smoke can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

Executive Order 13058, “Protecting Federal Employees and the Public from Exposure to Tobacco Smoke in the Federal Workplace,” bans smoking in all Executive Branch facilities, all interior space owned, rented, or leased space by the Executive Branch of the Federal government. Federal law also prohibits smoking on all commercial passenger flights in the United States, including international flights.

However, federal law does not explicitly protect private-sector employees in the workplace. To date, workplace smoking bans only occur at the state and local levels. Some states and local municipalities have comprehensively banned smoking in the workplace, while others have partial or no bans. Employers may ban smoking in the workplace, even in states that do not have any statewide bans. Smoking bans protect workers from secondhand smoke and the build-up of new thirdhand smoke, but they do not protect against thirdhand smoke that is already there. 

In California, 28 other states, and Washington D.C., employers may not discriminate against employees for legal activities outside the workplace, like smoking and vaping. An employer in these states cannot refuse to hire someone because they smoke or vape unless not smoking and not vaping is a job requirement. For example, a medical office could choose to hire only medical providers who do not smoke to protect their patients from exposure to tobacco smoke pollutants. 

Even in states where employers can refuse to hire people who smoke, very few employers do. One exception, however, is Alaska Airlines, which, since 1985, has required all employees not to smoke at all. Similarly, in February 2020, U-Haul started requiring all new employees not to use any nicotine products. These policies ensure that employees are not bringing toxic thirdhand smoke residue with them into their workplace.

An increasing number of hospital systems nationwide are adopting this hiring practice. About 20% of hospitals in the US now refuse to hire people who smoke. The World Health Organization has also adopted this policy. These hiring policies protect all workers, patients, clients, and customers from second- and thirdhand smoke exposure. The practice also encourages tobacco cessation among people who do smoke.

If you are concerned about thirdhand smoke exposure at work, we encourage you to educate co-workers and supervisors about thirdhand smoke. We also recommend reviewing your state and employer’s policies and asking for protection from tobacco smoke exposure. Common protection policies include separating employees who do and do not smoke into different work areas and improving ventilation systems. Consider citing the ADA Act when proposing changes in workplace accommodations regarding tobacco smoke exposure. 

Protection from thirdhand smoke is essential for employees with a greater risk to the health effects of exposure, such as employees with asthma or who are pregnant. Organizations, including the American Lung Association, American Cancer Society, Thirdhand Smoke Resource Center, Public Health Law Center, American Nonsmoker Rights Association, and your local Tobacco Control Coalition and Health Department, can provide resources to help employees. 

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: March 2025

Sources

Patell R, Schmidt H. Should employers be permitted not to hire smokers? A review of US legal provisions. International Journal of Health Policy and Management. 2017;6(12):701-706. doi: 10.15171/ijhpm.2017.33 

Smoking and the Workplace. Workplace Fairness. 2024. Retrieved from: https://www.workplacefairness.org/smoking-rights-workplace/ 

Taylor WC. Nonsmoking and nonobesity hiring policies and practices: A comparative analysis. Indian Journal of Pharmaceutical Sciences. 2023;15:26. doi: 10.5539/ijps.v15n3p26 

There is No Constitutional Right to Smoke or Toke. Public Health Law Center. 2019. Retrieved from: https://www.publichealthlawcenter.org/sites/default/files/resources/No-Constitutional-Right-Smoke-Toke-2019.pdf 

U-Haul to Implement Nicotine-Free Hiring Policy for Healthier Workforce. U-Haul. 2019. Retrieved from: https://www.uhaul.com/Articles/About/19926/U-Haul-To-Implement-Nicotine-Free-Hiring-Policy-For-Healthier-Workforce/

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

Cigar smoke can absorb into surfaces and household objects, becoming thirdhand smoke. This thirdhand smoke residue from cigars contains similar harmful chemicals to thirdhand smoke residue from cigarettes.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. Thirdhand smoke can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

Cigars consist of a rolled bundle of dried tobacco leaves (the filler), the binder leaf holding the filler together, and the wrapper leaf. One cigar can contain over 15 grams of tobacco, which is 15 times more than the amount of one cigarette. Cigar tobacco has similar chemicals as cigarette tobacco but in different proportions. Cigars have more nitrogen compounds, ammonia, and tar than cigarettes. These compounds produce cancer-causing substances called tobacco-specific nitrosamines. 

