Non-toxic Control of Cockroaches

American Cockroach

Cockroaches do not cause disease, and they rarely cause household damage. They can cause human allergies, particularly among asthma sufferers. However, they are hated by people as a symbol of uncleanliness.

Substances toxic to humans should not be used to kill cockroaches indoors. Homes are tightly sealed, especially in winter, and the inside environment is not subject to natural environmental processes. Pesticides remain dangerous for much longer periods indoors than if they were applied outdoors. People living in houses treated with insecticide can experience severe health reactions to the chemical. Cockroaches are so common that they have the potential to reach any building at any time. Spraying can not solve the problem. Prevention of cockroach infestations is your best means of ensuring a cockroach free environment.

To control cockroaches in buildings:

  1. Remove their sources of food. Thoroughly wet-mop floors and baseboards, especially under rugs and furniture, behind appliances, and in cabinets, then clean future food spills up as soon as they occur. Vacuum regularly wherever cracker crumbs or dry pet foods might fall.
  2. Block their points of entry. Use a foam or silicone caulk to seal all holes through walls, ceiling or floor from areas that might be infested. Especially check water and drain pipes. A 2 mm crack is all they need.
  3. Kill those that remain. Put small piles (¼ teaspoon each is plenty) of household borax powder in places where children or pets can not reach them and they will stay dry, such as under the refrigerator. Borax, diatomaceous earth or silica aerogel with an attractant added are commercially available - they are effective and non-toxic. A temperature below +2C kills adult German cockroaches, and -5C kills their eggs as well - a freezer is thus an effective way of eliminating them from bags of pet food or bird seed. (Note that ultrasonic or "electronic" devices neither kill nor repel cockroaches.)

Don't expect instant results. Any place infested with cockroaches will also be infested with their eggs, so it takes at least a couple of weeks to get rid of all of them. That's another reason why the pesticides often used to kill them are so dangerous - they have to remain lethal for several weeks too.

See also Environment Canada's fact sheets on pest control.

Provided by the Health Dangers of Urban Use of Pesticides Working Group of the Region of Ottawa-Carleton, Ontario Canada. Approved by Regional government and by the Ottawa-Carleton Health Department. Please feel free to copy.