Mosquito Repellents: What’s in Them, and Are They Safe for Your Kids?

What’s worse than a red, itchy mosquito bite? A red, itchy mosquito bite that infects your beloved with West Nile Virus or another mosquito-transmitted disease found in the U.S.. Protecting your kids against mosquitos is important when they’re playing outside, and this requires a two-pronged approach.

The first prong involves reducing your mosquito population, which you can read all about in my article entitled “Mosquito Control for the Back Yard.” The second prong involves applying a mosquito repellent to your child’s person when he goes outside to play.

The Centers for Disease Control stresses that applying mosquito repellent is the best way to avoid getting bitten by the little buggers. But what mosquito repellents work best? And which ones are the safest for the kiddos? This guide should sufficiently answer both of those questions and more.

The Active Ingredients in Mosquito Repellents

Mosquito repellents don’t kill mosquitos, but rather confuse the bejeebers out of the neurons and receptors on their antenna so that they can’t detect the chemical markers on the skin that indicate there’s blood to be feasted on beneath.

There are five EPA-registered active ingredients that are used in most of the mosquito repellents on the market today. Here’s a rundown of them.

DEET

DEET, chemical name N,N-diethyl-meta-toulamide, is the most common active ingredient in insect repellents. DEET is a chemical that was developed by the Army in the early 1950s and registered for public use in 1957. It protects against mosquitos, ticks, and other biting insects.

What products contain DEET?

DEET is the active ingredient in:

Cutter All Family Insect Repellent (7% DEET)
OFF! Family Care Smooth & Dry Insect Repellent (15% DEET)
Cutter Backwoods Insect Repellent (25% DEET)
Sawyer Ultra 30 Insect Repellent (30% DEET)

Is DEET safe for kids?

According to the Environmental Protection Agency, the World Health Organization, and the American Academy of Pediatrics (AAP) Committee on Environmental Health, it’s safe to use DEET on children older than two months. Here are the AAP’s updated recommendations for using DEET on children:

“Insect repellants containing DEET with a concentration of 10% appear to be as safe as products with a concentration of 30% when used according to the directions on the product labels.”

Health Canada has different recommendations for using products with DEET:

O to 6 months: Don’t use DEET.
6 to 24 months: Only use 5% to 10% DEET, and only when the bug risk is high. Don’t apply it more than once a day.
2 to 12 years: Use 5% to 10% solutions, limit applications to three a day, and avoid prolonged use.
General population: Don’t use products containing more than 30 percent DEET.

The Environmental Working Group (EWG) warns that in intense doses, DEET may induce neurological damage. It’s very important to keep repellents containing DEET out of the reach of children and to apply it only as frequently as is directed. The EWG cites studies showing that daily use of DEET can cause headaches and difficulty concentrating, among other symptoms. Always follow the directions and precautions when using products containing DEET.

Other things to know about DEET

There’s a widely circulated myth that DEET is the same thing as DDT. It’s not. DDT was banned in the U.S. in 1972. DEET has a strong chemical odor that can annoy scent-sensitive people and make it smell pretty toxic. It can also dissolve or damage plastic, vinyl, and rubber.

IR3535

IR3535, chemical name 3-[N-Butyl-N-acetyl]-aminopropionic acid, ethyl ester, is structurally similar to a naturally occuring amino acid known as B-alanine. Most repellent formulations contain 10 to 30 percent IR3535 and will repel mosquitos, ticks, and other biting insects. A Consumer Reports test found that 20 percent IR3535 solutions are slightly less effective than 10 to 30 percent DEET solutions for repelling mosquitos that carry dengue, yellow fever, and encephalitis, but it performs as well as DEET against deer ticks and species of mosquitos that carry West Nile virus.

What products contain IR3535?

IR3535 is the active ingredient in:

Coleman SkinSmart DEET-Free Insect Repellent (20% IR3535)
RR Lotion Insect Repellent (10% IR3535)
Avon Skin So Soft, which contains sunscreen in addition to the repellent and is therefore not recommended.

Is IR3535 safe for kids?

IR3535 carries few safety risks aside from being very irritating to the eyes, according to the EWG. In Europe, where it’s been in use for decades, authorities have received no reports of health problems associated with IR3535, and it’s unlikely to pose any long-term effects with normal use.

