What you may have heard
The use of bug spray with DEET can cause cancer.
What science tells us
Much of the concern about insect repellents is with one of its most common ingredients: N,N-diethyl-meta-toluamide, known commonly as DEET. DEET gives bug spray its strong chemical smell, which is used to repel biting insects, such as mosquitos, ticks, and fleas.
The Environmental Protection Agency (EPA) has concluded that DEET is not a human carcinogen. With high exposure levels, such as in a chemical spill, there may be damage to the central nervous system. Additional evidence about cancer risk is unclear.
Laboratory Evidence/Supporting Evidence
Some animal studies have reported an increased cancer risk when exposed to DEET (NPIC). However, several larger studies with long follow up have been conducted on animals which did not show an increase in tumors when exposed to bug spray with DEET (ATSDR).
IARC Carcinogen Classification: Not classified.
How to reduce your risk
Always use insect repellents as directed. Only apply insect repellents to exposed skin and/or clothing, and do not apply near the eyes or mouth. When using sprays, do not spray directly into the face—spray on the hands first, and then apply to the face.
The EPA has approved the use of insect repellents that do not contain DEET. For example, another ingredient in insect repellent and industrial pesticides is permethrin. The Environmental Protection Agency (EPA) concluded that permethrin (and the associated chemicals resmethrin and d-phenothrin) can be used for public health mosquito control without posing unreasonable risks to human health (EPA). These alternatives could give you peace of mind if you would prefer to avoid DEET. The smartphone app Detox Me also has many tips to help you choose safer products.
Insect repellents containing DEET do not have a cancer-causing effect in humans, but alternatives are available that do not contain DEET.
Learn More From These Trusted Sources
National Pesticide Information Center: DEET General Fact Sheet
Roswell Park Comprehensive Cancer Center: Bug spray and cancer
Environmental Protection Agency (EPA): DEET
EPA: Mosquito control
Published: July 7, 2021
Verified/updated: August 22, 2022