The Deets on DEET: What parents should know about Health Canada’s latest research on insect repellents for kids

For many of us, summer means making the most of our great Canadian landscape. Trips to the beach, picnics, backyard barbecues, hiking trails, and children’s summer camps are great ways to enjoy the best of our weather and our wonderful natural resources. However you enjoy the great outdoors, there’s a good chance you use bug spray to cope with those tiny unwanted guests who show up to spoil the fun. The only thing that ruins a barbecue faster than rain is a swarm of mosquitoes!

DEET is one of the most common active ingredients in bug sprays in Canada. It’s used to repel biting insects such as mosquitoes, blackflies, and ticks. This not only spares us the dreaded itch and sting of bites, but also helps to prevent the spread of illnesses like West Nile virus and Lyme disease. DEET is a registered active ingredient that has been approved by Health Canada for use by children and adults. The buzz on products like DEET can be confusing, but let’s take the sting out of speculation!

Recently, when DEET came up for its regular safety re-evaluation, Health Canada scientists decided they needed more data related to children’s exposure to bug spray. The average child’s use of bug spray might not be the same as that of an adult, and smaller bodies may respond to chemicals differently.

To make the best possible decisions, it’s important to know as much as possible about how a product might impact different people based on the amount they use.

Pesticides like DEET are regulated by Health Canada to make sure they pose minimal risk to human health and the environment. Under the authority of the Pest Control Products Act, Health Canada registers pesticides after a careful, science-based evaluation determines the risks are acceptable.

Pesticides are also regularly re-evaluated to help ensure they continue to meet current scientific standards. With rigorously collected, up-to-date information on the exposure and effects of the chemicals we use, policy planners and regulators can help keep everyone safe.

To learn more, Health Canada biologist Jennifer Gibson and her team designed a study that gave Canadian kids the opportunity to participate in a science project, to provide insight on the real-world use of bug sprays containing DEET.

Children between the ages of 7 and 13 years enrolled in overnight summer camps in Ontario during the summer of 2019 (before the COVID-19 pandemic happened and prevented children from attending summer camp in several areas in the country), were invited to join the study, which monitored their use of bug spray as part of their normal camp routine. The study was approved by the strict terms of the Health Canada Research Ethics Board and the participants’ parents.

This was particularly valuable since studies conducted in controlled conditions, for example in a well-ordered lab, may not provide a complete picture. By designing the study around the actual use of bug spray by kids in an ordinary summer camp environment, the project was able to add real-world conditions to the existing data. And, as an added bonus, it got children excited about participating in a real project to advance science!

Children who agreed to participate received a specially designed journal to record the time of each bug spray application, where it was applied, and what activities they were enjoying at the time. They also provided urine samples for the 24-hour study.

“We spent a lot of time developing the materials so they’d be appealing to the kids, and making sure the project wasn’t going to be a burden on their time at camp. We were very aware that the kids’ first reason for being there was to enjoy camp, and we wanted to make sure they knew that they were in control,” explains Gibson.

The samples collected allowed scientists to measure how much DEET the body typically absorbs through the skin, with children’s normal use of bug spray. The findings suggest that typical children’s real-world use of Health Canada approved DEET-based bug sprays results in only a small amount of DEET being absorbed.

The results from this study, in turn, continue to support the information on Health Canada’s insect repellent site that registered products containing DEET can be used safely when applied as directed and in the right concentration, depending on age.

For Gibson, this study provided a unique opportunity to connect with kids and help them get excited about science, which came with its own rewards and challenges. “All of the participants received certificates designating their status as Junior Scientists. We really wanted them to be engaged, not only to improve the accuracy of the study results, but also to encourage their interest in the process,” says Gibson. “It was an amazing study to work on. I’m quite proud of what we did.”