Cigars make large quantities of secondhand smoke.  Secondhand smoke is what creates toxic thirdhand smoke. Like thirdhand smoke from cigarettes, thirdhand smoke from cigars can become embedded in surfaces, clothes, carpets, furniture, and walls. The thirdhand smoke residue can remain on surfaces and in dust for years after the smoking stops. Further, exposure to thirdhand smoke from cigars is harmful to one’s health.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: March 2025

Sources:

Baker F, Ainsworth SR, Dye JT, et al. Health risks associated with cigar smoking. JAMA. 2000;284(6):735-740. doi: 10.1001/jama.284.6.735

National Cancer Institute. Cigars: Health Effects and Trends. Tobacco Control Monograph No. 9. 1998;NIH Pub. No. 98-4302. Retrieved from: https://cancercontrol.cancer.gov/brp/tcrb/monographs/9/index.html

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

Since thirdhand smoke remains on surfaces and in dust for years, you can be exposed to thirdhand smoke even if no one around you smokes. Researchers have found thirdhand smoke in many places where people do not smoke, such as the homes of people who have strict no-smoking rules, non-smoking rooms at hotels that allow smoking in designated areas, used cars in which previous owners smoked, and apartments in which previous tenants smoked. 

Thirdhand smoke residue has also been found in places where smoking is not allowed, such as rental cars, movie theaters, and even neonatal intensive care units. People who smoke can carry thirdhand smoke residue on their skin, clothes, hair, and breath. They then bring the residue into these smokefree places.

Enforcing a strict no-smoking rule in your car and home can help reduce thirdhand smoke exposure. Asking people who smoke to wash their hands and change into clean clothes before entering these spaces can also help reduce exposure.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. Thirdhand smoke can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

You can still be exposed to thirdhand smoke if nobody around you smokes. After smoking stops, tobacco smoke residue can remain on surfaces and in dust for years. You can be exposed to thirdhand smoke by touching polluted surfaces, breathing off-gassed particles, and swallowing particles on polluted objects. Thirdhand smoke sticks to clothes, skin, and hair. When people exposed to tobacco smoke go into a smokefree environment (e.g., workplace, elevator, hospital, airplane), they carry thirdhand smoke residue into that space, exposing others to the toxic residue. 

Researchers have found thirdhand smoke in homes with strict no-smoking rules. The residue could have been transported there by visitors who had previously smoked and brought it inside on their skin, clothes, and hair, or the residue could have remained there from the previous residents who smoked. Researchers also found thirdhand smoke in homes years after current occupants quit smoking. Researchers have detected thirdhand smoke in non-smoking rooms at hotels that allow smoking in designated areas and inside used cars in which previous owners smoked.

Thirdhand smoke persists in environments with smoking bans that are frequented by people who smoke, including rental cars and movie theaters. Surprisingly, scientists discovered thirdhand smoke in neonatal intensive care units (NICUs) and other high-risk hospital settings. Visitors carried thirdhand smoke residue into the hospital, exposing the infants to the toxic chemicals.

People’s previous behavior in an enclosed space can leave behind a toxic legacy that can expose others to thirdhand smoke even if no one around them is smoking. Enforcing strict no-smoking rules in your car and home can help reduce exposure. Asking people who smoke to wash their hands and change into clean clothes before entering these spaces can also help reduce exposure.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: March 2025

Sources:

Matt GE, Quintana JP, Zakarian JM, et al. When smokers move out and non-smokers move in: Residential thirdhand smoke pollution and exposure. Tobacco Control. 2011;20(1). doi: 10.1136/tc.2010.037382

