Chemical Formula: H3BO3

Also called: Orthoboric acid, boric oxide, boron oxide.

Boric acid in industry is used mainly making glass products, like glass fiber, glaze, and enamel. It’s used as an ingredient in flame retardants, corrosion inhibitors, and adhesives.

We regular people have some pretty good uses for it too, such as pest and fungal control. It can be found as an ingredient in products reputed to kill fleas, ants and cockroaches. It’s a desiccant, which means it absorbs moisture. The pest will walk through the fine powder and carry it back to the nest, rubbing against other bugs. The powder dehydrates everything it touches. Applied to wood, it prevents fungi from retaining moisture and is an excellent preservative.

Many advocates of natural remedies recommend boric acid for the relief of cold sores and vaginal yeast infections. One study showed the application of an ointment containing this compound to reduce the length of a cold sore outbreak from six days to four on average. Another study found that out of 100 women who were resistant to over the counter yeast infection remedies, 98 percent had success with a two week treatment of a boric acid suppository.

Though it may sometimes be beneficial, boric acid is still toxic and should never be taken internally. Most cases of poisoning occurred from ingestion of talcum powder, which often contains this material. Symptoms of poisoning include skin irritation, nausea, vomiting, diarrhea, decrease in urine, twitching of extremities and convulsions, and low blood pressure. Poisoning can lead to kidney or respiratory failure, coma or death.

References:, Medline and the National Library of Medicine, Mother, Michael R. Cartwright, Sr.