DEET mosquito repellent has been used safely for 60 years, sparing millions of users from mosquito bites and mosquito-borne diseases (rare in the USA but not elsewhere). If you have a 12 month old child that weighs 20 pounds, do not put a whole, large bottle of pure DEET on him or her: that is how it causes seizures and/or death (unfortunately this has actually happened a few times). I was a USDA scientist at the lab where DEET was discovered in 1954. So far as know, problems have not been documented with reasonable use. Yes, DEET (more than the ethyl alcohol that it is generally dissolved in) happily dissolves glue, paint and many plastics. [What is DET????]