Matt GE, Quintana JP, Hovell MF, et al. Residual tobacco smoke pollution in used cars for sale: Air, dust, and surfaces. Nicotine & Tobacco Research. 2008;10(9):1467-1475. doi: 10.1080/14622200802279898 

Matt GE, Quintana PJE, Hoh E, et al. Persistent tobacco smoke residue in multiunit housing: Legacy of permissive indoor smoking policies and challenges in the implementation of smoking bans. Preventive Medicine Reports. 2020;18. doi: 10.1016/j.pmedr.2020.101088

Northrup TF, Stotts AL, Suchting R, et al. Thirdhand smoke contamination and infant nicotine exposure in a neonatal intensive care unit: An observational study. Nicotine & Tobacco Research. 2021;23(2):373–82. doi: 10.1093/ntr/ntaa167

Sheu R, Stönner C, Ditto JC, et al. Human transport of thirdhand tobacco smoke: A prominent source of hazardous air pollutants into indoor nonsmoking environments. Science Advances. 2020;6(10). doi: 10.1126/sciadv.aay4109 

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body through your lungs, skin, and mouth. Getting rid of it is really hard and can cost a lot of money. 

When people smoke inside their home, the chemicals in tobacco smoke build up over time and leave toxic thirdhand smoke residue on carpets, furniture, walls, doors, and ceilings. This can decrease the value of a home by as much as 30%. To maintain the value of your home, never allow smoking or vaping on your property.  

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

When people smoke inside their home, the chemicals in tobacco smoke build up over time and leave toxic thirdhand smoke residue on carpets, furniture, walls, doors, and ceilings. This toxic residue lingers long after smoking stops and can remain after previous residents who smoked move out. Real estate agents know that evidence of smoking in a home — the smell of stale tobacco or stains on walls or fabrics — can reduce the selling price of a home by as much as 30%. That means if you live in a neighborhood where most homes sell for about $500,000, a similar home that smells like stale tobacco smoke will sell for around $350,000.

There are a few reasons why homes that have been smoked in often sell for less money.

• Most people do not like the smell of stale tobacco smoke. 
• Many people experience negative physical symptoms when they smell stale tobacco smoke, such as shortness of breath, headaches, sore throat, or earaches. 
• It is difficult and expensive to remove the toxic thirdhand smoke residue.
• When homes are heavily polluted with thirdhand smoke, the buyer may have to pay for a full gut remodel to create a healthy home free of tobacco chemicals.

Most people want to buy houses that have not been smoked in, reducing the pool of potential buyers for a home where someone smoked. With fewer potential buyers, there is less competition among potential buyers. Because real estate agents recognize that it is more difficult to sell a home that smells like stale tobacco smoke, it may be difficult to find an agent willing to list the home.

Required disclosure documents in many states, including California, currently do not ask about the smoking history of a home. However, the California Association of Realtors uses an additional document, called the Seller Property Questionnaire, that does ask sellers to disclose if they are aware of “any occupant of the property smoking or vaping any substance on or in the property, whether past or present.”

Even though few jurisdictions require tobacco use disclosure, most buyers and real estate agents are familiar with the signs of indoor smoking and understand the challenges of cleaning thirdhand smoke inside a home. 

If you own a home and someone in your household smokes or vapes, you should ask them to 

• never smoke or vape inside the home and 
• move far enough away from windows and doors that tobacco smoke and vape aerosols cannot drift back in the home. 

A complete indoor smoking and vaping ban is the single most important strategy to reduce the build-up of thirdhand smoke.  

Depending on how much thirdhand smoke has accumulated, cleaning may be insufficient, and a full remediation may be required. Remediation includes drastic (and often expensive) measures, such as the removal and replacement of carpets, drywall, wall insulation, flooring, built-in furniture and doors, and the heating and air conditioning system.

If you are buying a home, you should:

• Ask the seller’s agent about the smoking history of the home.
• Inquire if there is an excessive use of air fresheners or candles.
• Ask the home inspector to look for signs of tobacco use.

