Repellents and Other Personal Protection Guidance

registration numberThe Environmental Protection Agency (EPA) registers active ingredients used in insect repellents. These are:  DEET, picaridin, IR3535, Oil of Lemon Eucalyptus (OLE or PMD), or 2-undecanone. EPA-registered products have an EPA-registration number on the label.

This assures that the active ingredient in the product you are using has been reviewed for safety and efficacy. Always follow product instructions.

For Children

In 2003, the American Academy of Pediatrics developed guidance for using DEET-based repellents, noting that these products can be used on children 2 months of age or older in concentrations (What’s Concentration?  Click here) up to 30%, following label instructions. Since then, picaridin and IR3535 have been added to this guidance, Use mosquito netting and clothing to help protect infants younger than two months old.

It is an EPA regulation that children must be 3 years old to use products containing Oil of Lemon Eucalyptus.  EPA has no age or concentration restrictions on any of the other registered active ingredients.

Why 30%?  The relationship of the amount of active ingredient in the product to the length of time it will help provide protection is a linear one up to about 50%. A 30% concentration product will provide about 8 hours of protection against mosquitoes. A 50% product lasts about 10 hours.  A 100% about 12 hours.  Experts suggest there’s really little need, under routine circumstances, to use more than a 30% concentration product, which can be reapplied as necessary.  Those exposed to swarms of mosquitoes (fishing in Alaska, etc.) may want to use a higher concentration product.


Generally, the higher the concentration of active ingredient in the product, the longer the protection time. So, more is not ‘better’, it’s ‘longer’.

For mosquitoes all concentrations will work well…but for different lengths of time.  5% concentration products work for about  1.5 -2 hours. 30% for up to 8 hours.

For ticks, the Centers for Disease Control and Prevention (CDC) recommends using an EPA-registered repellent with at least a 20% concentration. Protection times may be shorter for repelling ticks than for mosquitoes, so you may need to reapply repellent more often.

Applying Repellents

Apply sparingly to exposed skin.  Use a light spray on clothing to help repel ticks and to repel mosquitoes if your clothing is sheer and mosquitoes can bite through it.

Smooth repellent onto exposed skin to get even coverage, as you would a sunscreen or body lotion product.  For additional tips and application to children, click here.

Repellents should to be applied directly to exposed skin (and in some cases on clothing).  Spraying randomly around your body will NOT provide appropriate protection.  Parents can apply to children by putting the repellent on their own hands then smooth it evenly on the child’s exposed skin.

For use with sunscreen products, click here.

Expert Advice on DEET-based Repellents

Experts from the Centers for Disease Control and Prevention (CDC), leading medical and public health organizations, universities, and health advocacy organizations comment on the safety and efficacy of DEET-based repellents. Learn more.

The American Academy of Pediatrics and other medical organization also encourage the use of repellents.

For pregnant women and breast-feeding mothers who live in areas where mosquito- and tick-borne diseases are found, CDC, the American College of Obstetrics and Gynecology and the World Health Organization encourage the use of repellents to help prevent bites that might transmit diseases of concern.

Clothing Can Help Prevent Bites

Dress appropriately: wear light-colored clothing. This makes it easier to spot mosquitoes and ticks.

pants in socksFor ticks, wear long pants and shirts with long sleeves. Tuck in shirts into pants and tuck pants into socks. Wear closed-toe shoes.

For mosquitoes, cover as much of your body as you can with clothing.  Aedes mosquitoes like to bite knees-to-feet, so be aware and dress accordingly. Click here for more on mosquito biting behaviors.

Consider using permethrin on clothing and gear. It’s an insecticide that kills ticks and mosquitoes on contact. (Repellents do NOT kill mosquitoes and ticks.) Follow label instructions carefully. Do NOT use permethrin on skin.


where to check for ticks
Where to check for ticks

Find ticks as soon as possible.  The likelihood of disease transmission increases the longer the tick is attached.

  • What to look for
  • Check clothing for ticks. Then, tumble clothes in a dryer on high heat for 10 minutes to kill ticks on clothing as soon as you come indoors.
  • What to do with ticks you find. Put any ticks you remove from skin or clothing into a container with alcohol (Hand sanitizer works well) to kill them.
  • Examine gear and pets. Ticks can hitchhike on clothing and pets, then move to a person later, so carefully examine pets, clothing, and gear.
  • Shower after coming inside. Showering right away can help to wash off unattached ticks and offers a good opportunity to do a tick check.

Additional Resources