The effectiveness of insect repellents have been evaluated by numerous organizations including the Centres for Disease Control & Prevention (CDC) the Environmental Working Group (EWG), and the World Health Organization (WHO). Their research indicates that insect repellents containing: Picaridin, DEET, IR3535, and Oil of lemon eucalyptus are the most effective for repelling mosquitoes and ticks.

Picaridin, also called Icaridin, is recommended by the WHO. It is less irritating to the skin and eyes than DEET, does not dissolve plastic, has less odour, and evaporates more slowly than other compounds.

Use products containing 20% Picaridin for extended periods of protection..

IR3535 is a synthetic insect repellent used in Europe for 20 years. It is similar to DEET in some ways given the fact that it is irritating to the eyes and may dissolve some plastics. It is not quite as effective as DEET but is considered slightly less toxic.

Use products containing 20% IR3535 for extended periods of protection.

DEET is the most common insect repellent in North America. It has a strong odour and will dissolve many plastics and rubbers. It can be irritating to the skin and eyes and is more toxic than other products if used incorrectly. When used properly as directed it is an inexpensive and effective insect repellent.

Use products containing 20 - 30% DEET for extended periods of protection.

Follow directions, weaker formulas are suggested for children.

Oil of lemon eucalyptus (OLE) or PMD is an extract of the Australian eucalyptus tree. If used correctly it can be as effective as DEET but must be applied more frequently.

Use products containing 30% - 40% OLE for extended periods of protection.

Follow directions, it not recommended for use on children less than 3 years of age.

All Natural ingredients - All natural products tend not be reviewed as thoroughly as their synthetic counterparts. However Consumers reports evaluated several products containing natural ingredients recently . Product effectiveness varies dramatically depending on the type and concentration of ingredients used in their manufacture. It should be noted however that highly aromatic compounds are not suitable for use around people with allergies or chemical sensitivities. Even “all natural products “ can contain ingredients such as Pyrethrin from chrysanthemum flowers and lemon eucalyptus oil that can be toxic if used incorrectly. Check consumer ratings for effectiveness before purchase and check with your trip leader prior to use to ensure that these products are suitable for your upcoming trip.

Buying products locally:  Products with DEET are common everywhere. High ranking products containing Picaridin and OLE are available at outdoor suppliers such as MEC, Trailhead, Sail Bushtuka. Effective products containing all natural ingredients may only be available in health food stores or online.

How to use insect repellents – Some manufactures recommend that the consumer do not use these products beneath clothing, on open cuts or around the eyes and ears. If you use these products follow the manufacturer’s instructions for use and frequency of reapplication.

Useful Links: For additional information including selection guides that compare the effectiveness of common name brand products refer to the links below;

Finding the Right Insect Repellent – (EPA) Product Selection Guide

Using Insect Repellents Safely (EPA)

Insect Repellent Use and Safety (CDC)

Choosing and Using Insect Repellents (National Pesticide Info Center)

Consumer News – The Four Best Insect Repellents

Consumer Reports – Product Ratings including those with natural ingredients

Health Canada – Insect Repellents