Dr. Mercola corrects this video with a lot of good info:
Currently, DEET (N,N-diethyl-meta-toluamide) is used in hundreds of products, in concentrations of up to an astounding 100 percent. If a chemical melts plastic or fishing line, it’s not wise to apply it to your skin—and that is exactly what DEET does. Children are particularly at risk for subtle neurological changes because their skin more readily absorbs chemicals in the environment, and chemicals exert more potent effects on their developing nervous systems. Based on 30 years of clinical studies, DEET exposure can potentially cause the following adverse health effects:7

Memory loss Headaches Muscle weakness, muscle and joint pain
Impaired brain cell function, neurotoxicity8, 9 Tremors Seizures
Skin irritation, hives, blistering Nausea and vomiting Hypotension
Bradycardia Shortness of breath Pain, irritation, and watering eyes

Another potentially harmful chemical found in many bug sprays is permethrin. This chemical is a member of the synthetic pyrethroid family, which is known to be neurotoxic. The US Environmental Protection Agency (EPA) has also deemed permethrin carcinogenic—capable of causing lung tumors, liver tumors, immune system problems, and chromosomal abnormalities. Pyrethroids have recently been linked to behavior problems in children as well.
Permethrin is very toxic to the environment—especially to bees and aquatic life—and is extremely toxic to cats.10 Even a few drops can be lethal to your feline companion. It is used as an ingredient in some topical flea products, so when you see “for dogs only” on the label, it likely contains permethrin. For more information, please refer to the Environmental Working Group’s (EWG) extensive 2013 review of bug repellant ingredients.11
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