All you have to do it is type TETRACHLORVINPHOS into GOOGLE and you will see just how bad this pesticide is. Yet HARTZ puts it in most of their flea products. For example HARTZ Ultra Guard Plus Flea and Tick Spray. Avoid this pesticide and HARTZ in general until they remove this pesticide from all of their products.
I know from personal expeirence that if you get the HARTZ Ultra Guard Plus Flea and Tick spray on your skin it burns and can leave rash marks on your skin that last for days and sometimes weeks. Thier is no point to put this product on a pet that your trying to save from fleas. Your better off giving them a DAWN flea bath. DAWN will not kill the flea eggs but it does kill all the fleas on your pet. You can give your pet a DAWN bath 1 or 2 times per month. DAWN is completely harmless to your pets.