QUESTION from Kate in New Orleans, Louisiana: What bug spray ingredients are safe, and which should be avoided, especially for kids?
MOM DETECTIVE ANSWER: Thank you for the question, Kate! At this time of year, I think all of us are thinking about keeping bugs at bay. And the top three buggiest states in the country are Florida, Louisiana, and Texas. So bugs are a major issue where you live.
For many parents, this isn’t a simple question. Depending on where you live—from ticks to mosquitoes—there can be very real consequences to bug bites. At the same time, using pesticides or insecticides on and around kids can be a detriment to their health.
While each family’s situation is different, I will break down some of the common ingredients in bug sprays. So you can decide for yourself and your family.
In any insect repellant, there are “active” ingredients and “inactive”—or “inert”—ingredients. All the active ingredients have to be approved by EPA as registered pesticides permitted for use in this capacity. However, take that with a grain of salt, as one should always use an abundance of caution around active ingredients that are designated as killing agents. High-risk pesticides, even though approved for use by a government agency, are increasingly cited in epidemiological studies as significant risk factors in diseases such as Alzheimer’s, Parkinson’s, multiple sclerosis, and more.
On the other side of the spectrum, there are many things registered as pesticides that might surprise you, ranging from surfactants in your average dishwashing soap to food-grade oils such as sesame and garlic oil.
That said, not all pesticides behave the same in relation to human health or the environment. In fact, EPA has a list of exempted minimum risk pesticides, which is where you can find these naturally derived active ingredients. Those are the more common, less chemical bug repellent ingredients. Be aware that concentrations must be stated on the package, but you don’t necessarily know how effective that concentration will be when using the product.
Among the most common naturally derived ingredients are:
Citronella Oil—Often used in candles and other repellents, it’s only found to be 50% effective at reducing bug bites. It has been named by the EU as an allergen and by Health Canada as a suspected carcinogen.
Lemongrass Oil—This plain and simple essential oil has been proven effective at repelling insects such as mosquitoes and house flies.
Mint and Spearmint Oil—Gardeners from around the world swear by various mint plants and oils to ward off bugs, from mosquitoes to spiders and other garden disruptors. The supporting science on the topic is less robust and could use more inspection, as there may be some promise.
It should be noted that plant ingredients can be very potent, and they are the basis for many pharmacological medicines. Often, plants contain compounds that make them pest and predator resistant in the wild, and this makes their extracts naturally useful in pest control. However, they are irritating for some people and should be used judiciously. Test a small patch of skin before applying broadly. More information on alternatives can be found here.
Some of the most common synthetic, higher risk, yet efficacious insecticide ingredients are:
- DEET (or N,N-Diethyl-metatoluamide, as it’s also known) is part of the toluene class of chemicals. It’s considered the most effective bug repellent, and it also repels ticks. It is not advised for use on infants, and its usage is limited for children under the age of two in Canada. However, the tradeoff may be worth it when taking into account the reasons for use and the effectiveness of alternatives. However, DEET is also linked to possible neurotoxicity that may lead to physiological and behavioral problems. Warnings for children can be scary. The method of action for DEET is not fully known, but it is thought to disrupt the insect’s ability to navigate the skin of humans. It should not be used in a prolonged manner but is deemed safe for certain use cases described here.
- Permethrin is one of more than 100 pesticides in the pyrethroid class of pesticides, and it is one of the most frequently used to treat bug-resistant clothing, mosquito netting, and outdoor gear. And it is used in bug sprays too. Worldwide, permethrin is also used as a pesticide on crops. EPA recognizes it as a probable carcinogen through oral delivery. It is toxic to honeybees, fish, and aquatic life.
- Cyflutherin, another pyrethroid pesticide, structurally resembles DDT. Similarly, it accumulates in fatty tissues, the central nervous system, and in the environment. It is toxic to bees and aquatic life.
The general category of pyrethroids are lipophilic, so they can easily cross the blood-brain barrier and become toxic to the central nervous system. The WHO lists synthetic pyrethroids as neuro-poisons, and they can alter nerve function. Highly acute reactions to pyrethroids include dermatitis and asthma-like reactions, nausea, lack of coordination, and burning, itching sensations. The most severe poisoning cases have been reported in infants, due to the fact that babies cannot efficiently break down pyrethroids.
As with most insecticides, more is not better. If you decide to use a conventional pest product, know that one application is considered saturation. Be sure to read the application guide for full understanding of coverage and instructions on use.
While all of these insecticides are recommended by the American Academy of Pediatrics, many parents prefer something less potent and risky to keep bugs away at the average backyard BBQ.
Another note of caution: insect repellent is often used on vacation when sunscreen is also being applied. While that may seem like a good idea, I don’t recommend combining products. Sunscreens require repeat application for use, whereas most bug sprays should not be applied as frequently. The other issue is that certain ingredients used in sun care may have a penetration enhancing effect and you do not want to have pesticides penetrate the skin deeply.
Here are some ways to prevent and/or mitigate harmful effects from insect repellents:
- Dawn and dusk are the buggiest times. So dress in plain, lightweight, long-sleeved shirts and long pants to protect from bugs.
- Don’t allow standing water to gather in your yard. This avoids bug breeding zones and reduces the need for other pest control products such as foggers and mists.
- Apply bug repellant to clothing, rather than skin, whenever possible.
- Do not overapply. Follow instructions for exact use.
I hope this helps you determine which bug spray is right for you and your family this season.