How to Use Insect Repellents Safely

Medically Reviewed by Zilpah Sheikh, MD on January 15, 2024
9 min read

No one likes bug bites. Along with itching and irritation, bites from an infected mosquito, tick, or other insect can lead to illnesses like West Nile virus, Zika virus, and Lyme disease. Bug repellent (also called bug spray) helps keep the bugs away and lowers your chances of getting insect-borne illnesses.

Bug repellents can be sprays, lotions, creams, and sticks. Many bug repellents use a chemical called N,N-diethyl-m-toluamide, or DEET for short. As long as you follow the directions carefully, doctors say that the benefits of using DEET outweigh the risks. People have been using DEET to keep bugs away for over 60 years. 

Another chemical that's used in bug repellents is called picaridin (chemical name, or KBR 3023). Picaridin is more common in Europe than in the U.S., and it is a synthetic (human-made) copy of chemicals found in the black pepper plant. 

Some kinds of bug repellent use a natural product made from the lemon eucalyptus tree, called oil of lemon eucalyptus. A synthetic version of it is called para-menthane-diol, or PMD. The Environmental Protection Agency (EPA) says that DEET, picaridin, oil of lemon eucalyptus, and PMD are all safe to use on your skin if you use these products as directed. 

Sometimes, clothes and camping gear are treated with a chemical called permethrin. It's also in some sprays and powders, and it's used to kill fleas and ticks in dogs. It can be toxic for cats. Most bug repellents work by confusing bugs and keeping them away from you, but permethrin kills bugs directly. It can also be dangerous for your nervous system, especially if it is eaten. 

For this reason, using bug sprays with permethrin is not recommended, and it's important to keep it out of reach of children and pets. You should avoid petting animals that have been treated with flea products that use it. Permethrin-treated clothes and gear are effective at keeping bugs away, but they should be washed separately from your other laundry when you're done with them. Keep in mind that permethrin also kills "good" insects like bees, and might harm birds. Scientists aren't sure if permethrin is safe if you're pregnant.

With whichever kind of bug repellent you use, it's important to read and follow the directions on the label. These tips will help you use bug repellent safely: 

  • Do not apply bug sprays over cuts, wounds, or irritated skin.
  • Avoid putting on too much bug spray--use just enough bug repellent to cover your clothes and any exposed skin.
  • Do not put bug repellent on the skin under your clothes.
  • After returning indoors, wash treated skin with soap and water.
  • Wash treated clothing before wearing it again.
  • Avoid "two in one" sunscreen and bug repellent products--the concentration of DEET in a bottle tells you about how long it will last, and you should only use as much as you need to stay protected for the amount of time that you will be outside. But you should reapply sunscreen every few hours. When you use combination bug repellent and sunscreen products, you run the risk of using too much bug repellent.

Using bug repellent may cause skin reactions in rare cases. If you are using an aerosol or pump bug spray, use these precautions to avoid breathing it in: 

  • Do not spray in small, enclosed areas.
  • To apply bug spray to your face, spray it on your hands first and then rub it onto your face. Do not spray it directly on your face.

Children and babies might be more sensitive to bug repellents and other pesticides than adults. They're also more likely to lick skin that's been treated with bug spray, or accidentally swallow chemicals that are left within their reach. For that reason, it's important to store bug repellent in a safe place they can't get to, and keep a close eye on kids who are wearing it. 

Follow all the precautions described above. Here are some other tips for using bug repellent safely with babies and children:

  • In general, children should not handle bug repellent or put it on by themselves. Help older kids apply it, and make sure they only use a small amount.
  • To put bug spray on a child, put it on your hands and then rub it onto their skin. Do not spray children directly. 
  • Avoid children's eyes and mouth and use it sparingly around their ears.
  • Don't put bug repellent on children's hands. This is because kids tend to touch their eyes and mouth frequently.
  • Even when they are wearing bug repellent, it's important to check children’s hair and skin for ticks after they play outside, especially in areas with woods or tall grass. 
  • Put mosquito netting over their strollers and dress kids in lightweight, long clothing to keep bugs off their skin. Wearing long-sleeve shirts with collars and cuffed wrists and long pants tucked into their shoes or socks can help prevent bug bites. 

When selecting a bug repellent to use on your child, consider the following options:

DEET

DEET is considered to be one of the most effective bug repellents. The EPA says that it's safe for people of all ages. But the American Academy of Pediatrics (AAP) says not to use bug repellent on babies younger than 2 months old. Use caution putting it on premature babies, because their skin can be more sensitive. DEET is considered safe to use if you're pregnant.

The AAP recommends using repellents with no more than a 30% concentration of DEET for kids over 2 months. A 10% concentration of DEET protects for about two hours. Use the lowest concentration of DEET possible for the amount of time that kids will be exposed to bugs. You can find this information on the product label. In general, you will not need more than a 20-30% concentration of DEET. Bug repellents with high concentrations of DEET (over 50%) don't protect you longer or better.  

If possible, put repellents with DEET on your clothing instead of your skin. Look for a lotion or pump spray instead of an aerosol, so you don't breathe in as much of the chemical. Always wash your hands after touching DEET-based bug repellents--especially before handling food. To avoid skin reactions to DEET, make sure to wash it off with soap and water after you go back inside.