Tobacco smoke residue can significantly decrease your home’s value. To avoid bad news when you sell your home, don’t allow smoking or vaping on or in your property. If thirdhand smoke has already accumulated, consult a remediation expert to make necessary repairs and improvements. You’ll also want to disclose the information to your real estate agent and buyer. 

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: March 2025

Sources: 

Klassen AC, Lee N, Lopez JP, et al. Realtors as partners in tobacco control: Results from a Pennsylvania survey. Tobacco Regulatory Science. 2020;6(6):392-404. doi: 10.18001/TRS.6.6.3 

Matt GE, Quintana PJ, Zakarian JM, et al. When smokers move out and non-smokers move in: Residential thirdhand smoke pollution and exposure. Tobacco Control. 2011;20(1):e1. doi: 10.1136/tc.2010.037382

Seller Property Questionnaire. California Association of Realtors. 2023. https://thirdhandsmoke.org/wp-content/uploads/2024/11/SPQ.pdf

Getting Rid of Cigarette Smell in Your Home. This Old House. https://www.thisoldhouse.com/home-safety/21249597/understanding-thirdhand-smoke

Ura, Karley. Up in smoke: Smoking in the home can lower resale value by tens of thousands. Cision. 2013. https://www.newswire.ca/news-releases/up-in-smoke-smoking-in-the-home-can-lower-resale-value-by-tens-of-thousands-512275021.html

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

Pipe tobacco smoke has many of the same harmful chemicals as cigarette smoke. Like thirdhand smoke from cigarettes, smoke from pipes sticks to and embeds in many surfaces, including clothes, furniture, walls, and household objects. 

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

Many people think that smoking a pipe is safer than smoking regular cigarettes, but pipe tobacco is also harmful to your health. People who smoke pipes have an increased risk of head, neck, liver, and lung cancer.

The secondhand smoke from smoldering tobacco in the bowl of a pipe and the smoke exhaled by the person smoking contain many of the same toxic chemicals as cigarette smoke, including nicotine. Exposure causes cancer in humans and is especially dangerous to pregnant women and young children. 

Just like secondhand smoke from cigarettes, secondhand smoke from a pipe creates toxic thirdhand smoke residue that sticks to surfaces, clothes, carpets, furniture, and walls. Over time, toxic thirdhand smoke residue from pipe smoke builds up and becomes embedded in indoor environments.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: March 2025

Sources:

Jacob P 3rd, Benowitz NL, Destaillats H, et al. Thirdhand smoke: New evidence, challenges, and future directions. Chemical Research in Toxicology. 2017;30(1):270-294. doi: 10.1021/acs.chemrestox.6b00343

Yeh K, Li L, Wania F, et al. Thirdhand smoke from tobacco, e-cigarettes, cannabis, methamphetamine and cocaine: Partitioning, reactive fate, and human exposure in indoor environments. Environment International. 2022;160:107063. doi: 10.1016/j.envint.2021.107063

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

You may be able to look online to see if a hotel, Airbnb, or other short-term stay spot is smokefree. However, it is often unclear what that exactly means.

We recommend that you ask these follow-up questions:

• Where is smoking allowed (rooms, common areas, patio, balcony, outside)?
• What is the penalty for smoking where it is not allowed?
• How are guests informed of the nonsmoking/smoking policy?

If smoking is not allowed anywhere on the property, guests are adequately informed of the policy, and there is a hefty penalty for violators, you can feel comfortable making a reservation. If not, consider a different hotel.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. Thirdhand smoke can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

Whether traveling for business or pleasure, some research and a few simple steps will maximize your chances of finding smokefree accommodations in hotels, short-term rentals, bed & breakfasts, or Airbnbs. 

The Internet is a great source for information, but you will learn more about the smokefree status of a place from a phone call with an employee.

When you call, ask if smoking or vaping is allowed anywhere on the property. The ideal answer to this question is: “No, we are a 100% smokefree property inside and out.” Great! Go ahead, make your reservation.

