Insect repellent (DEET-based and alternatives) — safety profile

What is this product?

Insect repellents — principally DEET (N,N-diethyl-meta-toluamide), picaridin (icaridin), IR3535, and oil of lemon eucalyptus (OLE/PMD) — are applied directly to skin and clothing to prevent mosquito, tick, and biting fly contact. DEET (CAS 134-62-3) has been the dominant insect repellent active ingredient since its US military development in the 1940s and EPA registration for consumer use in 1957. DEET is highly effective and has a long safety record at concentrations of 10–30% for consumer use — but it has well-documented dermal absorption, CNS effects at high doses, and specific concerns for children under 2 and for high-concentration or repeated applications. DEET concentrations in consumer products range from 5% (short-duration protection, 1–2 hours) to 100% (extended protection, up to 12 hours) — the higher concentrations offer negligible additional protection beyond 30–50% but dramatically increase dermal absorption and toxicity risk. Children represent the highest-concern population: CDC and AAP guidelines recommend against DEET in infants under 2 months (or under 2 for some formulations), using the lowest effective concentration for children, and avoiding application to children's hands (hand-to-mouth transfer). Permethrin, used for clothing and gear treatment rather than skin, is a different class of repellent with distinct toxicity concerns (neurotoxicant — safe for treated fabric, toxic if applied to skin directly). The current CDC-recommended alternatives to DEET — picaridin 20%, IR3535 20%, OLE with 30% PMD — provide comparable protection with different toxicity profiles.

What's in it

Click any compound name for its full safety profile, regulatory consensus, and exposure data.

Who's most at risk

• Pregnant Women — Dermal absorption of endocrine disruptors; fetal exposure
• Children — Thinner skin, higher surface-area-to-body-weight ratio

How to use it more safely

• Apply to exposed skin and clothing, avoiding hands, eyes, and mouth
• Use lowest effective concentration for duration of outdoor exposure
• Wash treated skin with soap and water after returning indoors
• Reapply every 4-8 hours or after swimming, depending on product type

Red flags — when to walk away

• Applying 100% or 95% DEET products to children — High-concentration DEET (>50%) provides no meaningful additional protection duration over 30–50% DEET for children, but significantly increases dermal absorption and CNS risk in the pediatric population. The case reports of DEET-associated encephalopathy and seizures in children predominantly involve high-concentration products applied repeatedly. Consumer products with 95–100% DEET are marketed for hunting and outdoor use and are available without restriction — they are not appropriate for application to children.
• Spraying aerosol DEET repellent directly onto face — Aerosol DEET spray directed at the face creates inhalation exposure (DEET vapor and propellant alcohol) and mucous membrane contact risk (eyes, lips, nasal membranes). This is a common application error — users spray the product in the direction of their head and neck rather than applying to hands first.

Green flags — what to look for

• Picaridin 20% or EPA-registered OLE/PMD for children; DEET ≤30% applied correctly for adults — Using the lowest effective concentration, applying only to exposed skin, and avoiding hands and face minimize DEET exposure while preserving protection. Picaridin and OLE/PMD alternatives eliminate the high-concentration DEET concern for children. Permethrin-treated clothing provides tick protection for outdoor activities without any skin-applied repellent needed.

Safer alternatives

• Picaridin (20%) — Similar efficacy to DEET with potentially fewer skin irritation reports
• Oil of lemon eucalyptus — Natural plant-based option; effective for several hours with lower toxicity concerns
• Physical barriers (nets, clothing) — Risk-free alternative for sensitive populations; most suitable for controlled environments

Frequently asked questions