Insect Repellents

Printer-friendly PDF version

Why should I use insect repellent?

Insect repellents help people avoid mosquito and/or tick bites. Avoiding mosquito and tick bites can prevent Eastern equine encephalitis, West Nile virus, Lyme disease and other illnesses that can be transmitted by mosquitoes and ticks.

When should I use insect repellent?

Apply mosquito repellent when you are going to be outdoors between dawn and dusk or at other times when mosquitoes are active. Apply tick repellent when you will be in wooded, brushy, or grassy places where ticks may live.

Return to Top

Which repellents should I use?

Repellent FlyerUse repellents that are registered by the Environmental Protection Agency (EPA) because those products have been evaluated for safety and effectiveness. Look for the EPA-registration number on the label. Read the label carefully to make sure the product is effective against the type of insect you wish to repel. The label may also contain important information about how to use the product safely.

Flyer: How do I choose an insect repellent? PDF document

Most of the EPA-registered mosquito or tick repellent products contain one of the following ingredients:

DEET (N,N-diethyl-meta-toluamide)- is an ingredient used to repel mosquitoes and ticks. DEET has been tested against a variety of biting insects and has been shown to be very effective. Keep in mind that a higher percentage of DEET in a repellent does not mean that your protection is better—just that it will last longer.

Picaridin (KBR 3023) is a colorless, nearly odorless liquid active ingredient that is used as an insect repellent against biting flies, mosquitoes, chiggers, and ticks. Picaridin products were sold in Europe and Australia for several years before being introduced to the U.S. market in 2005.

Oil of lemon eucalyptus is found naturally in eucalyptus leaves and twigs. It was first registered in 1948 as an insecticide and miticide (kills insects and mites) and today is found in both lotion and spray insect repellents. p-Mentane-3,8-diol is the chemically synthesized version of oil of lemon eucalyptus. The label on these products specifies that they should not be used on children under the age of three years.

IR3535 (3-[N-Butyl-N-acetyl]-aminopropionic acid, ethyl ester) is used as an insect repellent against mosquitoes, deer ticks, and biting flies. This biopesticide was registered with the EPA as an active ingredient in 1999. IR3535 has been used as an insect repellent in Europe for 20 years with no significant harmful effects.

Repellents for use on clothing

Permethrinis an insecticide and insect repellent that can be used on clothing, shoes, bed nets, and camping gear. Permethrin should never be applied to skin. Permethrin-treated clothing repels and kills ticks, mosquitoes, and other insects and retains this effect after laundering. This may be a good choice for people who spend significant time outside.

Products containing DEET can also be applied to clothing.

Return to Top

How long do repellents work?

Length of protection varies with the amount of active ingredient, air temperature, amount of physical activity and perspiration, water exposure and other factors. Re-apply repellents according to label instructions.

Are insect repellents safe?

Yes, products containing DEET, Picaridin, oil of lemon eucalyptus, IR3535, and permethrin are safe when used according to the directions on the label. Each of these ingredients has been registered with the EPA. EPA registration of repellent active ingredients indicates the materials have been reviewed and approved for efficacy and human safety when applied according to the instructions on the label.

How should insect repellents be applied safely?

Carefully follow the directions on the label.

Return to Top

Are other repellents effective?

There are other repellent products that can be applied directly to skin which provide some protection from mosquito bites. However, studies suggest that other products do not offer the same level or duration of protection as products containing DEET, Picaridin, oil of lemon eucalyptus, or IR3535.

People should choose a repellent that they will use consistently and that will provide sufficient protection for the amount of time that they will be spending outdoors. Product labels often indicate the length of time that protection can be expected from a product. Persons who are concerned about using insect repellents may wish to consult their health care provider for advice.

More information

Return to Top