Boric Acid

Boric Acid

AKA “Orthoboric acid, Boracic acid, Borofax, Boron hydroxide, Boric acid (H3BO3), Boron trihydroxide, Basilit B, Three Elephant”

Synthetic

Ingredient Facts

Boric acid

AKA: Orthoboric acid, Boracic acid, Borofax, Boron hydroxide, Boric acid (H3BO3), Boron trihydroxide, Basilit B, Three Elephant

Synthetic · Antimicrobial · EWG: 4

Synthetic

Preservative

Synthetic

Clean

A gentle preservative that helps keep products fresh and stable while maintaining the right pH balance for skin compatibility.

Solubility 10 to 50 mg/mL at 66 °F (NTP, 1992)

Formula

BH3O3

Mol. Weight

61.84

CAS #

10043-35-3, 11113-50-1

Form

Liquid

State

Boric acid is an odorless white solid. Melting point 171 °C. Sinks and mixes with water. (USCG, 1999)

See origin →

Functions

Antimicrobial

Keeps your product from growing bacteria, mold, or yeast. Without these, that jar of cream becomes a petri dish in about a week.

Buffering

Denaturant

Fights Bacteria

Traditional Use

Used in traditional medicine and early 20th-century cosmetics as a mild antiseptic and preservative. Historically employed in skin salves and eye washes, though its use has been restricted in many countries due to toxicity concerns.

Skin Types

●all-skin-types

Best For

General

Melanin-Rich Skin

Suitable

Pregnancy & Breastfeeding Safe

EWG

CIR

Unsafe

Pregnancy

CIR Safety Findings

Not a Sensitizer

medical-approval

all-shades-safe

Concentration Guide

5.0%

0%7%

Reg. Limit

EU regulatory limit: 5.0%. (a) 5% (as boric acid) (b) 0.1% (as boric acid) (c) 3% (as boric acid). (a) Not to be used for children under 3 years of age Not to be used on peeling or irritated skin (b) Not to be swallowed Not to be used for children under 3 years of age (c) Not to be used for chi... Source: EU Cosmetics Regulation (EC) 1223/2009, Annex III (Restricted Substances), Entry 1a.