Bug bombs-or as they’re known more formally “total release foggers”-seem like a great idea. Just set off a presumably powerful (they’re called “bombs,” after all) device, leave for the afternoon, and return to a house cleared of all unwanted pests (other than in-laws).
In reality, though, they’re really not as effective as you’d think. There are not many circumstances where they will solve the problem you’re trying to solve, plus there are serious health and safety risks if you aren’t utterly scrupulous in following their directions.
First, what is a bug bomb?
A bug bomb is a canister of aerosol insecticide that gradually releases its contents upward in a mist to permeate as much as possible of the area in which it’s used. During this process, people (and pets) must vacate the area.
If you think of a bug bomb as roughly equivalent to standing in the middle of a room and spinning around in a circle while spraying insecticide upward and outward, you’ll maybe get a sense of both the (limited) effectiveness to expect, and some of the safety issues.
So let’s turn to the health and safety matters:
1. You don’t want to inhale insecticide, so take seriously the directions about not being present when the bug bomb is going off. Leave the premises for the specified number of hours. Return just long enough to open windows to air out the area, and then leave again for an hour or so. People have gotten very sick by hanging around part of the time while the bug bomb was spewing its contents, or returning too soon when there was still plenty of insecticide in the air.
2. Remember, you’re spraying insecticide all over the area. So you need to be meticulous about food, dishes, surfaces used for food preparation, children’s toys or anything a child might put in its mouth, bedding, etc. These items must be removed entirely, completely covered, or thoroughly washed after the bombing.
3. The contents of the bug bombs are flammable. They can and sometimes do explode when used improperly. (This is especially a risk when excessive bug bombs are used. Some people assume-wrongly-that however effective one bomb would be, if they set off four bombs in the same room at once, it would be four times as effective.) The flame of a pilot light can do it. Someone who has-unwisely-remained in the area while the bug bomb is going off and lights a match or lighter for his cigarette can do it. There’s even a small chance that a tiny spark from an electrical device like an air conditioner or refrigerator can do it. It sounds like an urban legend, but people have blown up their house or apartment with bug bombs.
Certainly these risks can be minimized, though not eliminated, by following the directions and taking sensible precautions. But is it worth even the lessened risk? Will bug bombs wipe out all the nasty creepy crawlies they’re designed to attack?
For the most part, no.
The bug bombs are sometimes marketed as good for getting deep into all the cracks and crevices and such in the house, but this is precisely what they don’t do. Think about how they work. The insecticide is spewed up into the air, and gradually floats down, settling in a thin layer over the floor and furniture and such in the room. A closet, say, even with the door open, is going to get very little of the insecticide. Half an inch into a crack in the wall in that closet is going to get even less, and several inches into that crack is going to get none whatsoever.
For many bugs, it’s incredibly easy to avoid this attack. Unless a bug stands around in the open letting the insecticide land on it, it is almost certain to survive.
The bug bombs can be effective against flying insects, and perhaps fleas in your carpet and that sort of thing, but any insect that can manage a strategic retreat into the walls or anywhere away from where the insecticide is slowly settling (cockroaches, for instance) will have little to worry about. They may not have read the instructions like you did, but they too will simply vacate the danger zone for a few hours and then return, healthy as ever.
So at best it may be worth trying a bug bomb under very limited circumstances: One, you are meticulous in following all safety directions, and, two, you use it in situations where the target pests have no apparent easy way to back off and wait out the bombing. Even then there’s no guarantee, and you may have to call in an exterminator or otherwise try some less crude method that’s more directed than spewing insecticide all over indiscriminately.