HealthLinkBC File #96, January 2013

Insect Repellents and DEET





What is insect repellent?

Insect repellent is a spray or liquid used to keep biting insects, such as mosquitoes, away from your skin and clothing. Some repellents are also helpful against ticks. Repellents work by discouraging insects from landing on and biting your skin.

Insect repellent should be used when you are outdoors to protect against insect bites, which can cause illnesses, including West Nile Virus (WNV). To protect against mosquito bites, the most effective insect repellents to use are those which contain the ingredient DEET.

For more information on tick bites, see HealthLinkBC File #01 Tick Bites and Diseases.

What is West Nile Virus?

West Nile Virus, also known as WNV, is a disease usually spread between birds by mosquitoes. Mosquitoes can become carriers of the virus after biting birds infected with the virus. It is possible for people, horses and other animals to become infected if they are bitten by a mosquito carrying the virus.

For more information on West Nile Virus, see HealthLinkBC File #88 West Nile Virus.

What is DEET?

DEET is the common name for N,N-diethyl-m-toluamide. DEET is the active ingredient in the most effective and widely used insect repellents. Different repellents have different amounts of DEET. Products with higher concentrations of DEET are not more effective, but they will last longer.

Is DEET safe?

Yes, products containing DEET are very safe when used according to the directions on the label. There is no evidence that DEET poses a risk to pregnant or breastfeeding mothers, however pregnant or breastfeeding women may wish to consider the use of non chemical methods as a first line of defense.

Guidelines for using repellents with DEET

Concentration of DEET
Protection Time
30%
6 hours
15%
5 hours
10%
3 hours
5%
2 hours

Protection times may be less than this if you are sweating, getting wet, or if the repellant is rubbed off your skin.

Tips for proper use of insect repellents

Non-DEET repellents

There are effective insect repellents registered in Canada that contain active ingredients other than DEET. Instructions for proper use are listed on each product label.

Non-DEET products include repellents with p-menthane-3, 8-diol (PMD), also known as lemon-eucalyptus oil. This product has been shown to be as effective as DEET, but it only protects against mosquitoes for about 2 to 3 hours. Lemon-eucalyptus oil should not be used on children younger than 3 years old. It should not be applied more than twice a day.

Soybean oil products are also effective mosquito repellants, but these are not widely available in Canada. Products with the substance picaridin are also effective, but these are not available in Canada.

For a complete list of registered products, visit the Health Canada Pest Management Regulatory Agency at www.hc-sc.gc.ca/cps-spc/pest/part/protect-proteger/use-utiliser/_mosquito-moustique/index-eng.php.


BC Centre for Disease Control


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