UF/IFAS Mosquito Expert: Literature Review Verifies Safety of Popular Repellent DEET, Counters Alarmist News Reports
As summer continues, many Florida residents find themselves targeted by mosquitoes, biting flies and ticks – and a University of Florida Institute of Food and Agricultural Sciences entomologist says that when people reach for repellents, their first choice should still be products containing the active ingredient N,N-diethyl-meta-toluamide, better known as DEET.
Toxicologist Jeffrey R. Bloomquist, a professor with the UF/IFAS entomology and nematology department and the UF Emerging Pathogens Institute, examined the potential human health impacts of DEET in a short review article co-authored with Daniel Swale, an insect physiologist at Louisiana State University. The authors concluded that DEET-containing products are safe for the overwhelming majority of people when used according to label directions.
The review was published in March by the journal Pest Management Science; Bloomquist is a member of the journal’s executive editorial board.
“We examined some of the latest literature because we wanted to address questions that had been raised in news reports, which suggested that DEET might harm the human nervous system,” Bloomquist said. “The literature indicates that DEET has very low potential to do so, and the average person would have to be exposed to large quantities of DEET to become seriously ill.”
Because some mosquitoes and ticks transmit diseases to people – such as Zika virus and Lyme disease – the use of a repellent could make the difference between a person staying healthy or becoming infected, said Swale, an assistant professor with the LSU entomology department.
“Unfortunately, some news coverage of DEET has had an alarmist tone, and some stories have contained inaccurate or conflicting pieces of information,” Swale said. “These factors may have led some people to refrain from using DEET, and put themselves at greater risk of contracting an arthropod-borne pathogen and becoming ill.”
Bloomquist pointed out that Southeastern residents should be especially diligent about repellent use, because the warm weather is conducive to larger pest populations and pest activity during a greater part of the year. He notes that DEET is often used in lotion-type formulations, and the most commonly reported adverse reaction to DEET is skin irritation at the application site.
“If you notice any redness, itching or pain when you apply a DEET product, you should discontinue use of that product,” he said. “It may be that you have a sensitivity to DEET and need to try repellents with a different active ingredient. But if you’ve used DEET before and had no problems with it, our findings indicate that there’s no reason to start looking for a different option now.”
The mission of the University of Florida Institute of Food and Agricultural Sciences is to develop knowledge relevant to agricultural, human and natural resources and to make that knowledge available to sustain and enhance the quality of human life. With more than a dozen research facilities, 67 county Extension offices, and award-winning students and faculty in the UF College of Agricultural and Life Sciences, UF/IFAS works to bring science-based solutions to the state’s agricultural and natural resources industries, and all Florida residents. Visit the UF/IFAS web site at ifas.ufl.edu and follow us on social media at @UF_IFAS.