More likely, the answer will be: “Yes, we allow smoking in some places.” If that’s the case, you need to find out exactly where smoking is allowed. Because smoke can travel easily through windows, air ducts, hallways, and other indoor environments, it is likely that tobacco smoke residue could broadly contaminate the property, even if there are dedicated smokefree rooms.

If smoking is allowed in some areas, ask these follow-up questions:

• Is smoking allowed in any of the rooms?  
• What is the penalty for violating the non-smoking policy? 
• Are there signs posted in each room about the non-smoking policy, including the penalty for violating?

If smoking is not allowed in any room or nearby, there are posted no-smoking signs, guests are adequately informed of the policy, and there is a hefty penalty for violators, you can feel comfortable making a reservation. If smoking is allowed in or near any of the rooms, including indoor and outdoor common areas, look for another establishment.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: November 2024

Sources:

DeCarlo PF, Avery AM, Waring MS. Thirdhand smoke uptake to aerosol particles in the indoor environment. Sci Adv. 2018;9: 4(5): eaap8368. DOI: 10.1126/sciadv.aap8368.

Kennedy, H. R., Egan, C., & Welding, K., (2020). Assessing potential public health concerns in Airbnb venues in four Canadian cities. Journal of Environmental Health, 83(3), 8-12.

Matt GE, Quintana PJ, Fortmann AL, Zakarian JM, Galaviz VE, Chatfield DA, Hoh E, Hovell MF, Winston C. Thirdhand smoke and exposure in California hotels: non-smoking rooms fail to protect non-smoking hotel guests from tobacco smoke exposure. Tob Control. 2014 May;23(3):264-72. doi: 10.1136/tobaccocontrol-2012-050824. Epub 2013 May 13. PMID: 23669058.

McDaniel PA, Malone RE. You Want Your Guests to Be Happy in This Business: Hoteliers’ Decisions to Adopt Voluntary Smoke-Free Guest-Room Policies. Am J Health Promot. 2018 Nov;32(8):1740-1746. doi: 10.1177/0890117118763742.

Quintana PJE, Matt GE, Chatfield D, Zakarian JM, Fortmann AL, Hoh E. Wipe sampling for nicotine as a marker of thirdhand tobacco smoke contamination on surfaces in homes, cars, and hotels. Nicotine Tob Res. 2013 Sep;15(9):1555–63.

Weigel EA, Matt GE. When Hotel Guests Complain About Tobacco, Electronic Cigarettes, and Cannabis: Lessons for Implementing Smoking Bans. Tobacco Use Insights. 2022;15. doi:10.1177/1179173X221124900

Zakarian JM, Quintana PJE, Winston CH, Matt GE. Hotel smoking policies and their implementation: a survey of California hotel managers. Tob Induced Diseases. 2017 Oct 30;15:40. doi: 10.1186/s12971-017-0147-6.

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

There are many sources of air pollution, such as car and factory emissions. Tobacco smoke pollution, however, has an easier solution to reduce exposure than many other forms of air pollution. People may be more willing to make changes to reduce tobacco pollution, such as not smoking around others, than to make changes to reduce car emissions, such as not driving their cars. In addition, some chemicals in thirdhand smoke are only found in tobacco smoke, which means tobacco smoke is adding new cancer-causing chemicals to additional air pollution. To protect public health, we have to work to avoid thirdhand tobacco smoke exposure.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

There are many pollutants that can contaminate our environments, such as vehicle emissions and industrial air pollutants. Policymakers and the public often focus on these types of pollutants. However, there remain a lot of other forms of pollution to consider, such as pollutants from tobacco smoke. Addressing tobacco smoke pollution highlights a preventable cause of harm, in this case smoking, that can be changed or eliminated to keep the environment clean and healthy. For example, it is much more reasonable to ask someone not to smoke around others than it is to ask someone not to drive a vehicle.

In addition, some of the toxic and cancer-causing chemicals in thirdhand smoke are only found in tobacco smoke. This means that thirdhand smoke adds a unique mixture of harmful substances to the ones already created by pollution from cars and factories. To prevent exposure to these additional pollutants, individuals should never allow smoking indoors or near a doorway or window.

