EcoSMART Wasp & Hornet Killer
The safest wasp killer for the environment is EcoSmart Wasp & Hornet Killer. Unlike other chemically made wasp killers, EcoSmart wasp killer is made with organic ingredients to get the job done. It uses peanut oil infused with phenethyl alcohol which, essentially, first coats a wasps body to prevent oxygen absorption with the peanut oil, while the alcohol additive gets the wasp toxically drunk. Realistically, if you want to humanely kill a wasp, this is probably the way to do it. It dies smiling the whole way. It is also mixed with peppermint oil to deter other wasps from attempting to recolonize the nest once it has been sprayed. Totally organic, safe for you and the environment, the spray only goes out to 18 feet, so you may have to spray and run before the wasps succumb.