Boron compounds are low to very low in toxicity when
inhaled (2). The U.S. Environmental Protection Agency
(EPA) has not required inhalation toxicity studies for boric
• Boric acid is low in toxicity when applied to the skin (1). It is
poorly absorbed in rabbits across intact skin, but damaged
skin experiences increased penetration (7).
• The U.S. EPA classifies boric acid as low to very low in
toxicity for skin irritation (1).
• Data are not available regarding the ability of boric acid to
affect skin sensitivity (1).
• Boric acid is generally low in toxicity for eye irritation. An
exception is a specific boric acid salt, which is highly toxic to
the eye (1).
• In a 90-day study, investigators fed dogs boric acid. At the highest dose, they noted altered blood chemistry, a buildup
of fat in select tissues, and toxicity to the testes (1).
• Researchers fed dogs boric acid in the diet for 2 years and detected no adverse health effects(1).
• Signs of toxicity in laboratory animals poisoned with boric acid include depression, impaired muscle movement,
vomiting, purple-red skin color, and lowered body temperature (6).