The first time I used permethrin, it came out of a spray can. I could not read the fine print on the can, so I used it like Off. I used some Canadian deet on my neck, but sprayed the new stuff on my pants while I was wearing them. While hunting, I watched a tick walk up my pants, I was going to burn it with my cigar when it got high enough. Then it simply fell off, stone dead. Time to dig out the reading glasses, nothing can work that good and be safe. If not over done and used properly, it is fairly safe for a neurotoxin.