Safe and Environmentally Friendly Windshield Washer Fluid

Ethyl alcohol. You can buy it at your liquor store. Do not buy denatured ethyl alcohol. It contains 5% isopropyl alcohol, which is poisonous. OTOH, what are you worried about? Who or what is going to drink it? If you are concerned about a child or pet, use the advice given. If it is an environmental concern, forget about it. You can use methyl, ethyl (even denatured) or isopropyl alcohols. They will not poison the environment. But don’t use ethylene glycol because it will kill dogs, even if a small amount drips onto the road. It smells sweet and will attract dogs. They lick, they die.