Boric acid solutions can be used to treat mild eye infections and external ear infections in both humans and pets. In powder form, boric acid can reduce sweating that leads to foot odor. It helps cure athlete’s foot and vaginal yeast infections.
When mixed with distilled water, boric acid can be used as an antiseptic to treat minor cuts and burns. Boric acid is also an effective insecticide to control cockroaches, termites, fire ants, fleas, silverfish and other insects, and it is considered safe for household use. In the laundry, boric acid helps remove stains. It can be used for deodorizing the bathroom toilet and garbage cans. It also prevents and destroys existing wet and dry rot in timbers. Combined with a carrier, it can be used to treat external wood against fungal and insect attack. Boric acid can be used to make fire green.
Boric acid powder can be added to soil if it is deficient in boron. However, too much boron in the soil is toxic for plants, and boric acid powder applied directly to plants dries them out. It deodorizes garbage cans and toilets, and it's also used in leathermaking and to regulate the pH of swimming pools.
Boric acid is derived mainly from borax, a mineral that forms stubby, white crystals. Large masses of these crystals are generally found around saline lakes and salt pans in deserts.