What’s in a bug repellent?


Bug repellents can be a real saviour when you’re being eaten alive by soul-sucking mosquitoes while venturing outdoors to enjoy the warm temperatures this summer. But have you ever stopped to consider what exactly is in that cloud of chemicals you’re spraying?

Technically, bug repellents are pesticides. Rest assured though, the Government of Canada requires all pesticides to be registered before they’re sold in Canada. This means the pesticide must go through a science-based risk assessment to ensure the product works effectively and meets both health and environmental standards.

DEET is commonly the active ingredient in many bug sprays. The American CDC has said repellents with DEET offer the best protection from mosquito bites. However, if not used properly, DEET can be harmful. So, it’s important to use repellents as directed.

DEET is offered in different concentrations. Health Canada has proper application guidelines for different concentrations on people of different ages. Corey Jefferies, a Primary Care Network pharmacist, said using too much DEET can cause some skin reactions like rashes, swelling, inflammation or blistering – but that’s usually with high concentrations being used more frequently than recommended.


The right concentrations of DEET for:

• Adults and children over 12 years old is up to 30 per cent

• Children aged two to 12 years old is up to 10 per cent (may be applied up to three times daily)

• Children aged six months to two years old is up to 10 per cent (should not be applied more than once daily).


For children under 12 years old, DEET should not be used on a daily basis for more than a month.

For infants under six months old, DEET should not be used at all. Use other bug aversion techniques, such as mosquito nets.


Higher concentrations of DEET don’t typically offer much more protection, although they may last longer before reapplication is needed.

“It depends on where you’re going, how long you‘ll be out and the level of mosquitoes in the area,” Jefferies said. “So, if you’re hiking and there’s lots of mosquitoes on the trails, using a higher percentage will be helpful because it’ll give you that longer lasting action.”

Jefferies said DEET does have solvent properties and has been known to dissolve plastic products. He said synthetic fabrics like nylon or rayon could be damaged by DEET, but natural fibres like cotton won’t see a problem.

“If you’re worried about the solvent properties in DEET, there are other bug sprays available containing different repellents that don’t have those properties,” he said.


Alternative bug repellents to DEET:

• Icaridin (shouldn’t be used on children under six months old)

• Soybean oil (no age restrictions)

• Citronella oil (shouldn’t be used on infants and toddlers)

• Essential oil mixtures such as lemon, eucalyptus, pine needle, geranium and camphor (shouldn’t be used on children under two years old)


While there are alternatives to DEET, Jefferies said he wouldn’t recommend people attempt to make their own concoctions because there’s room for human error when measuring out the ingredients.

“You could be overexposing yourself to whatever oil you’re using and whatever side effects are associated with that particular oil.”

Not all natural repellents will repel the same insects that DEET might, he added.

So when you’re searching for the right product for you and your family, Jefferies suggests choosing a product that has been reviewed by Health Canada. Look for products with a pest control product (PCP) registration number on the label.


Best practices for applying bug spray:

• Bug sprays can be applied lightly, you don’t need to douse yourself

• Spray in an open area, not in a confined space

• Do not allow children to apply bug sprays

• Do not apply to open wounds (increases the amount of product absorbed into the bloodstream)

• Do not apply to children’s hands (risk of accidental ingestion when fingers go near mouths)

• Apply only on exposed skin (a precaution to avoid overexposure to repellent agents)

• If using sunscreen and bug spray, apply sunscreen first and wait 15 minutes before applying bug spray (when immediately combined, sunscreen can be less effective)


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Jasmine Roy