If you must be outside when mosquitoes are active, applying a mosquito repellant – either a spray or wipe – to your skin or clothing will help protect you from mosquito bites. Just make sure to use products containing one of the four active ingredients that have been registered and approved as safe and effective by the U.S. Environmental Protection Agency (EPA).
Skin Products — Look for These Active Ingredients
The EPA says mosquito repellents that contain one of the following active ingredients typically provide reasonably long-lasting protection:
- DEET (Chemical Name: N,N-diethyl-m-toluamide or N,N-diethly-3-methyl-benzamide)
- DEET-based repellent may be used along with a separate sunscreen product, if both are applied according to label instructions.
- DO NOT use a product that combines DEET-based repellent and sunscreen in one bottle because the instructions for use of insect repellents and use of sunscreen are different. In most situations, insect repellent does not need to be reapplied as frequently as sunscreen.
- DEET should not be used on infants less than 2 months old. The efficacy of DEET plateaus at a concentration of 30%, the maximum concentration currently recommended for infants older than 2 months, children, and adults.
- Picaridin (also known as KBR 3023 or Bayrepel) (Chemical Name: 2-(2-hydroxyethyl)-1-piperidinecarboxylic acid 1-methylpropyl ester)
- Oil of Lemon Eucalyptus (also known as PMD) (Chemical Name: para-Menthane-3,8-diol);
- This is a synthesized version of oil of lemon eucalyptus, not the pure (essential) oil of lemon eucalyptus. The pure oil is not registered with the EPA as an insect repellent.
- Products containing oil of lemon eucalyptus should not be used on children under 3 years of age.
- IR3535 (Chemical Name: 3-[N-Butyl-N-acetyl]-aminopropionic acid, ethyl ester)
For more information, see Active Ingredients in Insect Repellents (EPA).
Traveling oversees? See CDC Travelers' Health website for additional recommendations concerning protection from insects when traveling outside of the United States.
Protection Times Vary
Typically, the more active ingredient a product contains, the longer it provides protection from mosquito bites.
But just because one product has a 10% concentration of an active ingredient doesn't mean it will work exactly the same as another product containing a 10 % concentration of a different active ingredient.
How well a repellent works and how long it lasts will vary, depending on several factors:
- The type of active ingredient
- The amount of active ingredient
- Sustained release products may offer longer protection.
- Products that are not sustained release and that have less than 10 percent active ingredient may protect you for only 1-2 hours.
- Products that have 10-50 percent active ingredient will protect you longer. For most products, concentrations higher than 50 percent don't improve protection times. For products containing DEET, concentrations higher than 30 percent don't improve protection times.
- The types of mosquitoes nearby
- The temperature
- Each 50°F increase in temperature can lead to as much as a 50% reduction in protection time.
- Wash-off from sweat, rain, or water.
Choose a repellent that provides protection for the amount of time that you will be outdoors. A product with a higher percentage of active ingredient is a good choice if you will be outdoors for several hours, while a product with a lower concentration can be used if time outdoors will be limited. Simply re-apply repellent if you are outdoors for a longer time than expected and start to be bitten by mosquitoes.
Make sure to follow product directions when reapplying repellent.
Facts About DEET (N, N-diethyl-m-toluamide)
- The protection time from mosquito bites for products containing DEET depends on the concentration of DEET*:
- 23.8% DEET = 5 hours of protection
- 20% DEET = 4 hours of protection
- 6.65% DEET = almost 2 hours of protection
- 4.75% DEET = roughly 1½ hours of protection
- Do not apply DEET to children under 2 months of age.†
- The maximum concentration of DEET currently recommended for infants older than 2 months, children, and adults is 30%.† Products containing 30 percent DEET provide long lasting protection. Concentrations higher than 30% do not provide significantly increased or longer repellent effect. Higher concentrations increase the degree to which DEET can become poisonous, which occurs when DEET is applied excessively, too frequently, or misused in a way that is not consistent with the label directions.
- Though millions of people have used repellents without a negative reaction, people with known or suspected metabolic disorders should check with their physicians before using a repellent containing DEET.
- DEET is the most effective insect repellent currently available. It has been used safely for more than 40 years by millions of people worldwide.
- You can spray clothing with repellents containing Permethrin or DEET to help keep mosquitoes from biting through thin clothing.
*Fradin, M. S. and J. F. Day (2002). "Comparative efficacy of insect repellents against mosquito bites." New England Journal of Medicine 347(1): 13-18.
†American Academy of Pediatrics (2003). Follow safety precautions when using DEET on children. AAP News. June.
Follow These Precautions When Using Insect Repellents
- Always follow the instructions on the product label.
- Apply repellents only to exposed skin and/or clothing (as directed on the product label.) Do not use repellents under clothing.
- Never use repellents over cuts, wounds or irritated skin.
- Do not apply to eyes or mouth, and apply sparingly around ears. When using sprays, do not spray directly on face – spray on hands first and then apply to face.
- Do not allow children to handle the product. When using on children, apply to your own hands first and then put it on the child. You may not want to apply the product to children's hands.
- Use just enough repellent to cover exposed skin and/or clothing. Heavy application and saturation are generally unnecessary for effectiveness. If biting insects do not respond to a thin film of repellent, then apply a bit more.
- After returning indoors, wash treated skin with soap and water or bathe. This is particularly important when repellents are used repeatedly in a day or on consecutive days.
- Wash treated clothing before wearing it again. (This precaution may vary with different repellents – check the product label.)
- If you or your child get a rash or other bad reaction from an insect repellent, stop using the repellent, wash the repellent off with mild soap and water, and call a local poison control center for further guidance. If you go to a doctor because of the repellent, take the repellent with you to show the doctor.
- Avoid spraying repellents in enclosed areas or around food.
Treat Clothing and Camping Gear with Permethrin
Products that contain permethrin are recommended for use on clothing, shoes, bed nets and camping gear, and are registered with EPA for this use. Do not apply permethrin directly to your skin.
Permethrin repels and kills mosquitoes and ticks. You can:
- Spray permethrin insecticide on clothing and shoes
- Soak clothing in permethrin soak kits
- Buy pemethrin-treated clothing that will continue to repel and kill mosquitoes and ticks even after repeated washing.
The EPA does not recommend any additional precautions for using registered repellents on pregnant women, nursing moms, or children.
See the CDC Travelers' Health website for additional recommendations concerning protection from mosquito-borne (and other) diseases when traveling outside of the United States.
For More Information
These online resources contain additional information about repellents and recommendations for their use on adults and children.
Also see Clemson University's online library of Pesticide Safety information.