Boric Acid and Borates

Safety Information

Expert Panel for Cosmetic Ingredient Safety

The Expert Panel for Cosmetic Ingredient Safety (Expert Panel) has assessed the safety of sodium borate and boric acid on several occasions. In 1983, the Expert Panel concluded that sodium borate and boric acid, in concentrations less than or equal to 5%, are safe as cosmetic ingredients. The Expert Panel also cautioned that cosmetics and personal care products containing free sodium borate or boric acid at this concentration should not be used on infant or injured skin. As part of the scheduled re-evaluation of ingredients according to the Expert Panel’s procedures, the Expert Panel considered available new data on sodium borate and boric acid in 2003 and reaffirmed the above conclusion.


The U.S. Food and Drug Administration (FDA) has reviewed the safety of boric acid and several other borates and approved their use as indirect food additives in components of adhesives, paper and paperboard (21CFR175.10521CFR176.180). The FDA allows sodium borate to be used in denture adhesives considered medical devices (21CFR872.3400).

The EU Cosmetic Regulation was amended on Nov. 27, 2019, to add boric acid, borates, tetraborates, octaborates and boric acid salts and esters to Annex II (Entries 1395 and 1396), the list of substances prohibited in cosmetic products in the EU. The ban includes the following ingredients: disodium octaborate tetrahydrate; 2-aminoethanol, monoester with boric acid; 2-hydroxypropyl ammonium dihydrogen orthoborate; potassium borate (boric acid potassium salt); trioctyldodecyl borate; zinc borate; sodium borate, disodium tetraborate anhydrous (boric acid, sodium salt); tetraboron disodium heptaoxide, hydrate; orthoboric acid, sodium salt; disodium tetraborate decahydrate (borax decahydrate); and disodium tetraborate pentahydrate (borax pentahydrate).


Boric Acid and Borates

What Is It?

Sodium borate and boric acid are colorless or white crystals or powders. In cosmetics and personal care products, sodium borate and boric acid are used in the formulation of a wide variety of product types, including creams and lotions, as well as other bath, hair and skin products.

Why Is It Used?

Sodium borate and boric acid are used as preservatives to protect cosmetics and personal care products from spoilage. They are also used as buffering agents to adjust pH and to minimize the change in the pH of a solution when an acid or a base is added. Sodium borate and boric acid help to keep an emulsion from separating into its oil and liquid components. Additionally, they are used as viscosity-controlling agents to alter the thickness of liquid cosmetics and personal care products.

Scientific Facts

Sodium borate occurs naturally as the mineral tincal, and boric acid occurs naturally as the mineral sassolite. Both sodium borate and boric acid may also be obtained by treating other minerals such as kernite, ulexite and colemanite.