Human and pets have soft tissue that don’t seem to be bothered by it. I meant inhaling a large amount of fine powder of any type is a problem. Boric acid seems to be pretty heavy that they’re not airborne easily.

Boric acid was used in detergent, pool cleaning, eye wash, mouth rinse, toothpaste, skin treatment, and some food preparation.

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.