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Pesticide safety

Why bug bombs don't work well

Foggers spray a mist that settles on exposed surfaces; they don't reach the voids, cracks and crevices where pests such as cockroaches and bed bugs hide.[1]

The short answer

  • For bed bugs, over-the-counter foggers have been shown to be ineffective and potentially harmful to residents.[2]
  • Some fogger ingredients repel pests, driving them deeper into hiding.[1]
  • Fogger contents can catch fire and explode; using more than the label says increases risk without improving control.[1]
  • CDC identified 3,222 fogger-related illnesses and injuries in 10 states from 2007 to 2015; the most common causes were not leaving during the application and going back in too early.[3]
  • In a North Carolina State study of cockroach-infested homes, foggers did not reduce German cockroach numbers, while gel baits did, and the foggers left pesticide residues across kitchen surfaces.[6]

What the research found

Researchers have put store-bought foggers to the test against the two pests people most often bomb for, and both studies came out the same way.[5][6]

  • Bed bugs (Ohio State, 2012): field-collected bed bugs showed little if any harm after 2 hours of direct exposure to the mist from three over-the-counter foggers. Even a lab strain that is easily killed by pyrethroids survived when it was covered by a thin layer of cloth. The authors concluded foggers should not be recommended for bed bugs, because many bed bugs are resistant to pyrethroids and the mist barely gets into the places they hide.[5]
  • German cockroaches (NC State, 2019): in infested homes, 20 were treated with one of four fogger products and 10 with gel baits. The foggers failed to reduce cockroach numbers; the similarly priced baits caused significant declines.[6]
  • Why the roaches survived: cockroaches collected from the homes where foggers failed were 202 times more resistant to cypermethrin, a common fogger ingredient, than a susceptible lab strain, and more than 96% carried at least one copy of a gene mutation tied to pyrethroid resistance. The same foggers killed susceptible cockroaches placed in the homes for comparison.[7]
  • Where the pesticide goes: in the NC State homes, pesticide residues on horizontal kitchen surfaces after a fogger averaged 603 times the level before treatment, with a median increase of 85 times.[6]
  • A University of California, Riverside study of empty homes assigned a fogger in a small room a horizontal distribution factor of 100%, compared with 15% for a crack-and-crevice spray and 2% for a spot spray. In other words, a fogger's spray ends up spread across open surfaces rather than aimed at hiding spots.[8]

Why the mist misses

A fogger releases its whole can upward into the room. The droplets hang in the air, then settle onto floors, counters and other surfaces. Very little gets into the cracks, voids and other hidden places where cockroaches, ants, bed bugs and most other household pests spend most of their time.[10][11]

  • Pyrethrins, a common fogger ingredient, are somewhat effective against exposed flying insects such as house flies, but Kentucky says they seldom kill cockroaches, ants, bed bugs, spiders, silverfish and other crawling pests.[10]
  • Fogger ingredients tend to repel insects, so they scatter deeper into walls and crevices. UC IPM and Penn State say foggers may disperse cockroaches to other areas without killing them.[10][1][15][20]
  • Many pests already resist the chemicals foggers use. NPIC lists bed bugs among pests that can be resistant, and resistance is a main reason foggers failed against German cockroaches in the NC State work.[1][7]
  • EPA notes that a fogger's pesticide has to touch the pest to kill it, so bed bugs in cracks and crevices the mist doesn't reach will not be killed.[22]
  • Texas A&M says bug bombs work on flying insects and insects on exposed surfaces but generally do not eliminate cockroaches; Rutgers calls them not effective and says to avoid them.[18][19]

Illnesses, fires and explosions

Foggers contain flammable aerosol propellants that can cause fires or explosions. CDC notes media reports of injuries and property damage from explosions when foggers were set off near ignition sources such as gas pilot lights and appliances that cycle on and off, like air conditioners and refrigerators.[4]

