For many years the go-to solution for DIY pest control was the bug bomb.  Got fleas? Get yourself a bug bomb.  Cockroaches in the kitchen?  Bug bomb! Most recently, it’s bed bugs.  See a bed bug? Reach for the bug bomb.

But do bug bombs (also known as total release aerosols) really work?  Not very well according to a recent paper was published last month in the Open Access journal BMC Public Health.  Researchers at North Carolina State University found that not only did bug bombs under-perform (not even killing cockroaches penned in open containers), they left residues on floors and counter-tops.

All homes in the study were infested with German cockroaches, the most common and difficult-to-control cockroach found in homes and restaurants in the U.S.  Twenty homes were treated according to label instructions with one of four total release aerosol products. Ten homes were treated with over-the-counter gel baits designed for cockroaches. Cockroaches used for the test included insecticide-susceptible, lab-reared cockroaches and wild cockroaches collected from the tested apartments.  Cockroaches were confined in open-topped containers and exposed to the fogs either on the apartment floor or in an open cupboard.

While the wimpy, lab-reared cockroaches exposed in open cages suffered 90-100% mortality, the tougher, “wild” cockroaches, similarly caged, suffered only 10-38% mortality. Keep in mind that unlike cockroaches in your kitchen, the caged cockroaches in this experiment could not escape exposure to insecticide fog.  In actual kitchens, cockroaches typically hide in protective crevices when they sense an irritating insecticide.

Researchers also counted “free-range” cockroaches in apartments treated both with foggers and baits during the test. In fogger-treated apartments there was no significant drop in these wild cockroach numbers two to four weeks after the kitchens were bombed.  In apartments treated with gel baits cockroach numbers dropped 70-95%.  In other words, the “bombs” bombed, and gel baits worked pretty well.

Gels outperformed the bug bombs in terms of safety as well. No insecticide residues were found on untreated surfaces in bait-treated apartments; but all fogger-treated apartments had detectable insecticide residues on horizontal surfaces (floors, counter-tops, inside cupboards) up to a month after treatment.  Admittedly, residues were low, and likely of little importance to human health; but foggers do have a record of causing health concerns in people when they are used improperly.  Common health concerns among people exposed to fogger contents include coughing, difficulty breathing, itchy throat, headaches and even nausea and vomiting.

Dr. Susan Jones at Ohio State University saw similar results in her studies with bed bugs and insecticide foggers a few years ago.  Wild bed bugs almost literally laughed at researchers setting off foggers only feet from their cages in that test.

The lesson?  We need to stop thinking about bug bombs as effective tools against any insect that hides in protected places (like cockroaches, bed bugs and fleas), and especially those insects like bed bugs and cockroaches that have developed some degree of resistance to the insecticides used in foggers.

Given these data, it makes little sense to keep wasting money on these old-fashioned, risky and ineffective insecticide devices, especially when there are good alternatives available, like cockroach gel baits. Maybe, when it comes to cockroach and bed bug control, it’s time to kill the bug bomb?