DEET Insect Repellent
DEET (full name N,N-diethyl-meta-toluamide) is the active ingredient in many popular mosquito repellents. DEET is applied to the skin or used to impregnate fabrics so as to provide protection against mosquito bites. DEET is available in various products, including sprays, liquids, lotions, wristbands, roll-ons, wipes and towelettes.
How Do DEET Insect Repellents Work?
Mosquitoes are not killed by DEET, they are repelled by it, or warded off. They are not put off by the odour of DEET, but while wearing a DEET insect repellent that is actively working, we’re simply not on a mosquito’s radar. Effectively, DEET repellents stop mosquitoes from being able to find us.
DEET works by hindering a mosquito’s ability to detect chemicals given off by human (and other mammals) skin and breath, including carbon dioxide, lactic acid and octenol, although there is some discrepancy in the available literature as to exactly which chemicals are involved.
When mosquitoes are searching for a tasty blood meal, DEET repellent somehow blocks the odorant receptors they use to detect us.
DEET Effectiveness
DEET is sold in variable concentrations (anywhere from 5% up to 100%). Generally the higher the concentration of DEET in a mosquito repellent, the longer it will give protection before reapplication is necessary. Very high concentrations of DEET are only for short term use in malarial areas, when it is inconvenient to reapply it (such as when travelling in tropical rural areas).
On the whole, DEET products are considered to be more effective than mosquito repellents containing natural active ingredients such as citronella. (Although it is worth mentioning that there are natural mosquito repellents on the market that are considered to be very good.)
Natural mosquito repellents may need to be reapplied more frequently than DEET insect repellents in order to maintain protection. It is advisable to use DEET in malarial areas rather than relying on natural protection.
DEET Safety and its Disadvantages
DEET has been rigorously and extensively tested for its effectiveness and safety and is accompanied by decades of research. However, for some people, DEET repellents can be an irritant and cause minor skin reactions.
There have been rare cases of severe adverse reactions to DEET mosquito repellents, but when used carefully and according to instructions, DEET is unlikely to cause harm to the majority of people who use it.
It is especially important to follow safety precautions when using DEET in high concentrations.
- Do not use DEET under clothing
- Wash DEET products off when they are not needed
- Do not apply DEET to sore or broken skin
- Avoid the eyes and mouth
- Do not swallow DEET
- Do not over-apply
- Do not let young children apply it to themselves
- Do not spray DEET insect repellents directly on to the face
DEET has a greasy, oily feel and a chemical smell that some people find unpleasant, and it can be damaging to some fabrics and plastics. DEET-free insect repellents are available.
In any case, with the spread of serious mosquito-carried diseases such as malaria, West Nile virus, yellow fever, dengue fever and Japanese encephalitis, using a mosquito repellent in high-risk areas that is proven to be effective, such as DEET, is surely preferable to catching a serious disease?
Try to judge the concentration of DEET you will need against the risk of catching an insect-borne disease in the part of the world you are travelling to.
Here are some recommended DEET mosquito repellents »