Bug bombs don't work, says NC State

It might feel satisfying to "bomb" insects, but research shows that it doesn't work

Total release foggers, better known as "bug bombs" are ineffective, according to research from North Carolina State University
Feburary 8, 2018 

Bug bombs don't reach pests

Bad news, folks. Bug bombs don’t work, according to research from North Carolina State University. Bug bombs —or total release foggers—spray a mist of pesticides into a room. The mist settles on surfaces, furniture and appliances. In other words, places most often used by humans and pets, not bugs.

Common pests like cockroaches and bed bugs frequent the undersides of surfaces, on walls or the recesses of a cupboard—spots the fogger doesn’t penetrate.

“I’ve been seeing these foggers in home for decades, but there’s incredibly little research on them,” said Coby Schal, Ph.D., one of the researchers on the team from NC State. “Professionals don’t use these products, it’s only consumers that buy them.”

Researchers tested the effectiveness of widely-available bug bomb varieties on 20 apartments infested with German cockroaches. Some apartments were heavily infested, others less so. But in all cases, the bug bombs did not wipe out the cockroaches—not even close. Two weeks after “bombing,” populations levels showed no change. One month out? The same amount of cockroach infestation remained and sometimes increased. 

Cockroaches have developed resistance to insecticide

Even when researchers trapped the cockroaches in cages and put them right in front of the bug bomb, the spray failed to kill all the roaches. Schal said that’s because most cockroach populations have become resistant to pyrethroids, the insecticide used in bug bombs.

“The cockroach resistance level is about 200-fold,” said Schal. “So you’d need 200-fold the amount of the current lethal dose of these insecticides to kill them.”

Health impacts of insecticides

Not only did the bug bombs fail, but they left a film of pesticides covering the apartment. Those chemicals can make people sick, especially when the bug bombs aren’t used properly. In 2018, the CDC published a 10-state study of bug-bomb related illnesses. They found more than 3,200 incidents of illness over an 8-year period. The illnesses included respiratory, gastrointestinal, cardiac, neurologic, and eye and skin problems.

According to the study, many of those incidents happened when people didn’t ventilate the room after bombing, or came back too early. And those are just the acute, or immediate, illnesses. There are a host of studies linking insecticides to illnesses as wide-ranging as fertility issues and cancer.

Roach motels for the win

So bug bombs are out, but what if the bugs remain? The team from NC State found that baited cockroach traps, better known as roach motels, work well. They lure cockroaches in with insecticide-laced food.

“In toxicology we have this saying: 'the dose makes the poison,’ ” said Schal. “Those cockroach traps have a high dose of insecticide, but they’re placed in spots where people won’t be exposed to them.”

Schal said that in lots of cases, it’s low-income apartments that have problems with insect infestation, and generally tenants can’t afford professional treatment, which is why they turn to bug bombs. Researchers found that not only are traps more effective, they are about the same price as bug bombs, without all the additional exposure.

“With the bug bombs, the dose is massive, the exposure is massive. Kids crawl on the floor, pets walk over it and then join us in bed,” said Schal. “I call it environmentally irresponsible.”

The research is published in the journal BMC Public Health.

 - Rossie Izlar

Rossie Izlar is a digital producer on the UNC-TV Science team.