Eliminating exposure to toxic pollutants is important for protecting human health. This means addressing many forms of air pollution, including tobacco smoke residue.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: December 2024

Sources:

Jacob P 3rd, Benowitz NL, Destaillats H, Gundel L, Hang B, Martins-Green M, Matt GE, Quintana PJ, Samet JM, Schick SF, Talbot P, Aquilina NJ, Hovell MF, Mao JH, Whitehead TP. Thirdhand Smoke: New Evidence, Challenges, and Future Directions. Chem Res Toxicol. 2017 Jan 17;30(1):270-294. doi: 10.1021/acs.chemrestox.6b00343.

Whitehead TP, Havel C, Metayer C, Benowitz NL, and Jacob 3rd P. Tobacco alkaloids and tobacco-specific nitrosamines in dust from homes of smokeless tobacco users, active smokers and nontobacco users. Chem Res Toxicol. 2015;28(5):1007-14.

Schick SF, Farraro KF, Perrino C, Sleiman M, van de Vossenberg G, Trinh MP, Hammond SK, Jenkins BM, Balmes J. Thirdhand cigarette smoke in an experimental chamber: evidence of surface deposition of nicotine, nitrosamines and polycyclic aromatic hydrocarbons and de novo formation of NNK. Tob Control. 2014;23(2):152-9.

The Short Answer:

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

To better your chances of buying a smokefree used car, follow these steps.

1. Ask questions:
   1. 1. Did the owner ever smoke in the car?
      2. Did the owner let others smoke in the car?
2. Inspect the vehicle:
   1. 1. Do you smell stale tobacco smoke or excessive fragrance that could be covering up an odor?
      2. Do you see any stains on the upholstery or burn marks on the seats or floor?
3. Consider the asking price:
   1. 1. Does it seem “too good to be true?”

If you answered “yes” to any of these questions, the car is likely polluted with thirdhand smoke. In most cases, it is impossible to remove the toxic thirdhand smoke chemicals from a car. Consider buying a different vehicle.

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. Thirdhand smoke can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

When people smoke in a car, thirdhand smoke residue builds up just the way it does in indoor environments. However, a car is a much smaller space, so the concentration of tobacco smoke chemicals is higher. This build-up happens even if the car’s ventilation system is on or the windows are open. In addition, a car’s interior contains more materials and surfaces, such as floor carpeting, seat fabrics, upholstery, and ceiling liners, that can absorb toxic tobacco residue. Once absorbed, these chemicals can be re-emitted into the air and settle in dust in the car. Once absorbed, these chemicals cannot be completely removed from the materials. Even if a car’s interior is cleaned frequently, the tobacco residue will remain in reservoirs embedded in the fabrics and upholstery. In addition, even if someone smokes only outside of the car, they can transfer thirdhand smoke into the car on their hands, skin, hair, and clothes. 

Before you “sign on the dotted line,” take these steps to help you determine if a prior owner allowed smoking inside the vehicle. 

1. Ask about prior smoking in the vehicle.
   Actively engage the seller in a discussion about prior smoking in the vehicle. If you are speaking with the owner, ask these two questions:  

1. 1. 1. Did you smoke in this car?  
      2. Did you let others smoke in this car?

Similarly, if you are speaking with a dealer, you should ask these questions:  

1. 1. 1. Did you ask the previous owner about smoking?  
      2. If not, can you find out if the previous owner ever smoked or allowed smoking in the car? 
      3. When you prepared the car for sale, did you notice any smell or other signs of tobacco use? 

Although asking is essential, it’s important to recognize that owners are not required to disclose previous smoking, and a dealer may not know about the previous owners’ smoking history. 

