This insect spray contains DEET, not to be confused with DDT. DDT is outlawed in most parts of the world because it is highly toxic to wildlife and isn’t that great for people either. DEET, when used appropriately is safe. DEET is also the only effective tick repellent in people. That’s it. Citronella, eucalyptus, peppermint oil, and the rest are not effective. If you are going to be doing outdoor activities in tick infested regions (basically anywhere in the world) you need DEET. The very minor worry about adverse effects are nothing compared to the very real life threatening diseases that ticks carry. It just isn’t worth playing roulette with your health because of concerns over DEET. Ask anyone with Lyme or other tick disease and I bet they will say they wish they had worn repellent. Also note that nothing is 100%. You still must check yourself for ticks after any outdoor activity. Tick borne diseases are going to be the new pandemic especially with climate change. Protect yourself.