The Dirt on DEET

The biting bugs of summer bring with them the risk of serious illness and mild annoyance. While DEET, or N, N-diethyl-meta-toluamide, is a good repellent, its safety is regularly called into question. In May a Duke University study found prolonged applications of DEET caused neurological damage in rats, but the author noted that sparing and infrequent use of it on people — for weekend camping trips or outdoor barbecues — could be harmless. The Environmental Protection Agency says DEET is safe if used properly. So, what's properly?

Use products with less than 30% DEET Most experts agree that for adequate protection, adults need no more than 10% to 30% DEET, found in most OFF!, Cutter and Repel products. As a rule, the more DEET a repellent has, the longer it lasts, but one with 30% DEET can last up to six hours. Bug sprays such as Ben's 100 or Repel 100, with up to 100% DEET, are generally advisable only in such heavily infested areas as Alaska or the Florida Everglades.

Use less DEET on kids Repellents, even kid-friendly ones like OFF! Skintastic or Cutter Skinsations, should not be used on children under 6 months. Don't let children apply DEET-based products themselves, and don't use anything with more than 10% DEET.

Don't use sunscreens that contain DEET Products such as Repel Sun & Bug Stuff sound like a great idea, but sunscreen is supposed to be slathered on often and DEET used sparingly. Use extra sunblock, too, since DEET may reduce the potency of sunscreen as much as 30%.

Try controlled-release DEET ... Sawyer and Ultrathon make repellents that release DEET slowly, so you get lower concentrations of the chemical with more staying power.

... or no DEET Natural repellents (Bite Blocker and Green Ban) based on such plant extracts as soybean oil, citronella and eucalyptus, aren't as effective as DEET but might be enough for evenings on the porch.