The short answer
- Fumigation and heat are whole-structure treatments: they should eliminate all drywood termite infestations at once, including hidden ones. Localized treatments can't guarantee that.[2][4]
- Fumigation won't fix subterranean termites, because most of the colony lives in nests near or below ground.[3][4]
- Everyone, including pets and houseplants, must leave for several days while the house is fumigated and aerated.[2][1][4][5]
- Get at least three inspection reports before deciding, and ask whether the fumigation will be monitored.[2]
- Don't go back in for any reason until the applicator has tested the air and posted a notice on the house saying it is safe to re-enter.[1][4][5]
If someone may be poisoned
- If, within 24 hours after the house is reopened, anyone has headaches, dizziness, nausea, watery eyes, coughing, nose or throat irritation, shortness of breath, double vision, unusual drowsiness, weakness or tremors, leave the house. Call a doctor or Poison Control at 1-800-222-1222, and tell the fumigation company.[4][5][8]
Do you need to tent?
Drywood termite infestations are hard to find and their extent is hard to judge, so inspection is best done by a professional. Do-it-yourself treatment isn't recommended, and the products needed aren't available to homeowners.[2]
Whole-structure treatments treat every infestation, accessible or not, at the same time. Localized or spot treatments cover a board or small group of boards, and you can never be sure all infestations were treated.[2]
California's Structural Pest Control Board puts it the same way: fumigation is not always required for drywood termites or wood-boring beetles. If only a small area is infested, a local treatment may be used, but it will not wipe out hidden infestations elsewhere in the building. Fumigation and whole-house heat are the only two whole-house methods; electrical, microwave and liquid nitrogen treatments are spot treatments, not alternatives to fumigation.[4]
- Fumigation with sulfuryl fluoride kills drywood termites within several days and is highly effective if applied correctly. Monitored fumigation, with gas-monitoring lines inside the structure, has the highest success rate; unmonitored jobs may fail.[2]
- Heat is the nonchemical whole-structure option: all wood is heated to at least 120°F and held there for at least 33 minutes. You're out for hours rather than days, but large beams and spots over concrete or tile can be hard to heat, and heat-sensitive items can be damaged.[2]
- Neither fumigation nor heat leaves residual protection; preventive treatments can be applied afterward.[2]
- Localized options include drill-and-inject insecticides, microwaves, electrocution and wood replacement; all depend on finding every infestation, and home-use products are not effective.[2]
What happens during fumigation
- The structure is sealed with a tarp, secured, and posted with warning signs.[1]
- A house can be sealed in two ways: wrapped with plastic, tape or similar materials, or covered with a tent of vinyl-coated nylon tarps.[4]
- Sulfuryl fluoride is colorless, odorless and highly toxic, so chloropicrin, a strong irritant, is commonly added as a warning agent.[1][6][7]
- The warning agent goes in first, before the sulfuryl fluoride, and makes eyes smart and water and has a sharp smell. EPA requires it in home fumigations; Florida requires it as well.[6][5]
- Every outside door gets a second lock that only the fumigation company can open, so no one, the owner included, can get in. Warning signs go up at every entrance (California) or on all sides of the structure (Florida).[4][5]
- How long it takes varies from six hours to one week, depending on the pest, the dose, the temperature, the size of the building and other factors. UC IPM says people, pets and plants have to leave for several days while the house is fumigated and then aired out.[4][2]
- After the tarp comes off, the house is aerated with fans, and the applicator monitors the air; you can't go back in until levels are confirmed at or below EPA's limit of 1 part per million.[1][5]
- Leftover residues are not expected to remain on surfaces.[1][5]
- Tarps dragged across roofs can damage them.[2]
- Under amended labels EPA approved in July 2024, home-use sulfuryl fluoride products require a fumigation log kept for each site and longer aeration times than before, and they point applicators to a list on EPA's website of the portable clearance devices that meet its performance standards.[6]
Notices, keys and neighbors
California and Florida both require paperwork before any gas is released. In California the company must have a fumigation notice signed by the occupants or their agent, naming the pest, the fumigant and its active ingredients, and stating that it is unsafe to return until a re-entry notice is posted. In Florida the company must give the owner the contract and give an adult in each home or unit a fact sheet for the specific fumigant.[4][5]
Tell the company about anything that connects your home to the building next door, such as shared construction, conduits, drains or central vacuum lines. California requires the company to ask, and Florida requires extra precautions for connected buildings.[4][5]
The applicator will usually ask for a key, so they can check that no people or pets are left inside and get in quickly in an emergency.[5]
If a neighbor is being fumigated, there is no set minimum distance between a tented building and the one next to it. Any enclosed space being fumigated has to be made reasonably gas-tight, and you can ask the applicator any questions you have.[5]
How to prepare
Your pest control company will give you detailed instructions. Preparation may include these steps:[1][4][5]
- Tell your neighbors, and ask them to keep children and pets away until reentry is allowed.[1]
- Remove all people, pets, fish, reptiles and houseplants.[1][4]
- That includes fish, and seeds and bulbs you plan to plant.[4][1]
- Remove or double-bag all food, animal feed, tobacco and medications that aren't in plastic, glass or metal packaging with the original airtight seal intact, including what's in the refrigerator and freezer. The applicator usually provides special bags.[1][4][5]
- Take waterproof covers off mattresses and pillows so gas doesn't get trapped.[1]
- Open all inside doors and drawers, including attics, closets, cabinets, chests and appliances such as the dishwasher and microwave.[1][5]
- Leave dresser drawers partly open and set the lids of plastic storage boxes ajar or take them off.[5]
- Some household items can hold the gas and let it out after the house is cleared. California public-health researchers list mattresses with air bladders, inflatable toys, scuba buoyancy vests and neoprene wetsuits. Ask your applicator how to handle anything like that before the fumigation.[8][4]
- Unplug or turn off electric heating elements and automatic appliance controls, and put out pilot lights and any open flames.[1]
- Outside, trim shrubs back so the tarps fit, and make sure decks and fence posts are separated from the house so the tarps can seal.[5]
Re-entry: how you know it's safe
- The applicator has to aerate the house and check each room with gas detection equipment before anyone moves back in. The limit is 1 part per million of sulfuryl fluoride.[5][1][8]
- When the house passes, a re-entry notice is posted. In Florida it goes on every entrance; in California it gives the date and time the building was released and the company's name, license number and phone number, and it names the fumigant used. If you don't see the notice, don't go in; call the company.[5][4]
- If you notice eye irritation, tearing or a sharp smell after you return, leave and ask the applicator to come back and check that the house was properly aired out and cleared.[5]
Is any gas left afterward?
