AMMONIUM BISULFITE is graded C (Moderate) by Expert·ING, based on COSING regulatory data. It is restricted under EU COSING — AnnexIII-SAFETY-.
AMMONIUM BISULFITE
Safety grade: C
This preservative is permitted in EU cosmetics up to a maximum concentration under EU Cosmetics Regulation (EC) No 1223/2009. To be sold legally in the EU or UK, a product must stay within this limit.
This ingredient is used in hair treatment products to soften and restructure hair fibers during waving or straightening processes, while also helping preserve the product by preventing oxidation.
Graded using: COSING.
- EU COSING — Restricted
- EU COSING — Restricted use
Last verified: June 9, 2026
Safer alternatives to AMMONIUM BISULFITE
- SODIUM METABISULFITE — Grade B. Reduces disulfide bonds in hair; preserves product through antioxidant action.
- THIOGLYCERIN — Grade A. Breaks keratin disulfide bonds for hair straightening/waving; reduces oxidation.
- STANNOUS CHLORIDE — Grade A**. Reduces agent that breaks disulfide bonds for permanent hair restructuring.
Other Preservative ingredients
- SODIUM BENZOATE — Grade C
- PHENOXYETHANOL — Grade B**
- BENZYL ALCOHOL — Grade C**
- POTASSIUM SORBATE — Grade B
- BENZOIC ACID — Grade C**
- METHYLISOTHIAZOLINONE — Grade C
- METHYLPARABEN — Grade C
- SALICYLIC ACID — Grade C**