Kentucky reports house fires when people forgot to put out pilot lights on stoves, furnaces and other appliances, and fires set off by a lit cigarette.[10][11]

  • 2001 to 2006: CDC counted 466 fogger-related illnesses or injuries in eight states. Common causes were not getting out before the fogger went off, going back in too soon, using too many foggers for the space, and not warning people nearby.[4]
  • 2007 to 2015: CDC identified 3,222 cases in 10 states. 92% happened in private homes. Breathing problems (cough, upper airway irritation, shortness of breath) and stomach symptoms (nausea, vomiting, cramps) were most common. 78% were low severity, 21% moderate and 0.7% high, and four people died.[3]
  • About 4% of the 2007 to 2015 cases happened when children under 13 set off a fogger.[3]
  • People who went back in early often did it to turn off a smoke alarm or get a pet or forgotten item. Some were exposed while going in to open windows, and some were sprayed in the face when the nozzle misfired or pointed the wrong way.[3]
  • In one CDC case, a neighbor set off three foggers in a converted house where all the apartments shared one ventilation system; a tenant who had not been told went to the emergency department with headache, shortness of breath, nausea and burning eyes.[4]
  • EPA required clearer labels on foggers made after September 2012: leave the premises for at least 2 hours, then air it out for another 2 hours or until there's no odor, and don't use more foggers than needed. Illnesses from using too many foggers then fell, but the overall illness rate did not drop through 2015.[3]
  • People with asthma had more moderate or severe illnesses in CDC's data. NPIC says foggers may pose more risk to children and people with asthma, and Kentucky says people with asthma can react severely to pyrethrins used indoors.[3][1][10]
  • Residue doesn't stay put: a University of California, Riverside test in an enclosure found a fogger's pyrethroid deposited on surfaces could be picked up by cloth and washed into wastewater through cleaning and laundry.[9]

What to do instead, by pest

Deter pests first: clean, declutter and remove the food, water and shelter they need.[1]

Use methods that reach hiding places, such as baits placed where cockroaches harbor and the nonchemical tactics used for bed bugs.[2][1]

  • Cockroaches: use gel baits and bait stations where roaches hide, and boric acid dust in hard-to-reach voids. Kentucky notes baits have almost no odor and usually don't require emptying cabinets. Start with the cockroach router guide.[6][11][19]
  • Bed bugs: UC IPM, Kentucky, NPIC and EPA all say foggers aren't the answer. Kentucky also warns against bleach, alcohol and cigarette lighters, which are ineffective and can start fires. Use heat, laundering, mattress encasements, targeted crack-and-crevice treatments, or an experienced professional.[2][13][24][23]
  • Fleas: Kentucky says foggers seldom work on fleas because the spray goes up and misses where larvae develop. UC IPM says room foggers don't match direct sprays unless they contain the growth regulator methoprene or pyriproxyfen. NPIC recommends vacuuming, washing bedding in hot water and targeted treatments with insect growth regulators, and asking your veterinarian about flea control for your pet.[12][16][25]
  • Ants, spiders, silverfish and other crawling pests: apply sprays, baits or dusts directly where the pests hide. Kentucky says targeted treatments work better against all kinds of household pests, and that sometimes a fly swatter, vacuum or door sweep is all you need. UC IPM does not recommend foggers for silverfish.[10][17]

Where a fogger might make sense

Kentucky names one of the few uses: cluster flies, paper wasps and similar insects in attics, outbuildings or other cluttered, hard-to-reach spaces. It says foggers should be considered for spiders only in inaccessible areas such as attics.[10][14]

Even there, Penn State says a pyrethrum fogger will kill cluster flies gathered in an attic but won't stop more from coming out of wall voids, so it isn't a long-term fix.[21]

