Mosquitoes - Personal Protection

 

Mosquito repellents that are applied directly to the skin (can also be sprayed on clothing, window screens etc). Note that on a really hot or humid day, protection may be a little lower than the averages shown. The products listed are those I found compared in research studies[1],[2],[3],[4].

 

DEET (N,N-Diethyl-3-Methylbenzamide) is the Ōgold standardĶ among mosquito repellents, and it has been proven remarkably safe.  The recommended level of DEET for adults is 10-35%. The American Academy of Pediatrics recommends 10-30% DEET for children. DEET is not recommended for infants under 2 months of age. NOTE: DEET can damage plastics; avoid getting it on your watch crystal, sunglasses, or painted surfaces. Avoid getting it on synthetic fabrics like rayon or spandex. 

 

Also, be aware that DEET repellents reduce the effectiveness of sunscreens by as much as one third! So if you want SPF 20 protection, youÕll need to apply a sunscreen with SPF 30 rating.

 

Many products contain DEET, in differing concentrations. Some examples are:

OFF! Skintastic 6.65% DEET provides nearly 2 hours of protection (widely available)

OFF! Deep Woods 23.8% DEET - approximately 5 hours (widely available)

3M Ultrathon controlled release 23.5% DEET spray - about 8 hours (sold at DickÕs)

3M Ultrathon controlled release 34.34% DEET lotion – about 12 hours (sold at Campmor)

SawyerÕs Controlled Release 20% DEET lotion –up to 12 hours (sold at REI)

Skinsations with 7% deet – 5 to over 5-1/2 hours (widely available)

 

Permethrin

repellents containing permethrin (such as SawyerÕs Promethrin, sold at REI; brand name not indicated in research study) should only be applied to clothing or tent fabric.1,3 This chemical is a very effective long lasting insecticide, but should not be used on skin.

 

Products containing natural (plant based) repellents:

Many natural plant oil based products offer protection from mosquitoes; if you are going to be outdoors for extended periods, plan to reapply often. Most plant based repellents start out pretty strong but significantly lose effectiveness over time1. Examples are:

 

Repel Lemon Eucalyptus – company claims up to 6 hour protection, but it may be significantly lower depending on the type of mosquito. Against the Asian Tiger, one study reported over 7 hours[5]. Pretty good protection. (available at REI.) This product is also available with sun block, SPF 15.

Bite Blocker soybean, geranium and coconut oil repellent – 6 hours depending on the formula (spray or lotion). This product maintained a high level of protection for many hours. (sold at Wal-Mart)

Avon Skin So Soft citronella-based - 20 minutes of very good protection; after that time, protection drops to only about 40% protection for up to about 4 hours.

Buzz Away citronella based, with lemongrass & peppermint – almost 2 hours (sold at The VitaminShoppe). A newer version, Buzz Away Extreme, was not tested in the studies I reference. It has soybean and geranium oils (like the Bite Blocker), so it indeed may be more effective.

 

Lemongrass oil, peppermint oil, cedar oil formulas were all found to offer less than ½ hour protection.

 

Are there more natural products on the horizon? The American Chemical Society is studying nepatalactone, the essential oil in catnip (in the tomato family) – it may repel mosquitoes even better than DEET.

 

Other products sold for personal protection:

repellent-impregnated wristbands – offered virtually no protection in scientific testing4.

High frequency sound-emitting devices (often sold as key-fobs) are not effective[6].


[1]Environmental Protection Agency, 2007. The Insect Repellent DEET. Retrieved from  http://www.epa.gov/opp00001/factsheets/chemicals/deet.htm

[2] Centers for Disease Control, 2007. Insect Repellent Use and Safety. Retrieved from http://www.cdc.gov/ncidod/dvbid/westnile/qa/insect_repellent.htm

[3] Fradin, M.S., 1998. Mosquitoes and Mosquito Repellents: A ClinicianÕs Guide. Annals of Internal Medicine, 128(11)

[4] Fradin, M.S., Day, J.F., 2002. Comparative Efficacy of  Repellents against Mosquito Bites. The New England Journal of Medicine, 347(1)

[5] Barnard, D.R., Xue, R-D., 2004. Laboratory Evaluation of Mosquito Repellents Against Aedes albopictus, Culex nigripalpus, and Ochlerotatus triseriatus (Diptera: Culicidae). Journal of Medical Entomology, 41(4)726-730.

[6] Crans, W.J. Products and Promotions That Have Limited Value for Mosquito Control. Retrieved from http://www.rci.rutgers.edu/~insects/proprom.htm