Sodium Borate

Synonyms: Borax decahydrate; boric acid disodium salt; E285; natrii tetraboras; sodium biborate decahydrate; sodium pyroborate decahydrate; sodium tetraborate decahydrate.

Description: Sodium borate occurs as white, hard crystals, granules, or crystalline powder. It is odorless and efflorescent.

Chemical Name: Disodium tetraborate decahydrate

Alkalizing agent; antimicrobial preservative; buffering agent; disinfectant; emulsifying agent; stabilizing agent.

• Sodium borate is used in pharmaceutical applications similarly to boric acid (see Boric Acid).

• It has been used externally as a mild astringent and as an emulsifying agent in creams.

• It has also been used in lozenges, mouthwashes, otic preparations (0.3% w/v), and ophthalmic solutions (0.03–1.0% w/v).

• Sodium borate has additionally been investigated in the prevention of crystal formation in freeze-dried solutions.

• Preparations of sodium borate in honey have historically been used as paints for the throat, tongue, and mouth, but such use is now inadvisable because of concerns about toxicity in such applications

• . Sodium borate is also used in cosmetics such as moisturizers, deodorants, and shampoos.

Sodium borate is incompatible with acids and with metallic and alkaloidal salts.

Sodium borate has weak bacteriostatic and astringent properties. Historically, sodium borate has been used as a disinfectant in skin lotions and eye-, nose-, and mouthwashes. However, boric acid is easily absorbed via mucous membranes and damaged skin, and severe toxicity has been observed, especially in babies and children. Consequently, the use of sodium borate as a disinfectant is now considered somewhat obsolete and careful use is recommended. The toxic effects of sodium borate include vomiting, diarrhea, erythema, CNS depression, and kidney damage. The lethal oral intake is approximately 20 g in adults and 5 g in children.

Observe normal precautions appropriate to the circumstances and the quantity of material handled; do not combine with acids.

Boric acid; sodium borate anhydrous.