So there is a bit of common sense that must be inferred from the claim of "SAFE NON-TOXIC". But if it still has the potential for harm is it okay to sell it? The same chemicals that are in goop are also found in some clothing, rubber shoes, cosmetics & perfumes, plastic food containers, plastics in your car, plastic IV bags at the hospital, playground equipment, etc. The message-I wouldn't eat or smoke those things either.
I sell my goop only to adults with thought that they are responsible enough to educate their children about chemical safety. Just like after playing in the dirt, fixing a bike, or playing with paint, you should wash your hands after using (liquid) goop. Goop is not water soluble and so you do need to use lots of soap. Goop can stain and damage some materials if not cleaned up. The plasticizer in goop will soften polystyrene(styrafoam) to the point where it dissolves. The plasticizers might damage other things like the varnish on wood if it is left in contact for extended periods. I find concentrated dish soap best at cleaning up goop. First work in the dish soap, and then add some water to carry the soap and goop away. The message-Goop is a chemical compound, treat it like one.