Other things to know about IR3535

Like DEET, IR3535 can damage plastics. It’s often found in products that combine sunscreen and the repellent, but since sunscreen needs to be applied more often than repellent, using these can over-expose the user to IR3535. Combination sunscreen/insect repellent aren't recommended.

Picaridin

Picaridin, also known as KBR 3023, is a synthetic compound that resembles the natural compound found in pepper plants. Picaridin has been used in Australia and Europe for decades, but it’s only been available in the U.S. since 2005. It repels mosquitos, biting flies, ticks, fleas, and chiggers. The EPA data indicates that a 20 percent concentration of picaridin is effective against mosquitos and ticks for 8 hours, while a 10 percent concentration protects your child for about 3.5 hours.

What products contain picaridin?

Picaridin is the active ingredient in:

Avon Skin So Soft Bug Guard Plus (10% picaridin)
Sawyer Picaridin Insect Repellent (20% picaridin)
Natrapel (20% picaridin)

Is picaridin safe for kids?

According to Oregon State University’s National Pesticide Information Center, picaridin is safe for children. It’s considered practically non-toxic when inhaled, but in rare cases, it can cause skin or eye irritation. Less than six percent of the picaridin applied to skin is absorbed into the body, and humans excrete almost all of what is absorbed through their urine within a day of exposure.

Other things to know about Picaridin

According to the Environmental Working Group, Picaridin doesn’t have the pungent odor DEET has, and it doesn’t have the same neurotoxicity concerns. It evaporates more slowly from the skin than DEET and IR3535, which means it may repel mosquitos for longer periods of time.

Oil of Lemon Eucalyptus (OLE) and PMD

Oil of lemon eucalyptus, or OLE, is a biochemical pesticide that originates from an extract of the eucalyptus tree. The OLE is refined to extract the naturally occurring substance PMD (long chemical name para-menthane-3,8-diol.) Most OLE/PMD repellents have concentrations of 30 percent OLE and 20 percent PMD. According to the EWG, PMD concentrations of 20 to 26 percent OLE may perform as well against mosquitos and ticks as 15 to 20 percent DEET, although the EPA reports that PMD’s protection time is shorter than DEET’s.

What products contain OLE/PMD?

OLE/PMD is the active ingredient in:

Repel Plant-Based Lemon Eucalyptus Insect Repellent2 (30% OLE/65% PMD)
Cutter Lemon Eucalyptus Insect Repellent (30% OLE/65% PMD)
Coleman Botanicals Insect Repellent (30.9% OLE/65% PMD)

Is OLE/PMD safe for kids?

The CDC warns against using products containing PMD on children age three and under. According to the EWG, that’s because the dangers of these products to children have not been well-tested, since the EPA doesn’t require as much safety testing for biochemical pesticides as they do for synthetic versions. Citronello and other chemicals in the OLE extract are known allergens, but synthetic PMD, which can be found in some repellents at a concentration of 10 percent, has less of a risk of allergic reactions.

Other things to know about OLE/PMD

It’s important to note that plain old oil of lemon eucalyptus essential oil isn’t recommended by the EPA or other expert organizations as an insect repellant, as it hasn’t undergone validated testing for safety and efficacy.

2-Undecanone

2-undecanone is a synthetic version of a compound found in wild tomatoes, bananas, and other plants. Because of its strong odor, it’s used in the perfume industry and has some success an insect repellent. 2-undecanone is the least toxic of the active ingredients in repellents—it’s also classified by the FDA as a flavoring agent for food—and it can be applied as often as needed.

What products contain 2-undecanone?

2-undecanone is the active ingredient in Bite Blocker BioUD, the only EPA-registered product that contains it. Bite Block BioUD protects against mosquitos for up to five hours, according to EPA and USDA field and lab studies. Bite Blocker Organic Insect Repellent Spray is an organic repellent, and it's waterproof.

Is 2-undecanone safe for kids?

Bite Block BioUD and Organic Insect Repellant Spray are safe for children.

Other things to know about 2-undecanone

Bite Block is non-flammable, unlike most other repellents, and it doesn’t damage plastic.

