How to get smoke smell out of a house: what works and what EPA warns

Why does smoke smell linger after a fire?

Smoke smell lingers because the source is still in the house. The IICRC, RIA and CIRI Technical Guide for Wildfire Restoration (December 2025) splits smoke odor into two groups. Light, gaseous compounds such as benzene and formaldehyde tend to clear quickly with ventilation. Heavier compounds stick to soot, ash and surfaces like carpet and drywall, and can off-gas for hours to weeks or months.

That is why airing out works for a day and then the smell comes back. Heat makes it worse. A 2019 Restoration & Remediation (R&R) article explains that fire heat opens surface pores, letting odor soak deep into materials, and the draft IICRC S760 standard notes odors often show up more strongly with warmth. No machine fixes residue it cannot reach. Start with our smoke damage cleanup guide.

What is the right order for removing smoke odor?

Every source we reviewed puts cleaning first and machines last. A 2017 R&R article says removing smoke and fire residues and their sources “should be your first priority.” The draft IICRC S760 standard calls fogging and sealers supplemental steps used when odor remains after cleaning.

1. Remove the source. Tear out charred materials and throw away items that cannot be cleaned, after you photograph them for your insurer.
2. Clean surfaces. HEPA vacuum, then damp clean with detergent, ceiling to floor.
3. Clean soft goods. Launder, dry-clean or replace clothing, bedding and curtains. Upholstered furniture and mattresses often need professional cleaning.
4. Clean the HVAC system. The wildfire guide calls for duct cleaning to NADCA standards and new filters rated MERV 11 or higher.
5. Ventilate and filter. Open windows when weather allows and run filtered air.
6. Deodorize what remains. Fogging, hydroxyl or ozone, done by a pro.
7. Seal last. Prime and repaint only after cleaned surfaces no longer smell.

What can you do yourself?

The safest home tools are air and filtration. EPA’s Guide to Air Cleaners in the Home says that to filter gases you should choose a portable air cleaner with an activated carbon filter or another filter designed to remove gases, and that carbon filters can work when there is a large amount of carbon in the filter. A unit with both a HEPA filter and carbon handles particles and gases. EPA notes there is no widely used rating system for gas filtration, so the familiar CADR number covers particles only.

For fabrics, the Red Cross suggests a cold wash with your usual detergent plus one tablespoon of pure vanilla extract, or a measured trisodium phosphate solution for items that can be bleached. Keep the house dry while you work, since damp materials hold odor and can grow mold. A dehumidifier helps; see our guide to the best dehumidifier for mold.

Skip consumer ozone machines and scented sprays. EPA’s air cleaner guide says to avoid portable air cleaners and HVAC filters that intentionally produce ozone, because ozone is a lung irritant.

Ozone vs hydroxyl vs thermal fogging: how do they compare?

These three methods are professional tools. None replaces cleaning.

What does EPA say about ozone generators?

EPA’s page “Ozone Generators that are Sold as Air Cleaners,” last updated February 19, 2026, is the clearest federal guidance. Its key points:

• Safe levels do little. EPA says available scientific evidence shows that at concentrations that do not exceed public health standards, ozone has little potential to remove indoor air contaminants.
• Odor claims are weak. EPA says ozone at those levels is not effective at removing many odor-causing chemicals, and that some experiments suggest ozone masks odor rather than removing it.
• It harms lungs. EPA says that when inhaled, ozone can damage the lungs, and relatively low amounts can cause chest pain, coughing, shortness of breath and throat irritation.
• It makes new chemicals. In one study EPA cites, ozone reacting with carpet chemicals produced aldehydes, and total organic chemicals in the air rose.
• Empty spaces only. EPA notes high concentrations are sometimes used in unoccupied spaces, with fire restoration as an example, but conditions should be controlled so no person or pet is exposed, and little is known about byproducts left behind.

EPA’s air cleaner guide adds that no federal government agency has approved ozone generators for use in occupied spaces. The California Air Resources Board (CARB) strongly advises against using them where people or animals are present, and warns ozone can deaden your sense of smell, which can hide both the odor and the ozone itself.

When should you hire a pro for smoke odor?

Hire a pro when the smell survives cleaning and ventilation, when it comes back on warm days, or when smoke went through the ducts. Those are signs residue is in places you cannot reach, such as wall cavities, insulation or the attic. The IICRC Odor Control Technician (OCT) certification covers odor sources, detection and control equipment, including odors from fire and smoke.

Before any machine runs, ask for a written plan: which rooms, which method, how long you must stay out, what will be removed or covered, and how the job will be checked. The wildfire guide describes a final walkthrough with an odor check. Our fire damage restoration process page shows where odor control fits in the larger job.

What does smoke odor removal cost, and will insurance pay?

Angi (updated September 25, 2026) lists thermal fogging at $200 to $600 and ozone treatment at $400 to $800. HomeGuide (November 17, 2025) lists ozone at $300 to $700. Our fire damage restoration cost page compares the full range of published figures.

Whether insurance pays depends on your policy and the cause of the smoke. A sudden fire is different from years of cigarette smoke. Check your declarations page and policy, and ask your insurer before work begins. If you disagree with a decision, ask your state insurance department, a licensed public adjuster or an attorney. More guides are on the fire and smoke hub.