Science
Mechanism of Action
This ingredient functions to maintain the stability and efficacy of cosmetic formulations through several mechanisms. It serves as an emulsifier, a pH regulator (due to its inherent alkalinity), and a preservative, often boosting the effectiveness of other preservatives. Sodium Borate also acts as a water softener, stabilizer, buffer, and viscosifier. On the skin, its mild antiseptic and anti-fungal properties, coupled with gentle exfoliating potential, may aid in managing skin pH, preventing extreme dryness or oiliness, and helping to unclog pores.
Research
Clinical Evidence
Medium confidenceN/A
Key findings
- 01 Demonstrated to be non-irritating to moderately irritating and non-sensitizing on human skin when incorporated into certain cosmetic formulations.
- 02 Formulations containing these concentrations yielded negative results in photopatch testing, indicating no photo-irritation or photo-sensitization.
- 03 A cleansing cream formulation caused no irritation in 100 subjects in one panel. A 21-day cumulative irritation test resulted in slight erythema in 2 subjects with a total irritancy score of 6.4, generally considered non-irritating.
- 04 A hair preparation formulation induced erythema and papules in most subjects during a 21-day cumulative irritation test, achieving a total cumulative irritancy score of 571 out of 630, indicating significant irritation.
Transparency
Dusting Analysis
Sodium Borate presents significant safety concerns, including systemic exposure and reproductive health risks, leading to its classification as a Category 1B reproductive toxin in the EU. Its use is strictly limited to rinse-off products at concentrations below 5% and is explicitly banned in leave-on cosmetics in the EU. Any application exceeding these stringent guidelines, particularly in leave-on formulas, on infant skin, or on compromised skin, constitutes a critical misuse with potential for serious adverse effects, making it a commonly 'dusted' ingredient in terms of improper application.
The Formula
Formulation
Stability
Sodium Borate exhibits a strong alkaline nature, with an inherent pH generally ranging between 9 and 11. This alkalinity is a critical factor in formulation, requiring careful pH adjustment to prevent potential skin irritation.
Conflicts
- Damaged or injured skin
- Infant skin
- Leave-on cosmetic products (EU regulations)
- High concentrations, due to potential for irritation
Safety
Safety Profile
The CIR Expert Panel's amended assessment concluded Sodium Borate is safe only in rinse-off products, at concentrations below 5%, and when formulated to be non-irritating. This is primarily due to systemic exposure and reproductive health data. It is contraindicated for use on infant or injured skin, as it is absorbed more readily through compromised skin. The EU has classified Sodium Borate as a Category 1B reproductive toxin, banning its use in leave-on cosmetic products and imposing tight concentration limits (e.g., max 5%) in rinse-off items. In the US, it is permitted by the FDA but remains under scrutiny, and Canada also enforces usage restrictions.
Your Skin
Skin Compatibility
Our Assessment
Verdict
While offering various functional benefits in formulations, Sodium Borate presents significant safety concerns, including reproductive toxicity and irritation potential, severely limiting its appropriate application to specific rinse-off products at very low concentrations, making its general use questionable for precision skincare.
Related
Similar Ingredients
Finding similar ingredients…