Preservative

Sodium Bisulfite

Reviewed by Rosie · Last updated 18 Aug 2026

Used in acid-type permanent waves to alter hair shape | Less damaging than alkaline permanent waves

What Is Sodium Bisulfite?

Used in acid-type permanent waves to alter the shape of hair. It is less damaging than alkaline permanent waves, but also has limitations regarding how much change it can effect in hair. It can be a skin sensitizer.

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