Insect repellents containing DEET are the most effective and the most commonly used world wide. DEET has been available commercially for over 50 years and has been studied extensively.
It is thought that DEET works by interfering with the mosquito antennae function, effectively making humans invisible to the mosquito. Generally, the duration of protection is related to the concentration of DEET. However, at a concentration of 50%, this effect plateaus. 30% DEET is the lowest effective dose.
DEET repellents have a very good safety record, when used as directed. When DEET is applied to the skin, some is absorbed into the circulation. However, if the same amount of DEET were to be taken by mouth, either accidentally, or non-accidentally, blood concentrations will be hundreds of times higher and seizures and death can result. Toxic effects have most often occurred as a result of ingestion, rather than skin application. Repellents should not be applied to the lips, mouth, sunburned skin, damaged skin, or deep skin folds, and hands should be washed after applying DEET.
The risk of disease due to the bite of an insect is far greater than the risk involved in applying DEET insect repellents to the skin. 30% DEET repellents are safe to use and are recommended for adults, pregnant women, breast-feeding women and children over 2 months of age.
