The one chemical that is the most effective at repelling mosquitos is DEET, according to the CDC.
The chemical, N-diethyl-meta-toluamide, is used as the active ingredient in most commercial repellents and is designed to be applied directly to the skin.
Concentration
You may have noticed that DEET products contain various concentrations from 4 percent to 100 percent. Higher concentrations do not mean DEET works better. Instead, the higher the concentration the longer the application will be effective. So a lower concentration might be perfectly fine for a brief time outdoors, while a higher concentration is preferable for longer-term activities like camping.
Safety
According to the Centers for Disease Control and Prevention, using repellents with DEET is not harmful so long as they are used in accordance with the instructions.
Basic precautions:
– Make sure you don't get repellent in your eyes.
– Don't breathe in or swallow DEET.
– Don't put repellent on wounds or broken skin.
– Although DEET can be applied to children over two months old, never apply it to the hands, eyes, or mouth of young children.
– Use only outdoors. Once inside, wash skin with soap and water.
