What Can I Do to Avoid Thirdhand Smoke When Buying a House in California?

A team at the Thirdhand Smoke Resource Center examined home disclosure documents commonly used in San Diego to see how well they inform buyers about the smoking history of their potential home. Home buyers typically receive disclosure documents listing problem areas in the house, and many choose to get a home inspection before officially buying. For structural issues, lead, and mold, they are probably protected. For thirdhand smoke, however, they aren’t as protected as they might think.

Thirdhand smoke is the chemical residue that is left behind on clothes, skin, furniture, walls, and other surfaces after someone smokes. It contains nicotine and other cancer-causing chemicals and can be absorbed, inhaled, and even ingested by people exposed to it. 

If previous residents of a home smoked, the toxic chemicals in thirdhand smoke may remain in the home long after they moved out. Thirdhand smoke is difficult to remove, and the more someone smokes in a home, the more thirdhand smoke there is. Disclosure statements can be an important tool for buyers to learn the smoking history of a home and consider ways to clean and remodel as necessary, but these disclosures often don’t provide the full story to the buyer. Here is what we found from the three disclosure documents that we reviewed. 

Disclosure Laws Disregard Tobacco Smoke

California, like many states, requires its home sellers to disclose written details about the property they are selling. Disclosure laws require the seller and the agent to tell potential buyers about issues such as structural problems, faulty smoke alarms, or leaky roofs. The problems that sellers must disclose are listed on the California Department of Real Estate’s Transfer Disclosure Statement.  Sellers must also disclose natural hazards, such as if the home is near an earthquake fault line or in an area susceptible to wildfires. They also have to share noise issues in the neighborhood as well as if the home is/was exposed to airport pollution, mold, lead, or methamphetamine.

Sellers must disclose damage from fires as well, such as burns and smoke damage. But smoke damage and thirdhand smoke from tobacco products? Not so much.

Sellers are typically not required to reveal damage from tobacco products nor past or current smoking in or around the home. A buyer could have no idea that their new home is full of thirdhand smoke – even if the seller does. 

If a seller fails to provide or misrepresents on the Transfer Disclosure Statement, they are liable for paying for any damages that occur to the home because the buyer did not know about the problem. The seller could also be subject to additional fees on top of paying for the damages as punishment. In some cases, the buyer can even cancel their home purchase, forcing the seller to take back the property and return any funds the buyer has paid.

The seller’s real estate agent also has a required disclosure document called the Agent Visual Inspection Disclosure. However, this document is limited and does not include disclosing tobacco smoke. In fact, it specifically says the “Agent will not determine if the Property has mold, asbestos, lead or lead-based paint, radon, formaldehyde or any other hazardous substance or analyze soil or geologic condition.” The agent is limited to inspecting problems that are easily seen, such as structural issues. 

Seller Property Questionnaire Can Offer Information – But It’s Not Legally Required

Unlike many other states, some California realtors collect a second disclosure document from sellers. This document is called the Seller Property Questionnaire, and it actually provides at least a bit of information about the smoking history in the home to the buyer. 

Real estate agents in the California Association of Realtors (CAR) agree to include this additional disclosure questionnaire when they join CAR. The questionnaire provides information about more topics than the Transfer Disclosure Document does, such as if any pets lived in the home. 

Completed by the seller, Section M, Question 2 of the Seller Property Questionnaire asks if “any occupant on the Property smoked on or in the Property?” Sellers must check the appropriate “Yes” or “No” box based on their current knowledge about the house. If the seller answers 
“Yes,” they are supposed to provide an explanation in the space provided below the question.

There are more than 435,000 real estate agents in California as of September 2023, but less than 50% are in the California Association of Realtors. That means that only half of California’s realtors are asking sellers to complete CAR’s Seller Property Questionnaire. Or, stated another way, one-half of realtors in CA do not routinely collect information on a home’s smoking history.

Of course, this questionnaire is not legally required and is only enforced by CAR contracts. If a seller doesn’t want to fill out this form, they can try to modify the terms of their CAR purchase agreement, according to the CAR website. This is typically done through a counteroffer.

Buyer Beware

Clearly, buyers have to put in the effort to make sure their potential home is free of thirdhand smoke. Here are some tips to make the process a little easier:

Tip #1: Before you even start house hunting, ensure your agent is a California Association of Realtors member.

While other real estate agents may be able to help you find a house, only realtors in the California Association of Realtors have agreed to use the Seller Property Questionnaire. CAR realtors also have access to additional training and materials through their membership to stay up-to-date.

Tip #2: When viewing homes, look for signs that previous occupants smoked tobacco in the home. 

Unfortunately, currently available commercial tests are not sensitive enough to test for nicotine levels seen in research with thirdhand smoke. However, there are some things to look (and smell) for without a test:

  • One of the strongest indicators that someone smoked in a home is the smell of stale tobacco smoke. After smoke absorbs into materials around the home, the thirdhand smoke chemicals can be released back into the air, producing a stale tobacco smell. It is important to note that some thirdhand smoke chemicals are odorless, so a lack of smell is not a guarantee that there is no smoke residue.

  • Another smell to watch out for is an excess of fragrances in the home, such as scented candles or spray. Some sellers and realtors will try to mask the smell of tobacco smoke with these. If you smell lots of fragrance, ask the seller why they are using it.