1. Inspect the vehicle.
   Get inside, close the doors and windows, and conduct your own inspection. 

1. 1. 1. First, smell. The odor of stale tobacco smoke means thirdhand smoke has accumulated in the vehicle. 
      2. Be cautious if you smell air fresheners or perfumed upholstery cleaners. It is not uncommon for a seller to use air fresheners or fragrances to disguise unpleasant odors. If you smell fragrances, ask why the seller is using them.  
      3. Look for stains, another sign of tobacco smoking in the car. Check along the edges of car panels or the ceiling liner for discoloration. 
      4. Check the seat covers and flooring for signs of small burns that could indicate accidentally dropped cigarettes or fallen ashes. 

1. Be cautious of a great deal.
   If the price is “too good to be true,” it just might be. The resale value is lower for cars that have been smoked in. An owner or dealer might offer a low price in order to sell the vehicle quickly. 

Going through these steps to ensure your vehicle is clean of toxic thirdhand smoke residue will not only protect your health but also the health of those who ride in it.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated November 2024

Sources: 

Continente X, Henderson E, Lopez-Gonzalez L. et al. Exposure to secondhand and thirdhand smoke in private vehicles: Measurements in air and dust samples. Environmental Research 2023; 235. doi: 10.1016/j.envres.2023.116681

Fortmann AL, Romero RA, Sklar M, et al. Residual tobacco smoke in used cars: futile efforts and persistent pollutants. Nicotine Tob Res 2010;12(10):1029-36. doi: 10.1093/ntr/ntq144 [published Online First: 2010/09/02] 

Matt GE, Fortmann AL, Quintana PJ, et al. Towards smoke-free rental cars: an evaluation of voluntary smoking restrictions in California. Tob Control 2013;22(3):201-7. doi: 10.1136/tobaccocontrol-2011-050231 

Matt GE, Quintana PJ, Hovell MF, et al. Residual tobacco smoke pollution in used cars for sale: air, dust, and surfaces. Nicotine Tob Res 2008;10(9):1467-75. doi: 10.1080/14622200802279898 

Matt GE, Romero R, Ma DS, et al. Tobacco use and asking prices of used cars: prevalence, costs, and new opportunities for changing smoking behavior. Tob Induc Dis 2008;4:2. doi: 10.1186/1617-9625-4-2 

Jacob P 3rd, Benowitz NL, et al. Thirdhand Smoke: New Evidence, Challenges, and Future Directions. Chem Res Toxicol. 2017 Jan 17;30(1):270-294. doi: 10.1021/acs.chemrestox.6b00343. Epub 2016 Dec 21. PMID: 28001376; PMCID: PMC5501723.

Pitten, L., Brüggmann, D., Dröge, J. et al. TAPaC—tobacco-associated particulate matter emissions inside a car cabin: establishment of a new measuring platform. J Occup Med Toxicol 17, 17 (2022). doi: 10.1186/s12995-022-00359-x

The Short Answer

Thirdhand smoke is the chemicals left behind when someone smokes tobacco. Thirdhand smoke is unhealthy for people and pets. It can stick around for a long time in homes and cars. It gets into your body if you inhale, swallow, or touch the chemicals. Getting rid of it is really hard and can cost a lot of money.

To better your chances of buying a home free of toxic thirdhand smoke pollution, follow these steps.

1. Talk with your real estate agent

• Make sure your real estate agent knows you will only consider a smokefree home.

2. Ask questions

• Did the previous occupants ever smoke in the home?
• Did the previous occupants let others smoke in the home?

3. Inspect the home

• Do you smell stale tobacco smoke or excessive fragrance that could be covering up an odor?
• Do you see any stains on the walls or burn marks on the carpeting, floor, or other surfaces?

4. Consider the asking price

• Does it seem “too good to be true?”

If you answered “yes” to any of these questions, consider buying a different home or make your offer contingent on a home inspection and contractor estimate of renovation.  

The Long Answer:

Thirdhand smoke is the chemical residue from tobacco smoke. It is also called “tobacco smoke residue” or “stale tobacco smoke.” The chemicals in thirdhand smoke are toxic to humans, especially children. It can linger for years in dust and on household surfaces. It can also become embedded in carpets, furniture, clothes, and building materials. It is difficult and expensive to remove.

