How long does deet work




















Two separate studies—one in New Jersey women and one in Thailand women —found that while deet molecules can cross the placenta and enter the womb, they do so in very small concentrations. In both studies, babies born to mothers who used deet were not smaller or sicker and did not suffer from cognitive deficits or any major birth defects compared with babies born to mothers who did not use the chemical.

For the most part, yes. But according to the CDC, the chemical is broken down by sunlight and by other chemicals in the air. In 5 hours time, one-half of the deet released into the atmosphere will disappear this way.

The deet on your skin is most likely to end up in aquatic systems, because when you shower, bathe, or wash your clothing, the chemical slips from your skin and clothing into the water supply. In water, deet is degraded by aerobic microorganisms. In general, it does not stay in the environment for very long.

As with all insect repellents, the key to using deet-based products safely is to follow product instructions and take basic precautions:. Use the right concentration. Research shows that the concentration of active ingredient has an impact on how long the compound lasts, not on how well it works. Our testing indicates that products containing 25 to 30 percent deet typically provide at least several hours of protection.

Any more than that and you're increasing your exposure without improving the repellency. Apply the repellent properly. Instead, spray it on your hands, then rub it on your face. Also, repellent should be applied only to exposed skin, not to skin that will be covered by clothing. The best way to do that is to spray the clothing on a hanger and let it dry before putting the clothes on.

And just to be safe, you should wash the repellent off your skin when you come back indoors for the day or at the very least before bedtime. Know when not to use it. You want to skip it for children younger than 2 months old. The CDC advises protecting babies that young by draping mosquito netting with elastic edges around their strollers or carriers.

Picaridin Picaridin is a repellent that was modeled after a molecule found in pepper plants. It has been on the U. Specifically, spray products with at least 20 percent picaridin have worked as well or better than some deet-based ones.

Not as much research has been done on picaridin as on deet. But the data that does exist indicate that the chemical is safe, and the World Health Organization and the CDC recommend picaridin. OLE is registered with the EPA as a biopesticide , meaning that products containing this ingredient are subject to at least some testing for safety and efficacy.

To be sure, the requirements for biopesticides are more lax than they are for synthetic products like deet and picaridin: OLE is not recommended for children younger than 3.

Bug bites are not only annoying, they can also transmit diseases. On the ' Consumer ' TV show, host Jack Rico goes inside Consumer Reports' labs to find out how CR tests insect repellents to make sure you are getting the most protection. We respect your privacy. All email addresses you provide will be used just for sending this story.

How Safe Is Deet? By Jeneen Interlandi. The annual number of people sickened by mosquitos or tick bites has more than tripled since , according to the CDC.

The World Health Organization has concluded that climate change is a likely contributor to these increases, which are predicted to continue as warmer global temperatures expand the habitats of mosquitos, ticks and other disease-spreading bugs.

For all of these reasons, more and more people are looking for safe and effective ways to keep biting bugs at bay. DEET seems to work in a similar fashion on ticks, although the exact mechanisms by which DEET repels bugs is a point of debate among researchers.

Day calls DEET the gold standard of repellants, and one that is nearly always harmless when applied appropriately.

Still, DEET has a scary reputation. Day says this stems from several cases from the s of people dying after drinking DEET. Also, thanks to their similar handles and applications, DEET is sometimes confused with DDT, a now-banned chemical insecticide that can promote cancer and birth defects. There have also been scattered research reports tying DEET to health concerns. One study concluded that DEET may prevent the normal breakdown of acetylcholine, a nervous system chemical that triggers movement and muscle activity.

Some older research has also tied DEET to seizures or brain toxicity in children. Studies on the use of DEET among pregnant women have failed to find any harmful effects. DEET can also cause temporary numbness if it gets onto your lips or into your mouth. To use DEET properly, spray it on your hands first, and then rub it on the parts of your body you wants to protect and that mosquitos like to bite—like ankles, wrists and neck. The mosquitoes, they found, were still happy to land on the skin, puncture through it , and drink the clean blood beneath.

Third, they offered the mosquitoes a serving of warm blood protected by a skin-like membrane. When the DEET or other bitter substances were mixed into that blood, they found, the mosquitoes didn't drink it. Fourth, they tested those compounds on the surface of the membrane with clean blood beneath. Bitters on the membrane weren't effective at stopping the insects from drinking.

But with a layer of DEET on the membrane, the mosquitoes still landed on it but immediately took off. Fifth, they offered the mosquitoes blood beneath a patch of DEET-coated skin that was too small for them to simultaneously drink from and touch with their legs. The mosquitoes still drank, suggesting that they weren't just reacting to the way DEET felt to their mouthparts.



0コメント

  • 1000 / 1000