The taste of boric acid is slightly bitter and sweet. It has a slippery feel when in contact with the skin. There is no change in the exposed air. It can volatilize with water vapor. When boric acid is heated to 100-105 ° C, one molecule of water is lost to form metaboric acid, which is converted to pyroboric acid by heating for a long time at 104-160 ° C, and an anhydrate is formed at a higher temperature. The pH of the 0.1 mol/L aqueous solution of boric acid was 5.1. 1 g of boric acid can be dissolved in 18 ml of cold water, 4 ml of boiling water, 18 ml of cold ethanol, 6 ml of boiling ethanol and 4 ml of glycerol. Its solubility in water increases with the addition of hydrochloric acid, citric acid and tartaric acid. The relative density of boric acid is 1.4347. The temperature of 184 ° C (decomposition). The boiling point of 300 ° C. The median lethal dose of boric acid (rat, oral) is 5.14G/KG. Boric acid is irritating and toxic. Death is caused by severe oral administration. The minimum lethal dose: 640mg/kg for adults, 8.6g/kg for skin, 29mg/kg for intravenous use, and 200mg/kg for infants. The maximum allowable concentration of boric acid in the air is 10 mg/m3.
The theoretical composition of boric acid is boron oxide (B2O3) (chemical formula for boron oxide) and water. It is a white crystal that can be made into granules or powder. Both forms are stable under normal conditions. They have fluidity and can be easily transported by air or mechanically. And the solution is slightly acidic. It is a very weak acid, and the acidity of boric acid increases when glycerin is added to boric acid. The borate ester it forms burns to produce a green flame that can be used to identify boron-containing compounds（physical properties of boric acid）.
Boric acid should be stored in a dry and clean warehouse, and should not be stacked in the open air. Avoid rain or moisture. It should be transported in a car, cabin or covered car. It should not be mixed with wet and colored materials. The vehicle must be dry and clean.
Boric acid is mainly used as an industrial raw material for glass, enamel, porcelain, and medicine. Boric acid is a pure, multifunctional boron oxide-containing material. Like borax, boric acid is an extremely versatile industrial boride.