Sources disagree on how fast the gas is gone. NPIC says leftover residues are not expected on surfaces, and Florida's agriculture department says the gas dissipates during aeration and leaves no residue on dishes, clothing or furniture.[1][5]
A 2019 article by California Department of Public Health staff found that illness after home fumigation still occurs. Between 2003 and 2014, California investigated 59 incidents of sulfuryl fluoride illness after structural fumigation. In chamber tests the gas came back out of some household materials, such as polyester fiber and polystyrene, for up to 40 days, and wall voids, outlets, crawl spaces, attics and cabinets can trap it. The authors called for longer aeration times and closer checks on clearance devices, and EPA has since lengthened the required aeration times.[8][6]
After you move back in
- Drywood termites can stay alive for up to a week after getting a lethal dose. Pellets and dust left in old tunnels can keep showing up, and that doesn't mean the fumigation failed. If you have questions about whether it worked, contact the company.[4]
- Spiders, cockroaches and other household pests can survive a fumigation, and you may see more ants for a while. The gas leaves no residual protection, so termites and other pests can come back later.[4][2]
- In California, the company must permanently attach a tag in the attic or in a subarea such as the garage, giving the company name, the date and the fumigant used. That has been required since 1961, and it's how a later owner can tell the house was fumigated.[4]
Common questions
- How long will we be out of the house?
- California's pest control board says a fumigation can take from six hours to one week. UC IPM says people, pets and plants have to stay out for several days, depending on the size of the building and how much gas is used. Your company sets the schedule, and you stay out until the re-entry notice is posted.[4][2][5]
- Do I need to rewash dishes and clothes after fumigation?
- Florida's agriculture department says no: the gas dissipates during aeration and leaves no residue on dishes, clothing or furniture, and NPIC says residues are not expected on surfaces. Food and medicine are a different matter; they must be removed or sealed in the special bags before the fumigation.[5][1]
- Will tenting get rid of subterranean termites too?
- No. Most of a subterranean termite colony lives in the soil, in nests near or below ground, so those termites need a separate treatment.[3][4]
Sources
- National Pesticide Information Center, “Structural Fumigation.” npic.orst.edu/pest/fumigation.html (accessed 2026-11-10)
- University of California Statewide IPM Program, “Drywood Termites (Pest Notes, Home and Landscape).” ipm.ucanr.edu/home-and-landscape/drywood-termites/ (accessed 2026-10-06)
- University of California Statewide IPM Program, “Subterranean and Other Termites (Pest Notes, Home and Landscape).” ipm.ucanr.edu/home-and-landscape/subterranean-and-other-termites/ (accessed 2026-10-06)
- California Structural Pest Control Board, “Questions and Answers Regarding Structural Fumigation for Pest Control (18_334, revised 03/2019).” www.pestboard.ca.gov/forms/fumigate.pdf (accessed 2026-11-10)
- Florida Department of Agriculture and Consumer Services, “Structural Fumigation FAQ.” www.fdacs.gov/Consumer-Resources/Health-and-Safety/Protect-Your-Home-from-Pests/Florida-Structural-Fumigation-Information/Structural-Fumigation-FAQ (accessed 2026-11-10)
- U.S. Environmental Protection Agency, “Sulfuryl Fluoride.” www.epa.gov/ingredients-used-pesticide-products/sulfuryl-fluoride (accessed 2026-11-10)
- CDC / National Institute for Occupational Safety and Health, “NIOSH Pocket Guide to Chemical Hazards: Sulfuryl fluoride.” www.cdc.gov/niosh/npg/npgd0581.html (accessed 2026-11-10)
- International Journal of Environmental Research and Public Health (California Department of Public Health authors), “Barreau T, Hoshiko S, Kreutzer R, Smorodinsky S, Talarico J. Sulfuryl Fluoride Poisonings in Structural Fumigation, a Highly Regulated Industry: Potential Causes and Solutions. Int J Environ Res Public Health 2019;16(11):2026.” pmc.ncbi.nlm.nih.gov/articles/PMC6603922/ (accessed 2026-11-10)