When looking for your new home, it is important to determine if a house is polluted with thirdhand smoke chemicals. Take these steps to help you determine if the sellers have allowed smoking inside the home or on the property. 

Talk with your real estate agent

Before viewing any homes, make sure your real estate agent knows you will only consider a smokefree home. This way, your agent can save you time and show you only homes that likely do not contain thirdhand smoke residue.

Ask questions

Ask the sellers’ agent about the sellers’ tobacco and vaping use as well as use by previous residents. Be sure to ask about use inside the home as well as anywhere on the property (i.e., yard, patio, and garage). 

• Did the previous occupants smoke or vape in the home?  
• Did the previous occupants let others smoke or vape in the home?
• Did the previous occupants or others smoke or vape anywhere on the property (e.g., yard, porch, patio, garage)?
• To the best of the sellers’ knowledge, did prior occupants smoke in the home or on the property?

If the real estate agent does not know the answers, ask them to check with the sellers and get back to you with an answer. Although asking is essential, it’s important to recognize that sellers may not be legally required to disclose previous smoking history, and they may not know about the previous occupants’ smoking history. 

If the sellers or previous residents smoked or vaped inside, thirdhand smoke is likely to be in the home. Even if they smoked outside, they could have carried thirdhand smoke residue into the home on their hands, skin, hair, and clothes. In addition, the longer and more frequently someone smoked in or around a home, the more thirdhand smoke residue there will be.

Inspect the home

Look for signs that someone smoked in the home. These signs include the smell of stale tobacco smoke; nicotine stains on walls; burn marks on rugs, flooring, or other surfaces; and other evidence of smoking, such as ashtrays and discarded cigarette butts on the property. 

• Observe for stains around electrical outlets and light switches as well as behind pictures on the walls.
• Close the doors and windows, turn off fans, and turn on the heating system to check for stale tobacco odor. 
• Note the presence of strong fragrances that may be used to mask the smell of stale tobacco. Ask why the seller is using them. Schedule a second visit when fans and fragrances are not in use.
• Inspect the property for signs of smoking outside, such as ashtrays or discarded cigarette butts. 

Consider the asking price

• Be skeptical if the asking price seems “too good to be true.” The selling price of homes that contain thirdhand smoke is often lower than homes that do not contain thirdhand smoke. A seller might agree to a lower listing price to make sure the home sells quickly.

No matter what you have observed in the home, make sure your purchase offer is contingent on a home inspection that includes an assessment of tobacco or vape use in the home and on the property. 

If there are signs of thirdhand smoke, you can consider walking away from the deal or obtaining contractor estimates for renovation to remove the thirdhand smoke pollution. In many cases, it is difficult and expensive to remove the toxic thirdhand smoke chemicals from a home. 

Once you find your smokefree home, be sure to thank your real estate agent for helping you protect your health and the health of those who will live in the home with you.

Do you have more questions about the toxic legacy of tobacco smoke, how it affects human health, and what we can do about it? Learn more here.

Updated: July 2025

Sources: 

DeCarlo PF, Avery AM, Waring MS. Thirdhand smoke uptake to aerosol particles in the indoor environment. Science Advances. 2018;9:4(5):eaap8368. doi: 10.1126/sciadv.aap8368

Mahabee-Gittens EM, Merianos AL, Quintana PJE, et al. Nicotine on children’s hands: Limited protection of smoking bans and initial clinical findings. Tobacco Use Insights. 2019;12. doi: 10.1177/1179173X18823493

Matt GE, Quintana PJE, Zakarian JM, et al. When smokers move out and non-smokers move in: Residential thirdhand smoke pollution and exposure. Tobacco Control. 2011;20(1):e1. doi: 10.1136/tc.2010.037382

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Quintana PJE, Matt G, Chatfield D, et al. Wipe Sampling for Nicotine as a Marker of Thirdhand Tobacco Smoke Contamination on Surfaces in Homes, Cars, and Hotels. Nicotine & Tobacco Research. 2013;15(9):1555-1563. doi: 10.1093/ntr/ntt014