A mosquito-repellent wristband works by emitting vapours that fend off insects. Wristbands that repel insects are doused in relatively harmless chemicals and can offer some protection around the immediate area.
Chemicals used on bug-repelling wristbands include citronella, DEET and geraniol. DEET is one of the most popular pesticides in the United States and has been deemed safe by the EPA when used as directed. In laboratory testing, citronella shows little or no toxicity to humans, but may cause skin irritation. Geraniol could cause an allergic reaction, as well as eye and skin irritation.
Geraniol is an alcohol derived from plant oils and is known to prevent bites from mosquitoes, fire ants, fleas, gnats, ticks and other insects. It was the first effective alternative to pesticides containing DEET.
Oil of citronella, which is derived from two types of dried grass, has been used for more than 50 years as an insect repellent. Citronella does not harm or kill insects, but its aroma interferes with the insect's ability to locate a host.
In one test conducted by a researcher at the Institute of Environmental and Human Health, a volunteer wearing a citronella-soaked wristband received five mosquito bites. On her unprotected arm, she received 14 bites. In an unofficial test of geraniol-soaked wristbands, volunteers reported receiving fewer bites as well.