Ingredient dictionary

Sodium Sulfite

Sodium sulfite is a white powdered salt whose main job is acting as an antioxidant, slowing the breakdown of other ingredients exposed to air. It is on the label of 2 products in our library. Checked against our library November 6, 2026.

What Sodium Sulfite does

Slows oxidation in oils and extracts
Helps keep dye colors stable
Acts as a reducing agent in hair products

Sodium sulfite is made in factories by reacting sulfur dioxide with sodium-based chemicals. It also has many industrial uses outside cosmetics.

Formulators add it mainly as an antioxidant. It takes up oxygen before oxygen can damage oils, extracts and dye ingredients. In some hair straightening and perm products, it works as a reducing agent, helping break the bonds that give hair its shape. It dissolves easily in water and has little smell or feel of its own.

Good for

Formulas with oils, extracts or dyes that can slowly oxidize and change color or scent over time.

Frequently asked questions

Is sodium sulfite safe in skincare?

It is used at low levels in cosmetics and is generally considered well tolerated. Most people have no trouble with it. If you have a known sulfite sensitivity, which is most often linked to food or drinks, do a patch test first.

Is sodium sulfite the same as sodium sulfate?

No. They are different salts with different jobs. Sodium sulfite is the one that works as an antioxidant. Check the exact spelling on the label, since the two names look similar.