When I am asked to identify an indoor insect or asked how to control one, the person will sometimes tell me they used an insect fogger. Over-the-counter foggers are usually not effective in controlling most household insects and they can be dangerous.
Following is an article from the September 2013 Nebline edition, a newsletter printed by the Lancaster County Extension office. The article was written by Extension Educator Barb Ogg, and I am using it with her permission.
Over-the-counter insect foggers (i.e., “bug bombs”) are usually purchased by consumers because they seem to be an inexpensive and convenient way of killing insects. Unfortunately, they are not always effective against those pests people are trying to kill. To understand why they are not very effective, it is helpful to understand what a fogger actually is.
An insect fogger is a total-release aerosol. Active ingredients are pyrethroid and/or pyrethrin insecticides. There is often a synergist in the formulation, like piperonyl butoxide, which is used to stabilize the active ingredients which tend not to last very long. Most of the fogger formulation (usually more than 99 percent) is a petroleum distillate carrier.
The fogger is not a gas, but a liquid aerosol mist. When someone sets off the fogger, the insecticide mist is released into the air. Eventually, the insecticide residue falls on all horizontal surfaces: kitchen countertops, floors, tables, chairs and beds.
This mist does not penetrate cracks, crevices and other harborages where most pests like cockroaches, silverfish, bed bugs and flea larvae live. Consequently, over-the-counter foggers will not control these pests. Foggers will only be effective against exposed insects, those insects flying around or exposed on walls. At the Extension office, we rarely encounter pest situations where foggers will solve the pest problem.
Dr. Susan Jones, Ohio State University entomologist, conducted a recent study which showed over-the-counter foggers had little effect on most field collected strains of bed bugs, even when directly exposed to the insecticide fog for two hours.
She tested three readily-available products: Hotshot Bedbug and Flea Fogger, Spectracide Bug Stop Indoor Fogger and Eliminator Indoor Fogger. Even though these products claim “kills on contact,” she found bed bugs were unaffected and even remained unharmed five to seven days after the study. Dr. Jones concluded bed bugs hiding in their normal harborages (i.e., cracks and crevices) would be completely unaffected by these foggers.
Every year or so, we hear about consumers who use these foggers in such a way they truly become a “bug bomb.” They do not read or understand the label directions and use too many foggers at one time. If they fail to turn off the pilot light on their water heater or gas stove, the flammable petroleum distillates can cause an explosion.
The latest bug “bomb” explosion was in New York City. On July 12, 2013, the New York Times reported a woman set off 20 foggers in her apartment. The next day, she set off 20 more in another room. The blast was so powerful, it blew out the back wall of the apartment, causing a fire which left 12 people injured and partially collapsing the building.
A number of entomologists have begun to question why these products are available for purchase, since they aren’t usually effective and are a potential hazard. Even when used according to the label directions, pesticide residues from foggers remain on horizontal surfaces where children play, people sleep and food is prepared.
To watch a short video describing her research, check out a Pest Control Technology interview with Susan Jones at www.pctonline.com/Jones-bed-bug-bugbombs.aspx r o l specific and the for Nebraska at free edu/
Kelly Feehan is a UNL extension educator-horticulture. She can be reached at (402) 563-4901 or by email at firstname.lastname@example.org.