Sodium Borate

The Food and Drug Administration (FDA) has reviewed the safety of Boric Acid and approved its use as an indirect food additive as a component of adhesives and paper and paperboard.

The safety of Sodium Borate and Boric Acid has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The CIR Expert Panel evaluated the scientific data and concluded that Sodium Borate and Boric Acid, in concentrations less than or equal to 5%, are safe as cosmetic ingredients. The CIR Expert Panel also cautioned that cosmetics and personal care products containing free Sodium Borate or Boric Acid at 5% should not be used on infant skin or injured skin. In 2003, as part of the scheduled re-evaluation of ingredients, the CIR Expert Panel considered available new data on Sodium Borate and Boric Acid and reaffirmed the above conclusion.CIR Safety Review: Investigators have reported that Sodium Borate and Boric Acid are poorly absorbed through intact skin. Both compounds are absorbed through abraded, denuded or burned skin. In a 90-day dermal toxicity study, Boric Acid (25-200 mg/kg/day) was nonirritating and nontoxic when applied to intact skin. Sodium Borate and Boric Acid were relatively nontoxic when tested orally. A 5% Sodium Borate water solution was mildly or moderately irritating to the skin, and practically nonirritating when instilled in the eyes. Acute studies indicated that, at 10% in water, Boric Acid was mildly or moderately irritating to the skin.

Sodium Borate or Boric Acid in the diet caused growth retardation. Dose levels of Boric Acid much higher than in personal care products caused reproductive effects. Boric Acid was nonmutagenic in a bacterial test system. Boric Acid induced genetic effects in fruit flies. Limited carcinogenic and developmental toxicity studies did not indicate any effects.

In clinical studies, cosmetic products containing up to 3.2% Sodium Borate were nonirritating to moderately irritating and nonsensitizing when applied to human skin. Formulations containing up to 2.4% Boric Acid were moderately irritating and practically nonirritating. Photopatch testing of formulations containing 1.1% or 1.7% Sodium Borate were negative.

Link to FDA Code of Federal Regulations for Boric Acid
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRS...
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRS...

The FDA allows Sodium Borate to be used in denture adhesives that are considered medical devices.
Link to FDA Code of Federal Regulations for Sodium Borate
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRS...

Both ingredients are listed in the Cosmetics Directive of the European Union under Boric Acid, borates and tetraborates, and may be used in talcs, products for all hygiene, and other products excluding bath and hair waving products, at concentrations up to 5%, 0.1% and 3%, respectively. Sodium Borate and Boric Acid are not to be used on peeling or irritated skin or in cosmetics and personal care products for children under 3 years of age.
Link to the EU Cosmetics Directive: http://ec.europa.eu/enterprise/cosmetics/html/consolidated_d...

The Joint FAO/WHO Expert Committee on Food Additives has determined that it was not necessary to allocate an Acceptable Daily Intake for Boric Acid. http://www.inchem.org/documents/jecfa/jeceval/jec_226.htm