A Guide to Understanding Bug Repellents
To follow the news is to know that there are chemicals in our waterways and carcinogens in our food supply. But what and where and how much? That’s where things get murky. Which is why we tapped Nneka Leiba, the director of healthy living science at the Environmental Working Group. In her monthly column, Leiba answers our most pressing concerns about toxicity, the environment, and the health of the planet. Got a question for her? You can send it to firstname.lastname@example.org.
Insects and other bugs can carry dangerous, even deadly, diseases. A report from the Centers for Disease Control and Prevention found that the number of reported cases of disease from mosquito, tick, and flea bites more than tripled between 2004 and 2016.
Since 2004, nine new germs spread by mosquitoes and ticks have been discovered or introduced in the US, including the mosquito-borne viruses Zika and chikungunya. And while the CDC has reported no cases of Zika transmission in the US in 2018, it warns that pest-borne diseases are “a large and growing public health problem in the United States.” Experts predict the number of bites and infections will continue to rise because as our climate warms, the habitats and breeding grounds of ticks and mosquitoes expand.
People have raised concerned about the potential toxic effects of some common active ingredients in bug repellents, but it is important to note that the benefits of bug repellents far outweigh any potential safety concerns.
Here are some things to consider when choosing a bug repellent: What part of the country do you live in? Where do you plan to travel? What are the predominant bugs of concern in those locations? Are you pregnant? Will you use the product on children? Recently, the Environmental Working Group updated its Guide to Bug Repellents to help people choose the right product for each situation. Based on testing data, the EWG’s top choices for repellents include those that contain the active ingredients picaridin, DEET (at a concentration of less than 30 percent), and IR3535 (at a concentration of 20 percent) for protection from a variety of biting insects and ticks. And all three have good safety profiles and are registered with the Environmental Protection Agency, which means there is data on both their efficacy and their toxicity.
Beware of products with claims of 100 percent protection on their labels. There is no perfect, completely safe way to prevent bug bites, and no repellent is guaranteed to fend off all pests. Higher concentrations of chemical repellents are generally not more effective but may provide longer-lasting protection. Remember to reapply the product if you’ve been swimming or sweating.
For those of you concerned about the possible drawbacks of the common active ingredient DEET, picaridin is similarly effective and may be worth considering. EWG researchers have found that with proper application and precaution, both DEET and picaridin will effectively reduce your risk of contracting a life-altering disease with very low toxicity concerns. That said, these chemical repellents shouldn’t be used on infants under six months old, and some should not be used on young children. (Consider the EWG’s Guide to Bug Repellents: For Kids for further information.) Clothing should be the first choice for mosquito protection.
Botanical-based repellents may be worth considering if bug-borne diseases are not a concern where you are going.
If you need both sun and mosquito protection, the CDC recommends buying two separate products. It advises you to put on sunscreen first and then apply mosquito repellent. Studies show that ingredients in sunscreen could increase your skin’s capacity to absorb repellent.
Here are some additional tips for increasing protection against insect bites:
Wear pants, socks, shoes, and long-sleeved shirts, especially when venturing into heavy brush with likely bug infestations. Tuck pants into socks to protect the ankles.
Take extra precautions to avoid bug bites if you are in a high-risk area for Lyme disease, West Nile virus, or other mosquito- or tick-borne illnesses.
Use nets and/or fans over outdoor eating areas, and place nets over strollers and baby carriers.
Read repellent labels to learn about safe usage and protection from bug species known to infest your area.
Use products with the lowest effective concentration of repellent chemicals, particularly on children.
When using repellent on children, apply it on your own hands first and then apply on the child.
Use products in lotion, pump, or towelette form instead of aerosol sprays in pressurized containers to avoid inhaling chemicals.
Check for ticks thoroughly after returning indoors and remove ticks properly.
Wash clothing and repellent-coated skin when your kids come indoors or at the end of the day.
Consider permethrin-treated clothing if you are looking for a higher level of protection from ticks. Use these products with caution, read labels, and wash treated clothing separately from other clothes.
Avoid bug zappers, repellent wristbands and candles, and clip-on repellents. They are less effective than skin or clothing treatments.
Get rid of buckets, planters, or any other place that has standing water—that’s where mosquitoes breed.
As the director of healthy living science at the Environmental Working Group, Nneka Leiba, M.Phil., M.P.H., translates complicated scientific topics, particularly ones dealing with the effects of everyday chemical exposures on our health, into easily accessible tips and advice. Leiba has become an expert in a wide range of issues, including the safety of ingredients in cosmetics and other consumer products, and drinking water quality. She earned graduate degrees in zoology and public health from the University of the West Indies and Johns Hopkins University, respectively.