What Is Calcium Sulfate?
Calcium sulfate, also called calcium sulphate or CI 77231, is a naturally occurring mineral made up of calcium, sulfur and oxygen. The most common source is gypsum rock, which forms when seawater evaporates and leaves mineral deposits behind. People have worked with gypsum for thousands of years, first turning it into plaster for building and artwork, then later refining it for many modern uses.
To get cosmetic-grade calcium sulfate, miners extract gypsum, crush it and heat it to remove excess water. The resulting powder is milled, filtered and checked for purity so it meets safety and texture standards for personal care products.
Formulators value calcium sulfate for its versatility. You will often find it in face masks, exfoliating scrubs, toothpaste, pressed and loose powders, foundations, setting powders, bath bombs and some hair styling products where it helps control texture and finish.
Calcium Sulfate’s Cosmetic Benefits/Uses
Calcium sulfate contributes to a formula in several practical ways
- Abrasive: Its fine particles provide gentle scrubbing power that helps lift away dead skin cells or surface stains on teeth without harsh scratching
- Bulking: It adds body to powders and creams, allowing a product to reach the desired weight and feel without changing its active ingredient levels
- Opacifying: By scattering light it reduces transparency, giving products a soft matte look and helping to mask skin imperfections when used in makeup
Who Can Use Calcium Sulfate
Because calcium sulfate is an inert mineral with no active chemicals that penetrate skin it is generally considered suitable for all skin types, including sensitive or acne-prone skin. Its particles sit on the surface and are rinsed away so they rarely trigger flare-ups
The ingredient comes from gypsum rock, not animals, and no animal-derived processing aids are needed. This makes it appropriate for vegetarians and vegans
Pregnant or breastfeeding women can usually use products containing calcium sulfate since it is not absorbed through skin in any meaningful amount. This is not medical advice and anyone who is pregnant or nursing should still show the full product list to a doctor to be safe
Calcium sulfate does not make skin more prone to sunburn and does not react with sunlight, so no special daytime precautions are needed beyond normal sunscreen use
Potential Side Effects/Adverse Reactions
Reactions to topical calcium sulfate differ from person to person. The following are potential side effects but most users will not experience them when the ingredient is used in a properly formulated product
- Mild skin irritation very rare tingling or redness, usually if skin is already compromised
- Dryness or tightness if an exfoliating scrub with calcium sulfate is rubbed too vigorously or left on too long
- Eye irritation if loose powder accidentally gets into the eyes during application
- Respiratory discomfort temporary coughing or throat scratchiness from inhaling airborne powder while using loose products
If any discomfort or reaction occurs stop use immediately rinse the area with water and seek medical advice if symptoms persist
Comedogenic Rating
Rating: 0 / 5
Calcium sulfate particles stay on the surface then rinse or wipe away so they do not clog pores or trap oil. They are also chemically inactive which means they will not trigger excess sebum production. For these reasons the ingredient earns a solid 0.
That makes calcium sulfate perfectly fine for people who are prone to acne or breakouts.
Only loose powders carry a small risk of settling into pores if left on overnight so always cleanse at the end of the day.
Summary
Calcium sulfate acts as a gentle abrasive to lift away dead cells, a bulking agent that gives products the right weight and feel, and an opacifier that softens shine for a smooth matte finish. Its mineral nature lets it handle these jobs without reacting with other ingredients or the skin itself.
The ingredient is not a headline grabber like hyaluronic acid or vitamin C but it quietly shows up in plenty of everyday items from face masks to setting powders because it is reliable, affordable and easy to source.
Overall safety is high, with very low reports of irritation, no pore clogging and no known long-term risks. As with any new product, do a quick patch test first to make sure it plays nicely with your unique skin.