The acute median lethal dose for boric acid in humans is estimated to be several grams per kilogram body weight, which is not very toxic. Chronic consumption in

The acute median lethal dose for boric acid in humans is estimated to be several grams per kilogram body weight, which is not very toxic. Chronic consumption in lower doses may cause kidney problems. As pesticides go, it appears to be pretty safe. It's probably a good idea to wear an N95 mask when applying it, apply it in areas where it won't be easily disturbed, and make sure it doesn't contaminate food or water.