Boric acid is a compound of boron, oxygen, and hydrogen with formula B(OH)3. It is usually encountered as colorless crystals or a white powder, that dissolves in water, and occurs in nature as the mineral sassolite. It is a weak acid. Boric acid is a common form of boron, a naturally occurring element found in different minerals. Natural sources include: water volcanoes sea salt spray rocks and soil dust food, such as fruits and vegetables Boric acid and borates have been used since the time of the ancient Greeks for cleaning, preserving food, and other activities. It can be found in everyday items, such as: cosmetics pesticides cleaning products swimming pool and spa chemicals drugs and natural health products Canadians are already exposed to boric acid in their diet. You should reduce your exposure from other sources to avoid overexposure. Boric acid is only poisonous if taken internally or inhaled in large quantities. For a 70 kg adult, 350 g could produce death. Long-term exposure to boric acid may be of more concern, causing kidney damage and eventually kidney failure. Acids | Resources HTML & design by Bill Willis 2025