Sunscreen and bug spray

By HSC Staff Writer • Published: May 4th, 2006
Category: Health in a Heartbeat

Sunscreen and bug spray are one of the all-time dynamic duos when it comes to warding off two pesky problems associated with the otherwise “Great Outdoors.” But scientists warn you might want to think twice before slathering on a product that combines sunblock and the chemical DEET [deet].

In a recent study, University of Florida researchers applied a combination sunscreen and DEET insect repellent lotion to the skin of hairless lab mice. The sunscreen caused DEET to be absorbed into the skin three times faster than DEET alone, rapidly boosting the chemical’s concentration.

The scientists say their findings highlight the need for manufacturers to assess the safety of chemical combinations in skin preparations, not just test ingredients individually. Such studies have especially important implications for children, whose skin surface area is much larger relative to their weight than an adult’s.

Nevertheless, doctors say DEET… developed in the 1950s for use by military personnel and the active ingredient in many of today’s consumer products… has an exceptional safety record. They aren’t advising people to stop using it, particularly because it’s a proven protector against mosquito- and insect-borne illness, such as West Nile encephalitis.

Adverse effects from DEET are rare, and include fleeting headache, irritability and mild confusion.

Still, experts recommend using the chemical sparingly, in the lowest concentration that effectively repels insects. The American Academy of Pediatrics also advises not using DEET on children under two months of age and suggests applying it to older children’s clothing, not their skin.