  • Since thirdhand smoke can stick to surfaces, look for stains on the walls, ceilings, and hardwood or laminate floors of the home. These stains will be an orangish-brown color. Unsure if the walls are stained? Compare the color of the exposed walls with a part of the wall behind a picture frame. 

  • Look for stains on fabrics around the home, such as couches, carpets, and curtains. These stains will also be an orangish-brown color.

  • Be particularly careful in a home that has been recently renovated, as the smell of fresh paint and new flooring will mask tobacco smoke.

Tip #3: Ask questions about the smoking history.

In the absence of required disclosure, the best approach today is to ask your own and the seller’s real estate agent directly about the smoking history of a property.  Put your questions in writing and request for the answers to be as well so you will have a record of them. Here are some questions to ask:

  • Have any previous occupants smoked tobacco outside the home?
  • Have any previous occupants smoked tobacco inside the home?
  • Have the previous occupants allowed guests to smoke inside the home?
  • Have the previous occupants had a complete smoking ban in the home?
  • Has the house ever been rented out? If so, when? (Renting the home to others makes it harder for the owners to fully report what has happened in it.)

Tip #4: When you decide on a home, make your offer contingent on a home inspection.

Hire a home inspector to look for signs of smoking by previous occupants. Specifically, look for a home inspector with experience dealing with homes that were damaged by tobacco smoke or fires. Ensure the inspector will include evidence of prior tobacco use in their report.

Tip #5: If the home you chose does have evidence of prior smoking, weigh the cost of remediation versus choosing a different home.

Cleaning up the chemical residue in thirdhand smoke depends on how much and how long occupants have smoked in a home.  If former occupants smoked in a home for years, a full gut remodel might be needed.  In such a case, the costs can easily reach tens of thousands of dollars, and a potential buyer might be better advised to look for a thirdhand smokefree home.  The home remodeling experts at Ask This Old House offer advice when considering cleaning up a thirdhand smoke-polluted home.

Looking ahead

Buyers could be better informed about thirdhand smoke if it was listed as a hazard in the California Environmental Protection Agency’s Residential Environmental Hazards Booklet. This guide provides information on common hazards in and around residential properties, such as lead, mold, carbon monoxide, and radon. Buyers, sellers, and agents can use this guide to learn more about these hazards and become better equipped to consider them when providing or asking for disclosures. If thirdhand smoke was included, more buyers, sellers, and agents would think about the smoking history of a home.

Another way to inform buyers is by adding questions about smoking history to the Transfer Disclosure Document. That way, all sellers would be required to disclose any smoking in the home. Either of these options would bring awareness to thirdhand smoke and protect people from thirdhand smoke exposure.


About the California Association of Realtors. RealTrends. 2023. https://www.realtrends.com/association-network-membership/california-association-of-realtors/#:~:text=Today%2C%20the%20CALIFORNIA%20ASSOCIATION%20OF,rigid%20code%20of%20professional%20ethics.

Disclosures in Real Property Transactions. California Department of Real Estate. 2005. https://www.dre.ca.gov/files/pdf/re6.pdf

Legal Remedies If a California Home Seller Conceals a Defect. Nolo. 2023. https://www.nolo.com/legal-encyclopedia/legal-remedies-if-california-home-seller-conceals-defect.html  

Licensee/Examinee Statistics for Fiscal Year 2023/2024. California Association of Realtors. 2023. https://www.dre.ca.gov/stats/2023-2024.html

Matt, G., Greiner, L., Record, R., et al. (2023). Policy-relevant differences between secondhand and thirdhand smoke: strengthening protections from involuntary exposure to tobacco smoke pollutants. Tobacco Control, 0:1-9. doi: 10.1136/tc-2023-057971

Quick Guide – Seller Property Questionnaire. California Association of Realtors. 2018. https://www.car.org/-/media/CAR/Documents/Transaction-Center/PDF/QUICK-GUIDES/Quick-Guide—Seller-Property-Questionnaire.pdf

Residential Environmental Hazards Booklet. California Environmental Protection Agency. 2011. https://www.cdph.ca.gov/Programs/CCDPHP/DEODC/CLPPB/CDPH%20Document%20Library/ResEnviroHaz2011.pdf

Seller Lied on Disclosure – California Real Estate Failure to Disclose. California Business Lawyer & Corporate Lawyer, Inc. https://california-business-lawyer-corporate-lawyer.com/real-estate-lawyer__trashed/seller-lied-on-disclosure-california-real-estate-failure-to-disclose/#:~:text=Punitive%20damages%20punish%20offenders%20for,and%20return%20the%20buyer%27s%20money.

Seller Property Questionnaire. California Association of Realtors. 2018. https://www.mylenemerlo.com/wp-content/uploads/2015/12/SPQ.pdf

Tavsibi, AO. California Brokers Disclosure Requirements on Property Defects to Home Buyers. Nolo. 2023. https://www.nolo.com/legal-encyclopedia/california-brokers-disclosure-requirements-property-defects-home-buyers.html

Tasvibi, AO. Selling a California Home: What Are My Disclosure Obligations? Nolo. 2023. https://www.nolo.com/legal-encyclopedia/residential-home-sellers-california-your-disclosure-obligations.html

Transfer Disclosure Statement Law – Overview. California Associate of Realtors. 2018. https://www.car.org/-/media/CAR/Documents/Transaction-Center/PDF/QUICK-GUIDES/Quick-Guide—Transfer-Disclosure-Statement-Law—Overview.pdf

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