Drinking alcohol might increase the amount of DEET that your body absorbs. 

Keep pets away from bug repellents with DEET. 

Oil of lemon eucalyptus

Oil of lemon eucalyptus (chemical name p-Menthane-3,8-diol) is made from the leaves and twigs of the lemon eucalyptus tree. There is also a synthetic (human-made) version of it called para-menthane-diol, or PMD. Though they sound similar, oil of lemon eucalyptus is different from lemon eucalyptus essential oil, which shouldn't be used as bug repellent. Oil of lemon eucalyptus and PMD are almost as effective as DEET in keeping mosquitos away, though they don't work for as long as DEET does.  

The EPA says that oil of lemon eucalyptus and PMD are safe for people and the environment. The product can cause eye irritation, though, so avoid getting it in your eyes or spraying it on your face. Don't use bug repellents made with oil of lemon eucalyptus or PMD on kids under 3. Oil of lemon eucalyptus and PMD are safe if you're pregnant.

Natural products

There are many natural bug repellents available, for people who prefer to avoid DEET and other synthetic chemicals. They vary in how good they are at preventing bugs from biting you. 

  • Soy-based products. Soybean oil is the active ingredient in some "natural" bug repellents. While some studies found that it kept bugs away for a little while, other studies showed that it doesn't really prevent bites. 

  • Catnip is a plant in the mint family. Some studies have shown that bug repellent products made from catnip can protect you against mosquitos for up to 8 hours. But other studies found that it doesn't work as well as DEET in keeping the bugs away. It might be a good alternative if you prefer not to use DEET.

  • Avon’s Skin So Soft Bath Oil has been rumored to also keep bugs away. In a recent study, people who put on Skin So Soft only got half as many bites as people who did nothing, but it was found to only be 85% as effective as DEET. Plus, it only worked for a short amount of time.

  • Essential oils and other plant-based products. Many newer bug repellents use plant ingredients to try to keep the bugs away. Some include essential oils, which are a very concentrated version of certain chemicals from the plant. Scientists haven't studied essential oils that much, but some experts think they could be a good tool for keeping bugs away. 

    Some plants and essential oils that might work include: Chinese lovage, Indian rosewood, pine, lavender, catnip, geranium, jasmine, lemongrass, camphor, cedarwood, chamomile, cinnamon, juniper, cajeput, rosemary, niaouli, olive, loop-root mangrove, marigold, violet, sandalwood, may chang/Litsea cubeba, and turmeric.

    Never put essential oils in your mouth. Be careful using them around pets--some can be toxic to animals.    

Bug repellent is just one tool you can use to keep the bugs away. Here are some other approaches you can try: 

  • Fans. Mosquitoes have trouble getting around in the wind, and studies show that a fan can cut the number of bugs around you in half. Using a window fan, box fan, or overhead fan when you're sitting outside on a porch or stoop will confuse mosquitos and help keep them away. Experts say that fans also spread out the carbon dioxide we breathe out, which mosquitos use to find people to bite.  

  • Citronella candles. Despite the rumors, citronella candles--or other natural bug repellent candles--don't seem to work very well. Plus, when you inhale the smoke from the candle, you also breathe in any chemicals that are in it.

  • Wearable devices. These include bracelets, stick on skin patches, and clip-ons. Scientists have found that most of them don't work very well. They also only protect the area immediately next to the device, so the rest of your body still gets bitten.

  • Bug zappers. These devices use electricity to kill mosquitos. But they also kill a lot of the "good" bugs that eat mosquitos. In fact, one study showed that less than 1% of all bugs killed by bug zappers were mosquitos. They also kill bugs that birds and other animals need to eat, so they aren't very good for the environment.

  • Ultrasonic devices. These products claim to use sound waves to keep bugs away, but science hasn't shown that they work. Some ultrasonic devices might even make mosquitos bite more often, although scientists don't really know why.

  • Traps. These devices use various methods to attract and then trap mosquitoes. Many give off carbon dioxide, mimicking people's breath to lure the mosquitos into the trap. Others use pheromones, light, colors, heat, moisture, and other smells to draw mosquitos in. Some traps only work on certain species of mosquitos--for example, light traps don't work well for the kind of mosquitos that carry dengue fever and Zika virus. Scientists are still figuring out how well traps work. If you decide to use them, it's important to check on them often. 

  • Screens, nets, and other physical barriers. If possible, put up screens around your porch or other outdoor areas. Check your screens often, and use a patch kit to fix any holes. You can also put mosquito nets over strollers and seats. 

  • Make outdoor areas less welcoming to mosquitos. Mosquitos lay their eggs in water, and they like to hide under tall grass, sticks, and leaves to stay cool in the heat. Get rid of standing water by emptying out tools, toys, and containers that might hold water after it rains. If you have outdoor space like a yard, cut the grass and rake up leaves so that mosquitos have fewer comfortable spots. 

  • Bug repelling plants. Some plants naturally help keep bugs away, although research isn't complete about how well it works. If you are able to garden or have house plants in containers outside, you can try growing lavender, basil, thyme, mint, lemongrass, chrysanthemum, and marigolds. The mosquito plant is another obvious choice!