Calcium Sulfate Hydrate

What is Calcium Sulfate Hydrate?

Calcium Sulfate Hydrate is an inorganic mineral compound, primarily the dihydrate form of calcium sulfate (CaSO4·2H2O), sourced from natural gypsum deposits. This fine, white powder appears in exfoliating scrubs, facial cleansers, makeup powders, and toothpaste formulations. It functions through physical action: as an abrasive, it polishes the skin surface by dislodging dead cells during mechanical rubbing; as an anticaking agent, it absorbs excess moisture to maintain free-flowing powders; it offers a subtle tightening sensation by interacting with skin proteins; it binds components for product stability; it aids in pigment lightening via mild oxidative effects in specific blends; it reduces transparency for a creamy appearance; and it supports skin suppleness by facilitating even application and residue minimization. Valued for its stability and inertness in water-based and dry products.

Comedogenic Rating 0/5 Low risk of clogging pores
EWG Safety Rating 1 View on EWG →
PubChem View on PubChem →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Abrasive
Provides gentle mechanical exfoliation and polishing, helping remove surface dead skin cells and improve smoothness and slip in scrubs and cleansers.
Anticaking agent
Prevents powders from clumping by reducing moisture pickup and improving flow, keeping loose and pressed powders uniform during storage and use.
Astringent
Creates a temporary tightening and toning effect by contracting surface proteins, helping reduce the look of oiliness and refining feel on skin.
Binding
Provides cohesion by helping ingredients stick together, improving the strength and integrity of pressed powders, tablets, or solid bars.
Bleaching
Lightens color by chemically breaking down pigments (typically via oxidation), used in hair lightening systems and some stain-removal or brightening applications.
Opacifying agent
Makes a formula less transparent to create a creamy, opaque look; can also help visually mask suspended particles and improve aesthetic uniformity.
Skin conditioning agent
Maintains skin softness, smoothness, and flexibility.

Benefits

Supports gentle surface polishing for improved skin texture.

Enhances powder flow and uniformity in makeup and dry formulations.

Provides a refined, toned feel with minimal residue.

Who It's For

A quick guide for who this ingredient may suit (and who should be cautious).

Who May Benefit Who Should Avoid
Individuals seeking mild exfoliation in cleansers or scrubs.
Those with known mineral sensitivities or allergies.
Users of loose or pressed powders for better application.
Individuals with compromised skin barriers like open abrasions.
People wanting a temporary smoothing effect in daily routines.
Users prone to inhaling fine powders during application.

Safety Notes

  • Rated low hazard by safety assessments for cosmetic use.
  • Non-comedogenic and unlikely to clog pores.

Frequently Asked Questions about Calcium Sulfate Hydrate

Is Calcium Sulfate Hydrate safe for daily use?

Yes, it is considered safe in cosmetics at typical concentrations with low irritation potential.

Does it clog pores?

No, it has a comedogenic rating of zero, making it suitable for acne-prone skin.

What products contain it?

Common in scrubs, cleansers, powders, and toothpaste for exfoliation and texture.