If you use one

  • Check that your pest is on the label, and use no more foggers than the label allows for the space.[1]
  • Never use them in small enclosed spaces such as closets, cabinets or most vehicles.[1]
  • Turn off pilot lights, keep foggers away from flames, and unplug appliances.[1]
  • Remove toys, pet items, food, dishes and plants; leave immediately; stay out as long as the label says or longer; then open windows and use fans.[1]
  • Clean surfaces children or food will touch, wearing protective clothing.[1]
  • Check that the fogger's label lists your pest; not all are labeled for bed bugs, and EPA says a fogger should not be your only bed bug method.[22][23]
  • Warn people who might come in, and post door tags or signs. In apartments, tell neighbors who share walls or ventilation.[1][4]
  • If you have a fish tank, cover it and turn off its pumps while the fogger runs.[26]
  • Cover recently treated furniture with a sheet or blanket before setting down young children.[1]
  • If someone is exposed, move them to fresh air and call a doctor or Poison Control at 800-222-1222.[1]

Common questions

Do bug bombs kill bed bugs?
Not reliably. In Ohio State tests, bed bugs survived 2 hours of fogger mist with little or no harm, especially when they could hide. UC IPM, Kentucky and NPIC all say foggers don't work for bed bugs.[5][2][13][24]
Do foggers work on cockroaches?
In NC State's home study they didn't reduce German cockroach numbers, partly because the roaches were highly resistant to the pyrethroid in the foggers. Gel baits did work.[6][7]
Will a bug bomb get rid of fleas?
Usually not. Kentucky says foggers seldom control fleas because they don't reach where larvae develop, and UC IPM says a fogger only approaches a direct spray if it contains methoprene or pyriproxyfen.[12][16]
How long do I stay out after setting off a fogger?
As long as the label says, or longer. Labels made after September 2012 tell you to leave the premises for at least 2 hours and then ventilate for another 2 hours or until there's no odor; CDC found some people still got sick after following that.[1][3]
Can a bug bomb really explode?
Yes. The propellants are flammable, and pilot lights, appliances that switch on and off, open flames or a lit cigarette can ignite them. Using more foggers than the label allows raises the risk.[4][10][22]