Botanical Insect Repellents

I tried to use as few toxic chemicals as possible when Ruby was a teeny little thing, and during that period, I concocted my own “mosquito repellents” from essential oils. After all, many essential oils are natural insecticides and repel a number of bugs. Some of my recipes worked okay. Others only smelled really freaking good but did nothing to ward away the critters.

In general, the EWG recommends against using botanical repellents, since they vary in effectiveness and only repel bugs for a short time—if they effectively repel them at all. The EPA and the EWG recommend that people in high-risk areas avoid botanically-based insect repellents other than oil of eucalyptus and PMD. Products made with botanicals often contain known allergens that can do a number on young or sensitive skin.

Still, if you’re as hellbent on using botanicals as I once was, the EWG says that it might be worth your while to try some out to see how they work for you. Just because they haven't been proven to work effectively doesn't necessarily mean they don't work effectively. But be sure to try botanicals out on a small patch of skin before slathering it all over your child's body, since allergic reactions are fairly common.

The essential oils the EWG recommends trying are:

Castor oil.
Cedar oil.
Citronella oil.
Clove oil.
Oil of lemon eucalyptus (PMD 65%).
Geraniol oil.
Lemongrass oil.
Peppermint oil.
Rosemary oil.
Soybean oil.

Read up on making essential oil concoctions to learn what to use as a carrier for the oils (I usually used witch hazel or grape seed oil), how much essential oil to use, and how to store your solution. I never really followed a recipe or wrote down the recipes I made up. I just tried out combinations I thought would smell nice. Looking back, I wish I'd been more scientific about it. No matter what you put in your repellent, note that any essential oil repellent will require very frequent applications. But they smell heavenly, so you probably won't mind.

What I Use

These days, I mostly use Avon Skin So Soft Bug Guard Plus, which contains 10% picaridin. It smells nice, it doesn't dry Ruby's skin out, and it works really well. Sometimes I buy Repel Plant-Based Lemon Eucalyptus Insect Repellent2 (30% OLE/65% PMD), which has an earthy, citrusy smell that I really like.

I save the DEET for times when the mosquitos are particularly heavy and bothersome and require the big guns. Even though I know that DEET is far, far safer for my child than an infected mosquito, I prefer to use products containing it as infrequently as possible. When I do spring for the DEET, I always have good luck with Sawyer Ultra 30 Insect Repellent (30% DEET), which is mostly odorless and lasts a long time, unlike some brands that stink to high hell and seem to last about five minutes.

Tips for Safely Using Mosquito Repellents

The American Academy of Pediatrics offers the following guidelines for using insect repellents on your children.

Don’t use products that contain both sunscreen and repellent, since sunscreen needs to be applied more often than repellent.
Don’t apply repellents to skin that’s covered by clothing. Never spray it under clothing.
Keep the repellent away from cuts, wounds, rashes, and irritated skin.
Don’t spray the repellent on the face, but rather spray it into your hands and then rub it on your child’s face.
Use just enough to cover the clothes and exposed skin. Heavy applications don’t work better or longer and can increase risks.
Don’t let the young ones apply the repellent themselves.
Use the spray outside, in a well-ventilated area.
Don’t spray repellents near food.
Reapply the repellent if your child sweats it off or gets in the pool.
Reapply the repellent as infrequently as possible, no more often than is recommended on the label.
Have your child wash her hands before eating.
Wash the treated skin or toss your child in the tub once he's inside for the night.
If your child gets a rash or another reaction from the repellent, wash it off with soap and water and call your child’s pediatrician or the Poison Control Center. Have the bottle handy when you call.
Wash your child's clothes before she wears them again.
Insect repellent wrist bands, according to the AAP, are ineffective and shouldn’t be used.

What to Do if Your Kid Gets Bit by a Mosquito

Unless you enclose your child in a mosquito-proof plastic bubble for the duration of his childhood, he’s probably going to get mosquito bites now and then. Wash the bite, and dab it with alcohol or slather it with calamine lotion to reduce the itching. Try to keep Junior from scratching (good luck!), and keep the bite clean to prevent infection. If the itching is really bad, or there are a lot of bites, a dose of child's Benadryl can offer some relief.

Do you have a favorite mosquito repellent or mosquito bite remedy that seems to work for you? We’d love to hear about it in the comments!