Common Name(s): Borax/borate,emulsification ph adjuster,sodium borate classic

CAS Number: N/a

DESCRIPTION

What It Does: Adjusts formulation ph, buffers at ph 9–10, and reacts with beeswax fatty acids to form sodium soap that acts as the primary emulsifier in classical cold cream and vanishing cream formulations.

Why It's Used: Borax/beeswax is the oldest systematic o/w emulsification system in cosmetics — the in-situ soap formation between borax and beeswax cerotic acid provides a self-emulsifying cream base still used in traditional formulations.

How It Works: Borax (na₂b₄o₇·10h₂o, pka ~9.2) provides alkaline ph 9–10 buffering in solution. reacts with beeswax fatty acids (cerotic acid, c26:0): rcooh + naoh(from borax) → rcoona (soap). the in-situ soap acts as emulsifier for the mineral oil or beeswax oil phase, producing a classic o/w cream without added synthetic emulsifiers.

Typically Found In: Classical cream formulation,traditional cosmetics

TECHNICAL DETAILS

Primary Category: Active ingredient – cosmetic active

Secondary Functions: Skin conditioning

Application Areas:

Typical Concentration Range: 0.1%–1%

SOURCING & ETHICS

Vegan Status: Conditional - supplier confirmation required

Halal Status: Unverified - supplier confirmation required

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier. [audit 2026-07-29 rev2: the record's own source_notes does not assert a non-animal origin, or instructs the reader to verify with the supplier; "yes" asserts knowledge the record does not hold. determination requires shariah-panel sign-off.]

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Borax is restricted in eu leave-on cosmetics (maximum 0.1% as boric acid equivalent due to reproductive toxicity concerns). the traditional borax/beeswax cream is now primarily a historical formulation — modern formulations use dedicated emulsifier systems with better safety margins.

Last Verified: 2026-03-12

Primary Sources: Cosing database,eu borax restriction beeswax emulsification review