Sources

  1. National Pesticide Information Center, “Total Release Foggers.” www.npic.orst.edu/ingred/ptype/fogger.html (accessed 2026-10-06)
  2. University of California Statewide IPM Program, “Pest Notes: Bed Bugs, Publication 7454 (May 2013).” ipm.ucanr.edu/legacy_assets/PDF/PESTNOTES/pnbedbugs.pdf (accessed 2026-10-06)
  3. U.S. Centers for Disease Control and Prevention, “Acute Illnesses and Injuries Related to Total Release Foggers, 10 States, 2007-2015. MMWR 67(4).” www.cdc.gov/mmwr/volumes/67/wr/mm6704a4.htm (accessed 2026-10-06)
  4. U.S. Centers for Disease Control and Prevention, “Illnesses and Injuries Related to Total Release Foggers, Eight States, 2001-2006. MMWR 57(41).” www.cdc.gov/mmwr/preview/mmwrhtml/mm5741a3.htm (accessed 2026-11-10)
  5. Journal of Economic Entomology (PubMed 22812136), “Jones SC, Bryant JL. Ineffectiveness of over-the-counter total-release foggers against the bed bug (Heteroptera: Cimicidae). J Econ Entomol 2012;105(3):957-63.” pubmed.ncbi.nlm.nih.gov/22812136/ (accessed 2026-11-10)
  6. BMC Public Health (PubMed 30686267), “DeVries ZC et al. Exposure risks and ineffectiveness of total release foggers (TRFs) used for cockroach control in residential settings. BMC Public Health 2019;19:96.” pubmed.ncbi.nlm.nih.gov/30686267/ (accessed 2026-11-10)
  7. Journal of Economic Entomology (PubMed 31121031), “DeVries ZC et al. Pervasive resistance to pyrethroids in German cockroaches related to lack of efficacy of total release foggers. J Econ Entomol 2019;112(5):2295-2301.” pubmed.ncbi.nlm.nih.gov/31121031/ (accessed 2026-11-10)
  8. Regulatory Toxicology and Pharmacology (PubMed 20472011), “Keenan JJ et al. Deposition and spatial distribution of insecticides following fogger, perimeter sprays, spot sprays, and crack-and-crevice applications. Regul Toxicol Pharmacol 2010;58(2):189-95.” pubmed.ncbi.nlm.nih.gov/20472011/ (accessed 2026-11-10)
  9. Science of the Total Environment (PubMed 35842158), “Dery M et al. Wash-off potential of pyrethroids after use of total release fogger products. Sci Total Environ 2022;847:157340.” pubmed.ncbi.nlm.nih.gov/35842158/ (accessed 2026-11-10)
  10. University of Kentucky Entomology, “ENTFACT-643: Limitations of Home Insect Foggers (Bug Bombs).” entomology.ca.uky.edu/ef643 (accessed 2026-11-10)
  11. University of Kentucky Entomology, “ENTFACT-614: Cockroach Elimination in Homes and Apartments.” entomology.mgcafe.uky.edu/ef614 (accessed 2026-11-10)
  12. University of Kentucky Entomology, “ENTFACT-602: Flea Control and Prevention.” entomology.mgcafe.uky.edu/ef602 (accessed 2026-11-10)
  13. University of Kentucky Entomology, “ENTFACT-636: Bed Bugs.” entomology.mgcafe.uky.edu/ef636 (accessed 2026-11-10)
  14. University of Kentucky Entomology, “Eliminating Spiders Around Homes and Buildings (ENTFACT-623).” entomology.mgcafe.uky.edu/ef623 (accessed 2026-11-10)
  15. University of California Statewide IPM Program, “Pest Notes: Cockroaches, Publication 7467 (revised December 2019).” ipm.ucanr.edu/legacy_assets/PDF/PESTNOTES/pncockroaches.pdf (accessed 2026-11-10)
  16. University of California Statewide IPM Program, “Pest Notes: Fleas (Home and Landscape).” ipm.ucanr.edu/home-and-landscape/fleas/ (accessed 2026-11-10)
  17. UC Statewide Integrated Pest Management Program, “Silverfish and Firebrats.” ipm.ucanr.edu/home-and-landscape/silverfish-and-firebrats/ (accessed 2026-11-10)
  18. Texas A&M AgriLife Extension, “Cockroaches: Biology and Management, ENTO-037.” extensionentomology.tamu.edu/wp-content/uploads/sites/3/2017/12/Cockroach-Biol-and-Mngmt_ENTO-037_2017.pdf (accessed 2026-11-10)
  19. Rutgers Cooperative Extension, “FS1327: Cockroach Species in New Jersey and Their Control Strategies.” extension.rutgers.edu/fs1327 (accessed 2026-11-10)
  20. Penn State Extension, “German Cockroaches.” extension.psu.edu/german-cockroaches (accessed 2026-11-10)
  21. Penn State Extension, “Cluster Flies.” extension.psu.edu/cluster-flies (accessed 2026-11-10)
  22. U.S. Environmental Protection Agency, “Should I Use a Fogger?.” www.epa.gov/bedbugs/should-i-use-fogger (accessed 2026-11-10)
  23. U.S. Environmental Protection Agency, “Do-it-yourself Bed Bug Control.” www.epa.gov/bedbugs/do-it-yourself-bed-bug-control (accessed 2026-11-10)
  24. National Pesticide Information Center (Oregon State University and U.S. EPA), “Bed Bugs.” npic.orst.edu/pest/bedbug.html (accessed 2026-11-10)
  25. National Pesticide Information Center, “Fleas.” npic.orst.edu/pest/flea.html (accessed 2026-11-10)
  26. National Pesticide Information Center, “Pesticide Use Around Pets.” npic.orst.edu/health/pets.html (accessed 2026-11-10)

Updated 2026-11-10. General information, not medical or veterinary advice. Built from sourced records. Spot an error? Tell us.