Just be careful when using it as it a powerful toxin. I have used it and it is highly effective and applied it to clothing wearing a mask, gloves and eye protection.
"Several studies done by a team of Duke University researchers lead by Mohammed Abou-Donia suggest that DEET in conjunction with permethrin-impregnated clothing may be linked to Gulf War Syndrome. The symptoms, which affect thousands of veterans from the first Persian Gulf War, include headaches, fatigue, loss of memory, and chronic muscle and joint pain. The researchers exposed animals to the same doses of DEET and permethrin experienced by the war veterans using the same routes of exposure and found neurological damage that lead to motor deficits and learning and memory dysfunction, like the damage characterized by Gulf War Syndrome. "
"For humans, acute toxicity is fairly low, producing systems mainly of irritation. Permethrin can be irritating to both the eyes and the skin. Occupational exposure to permethrin has caused skin sensations that include itching, burning, and numbness, and irritative symptoms in the eyes and upper respiratory tract. To assess the human tolerance, absorption, and persistence of permethrin when used against human lice, 10 adult volunteers were treated with permethrin head louse solution. Three of them developed mild, patchy erythema, which lasted for a few days. In another study to assess the degree the dermal absorption of permethrin from impregnated clothing, volunteers wore military clothing that had previously been treated with an aqueous suspension of permethrin for 48 hours. Volunteers complained of. Additionally, synthetic pyrethroids have been shown to be respiratory allergens and use of them may result in asthma-like symptoms, especially in children with a history of asthma or allergies. Besides asthma, other allergic respiratory responses to permethrin can include sneezing, asthma, sinusitis, and bronchitis."