What it is
Calcium Carbonate is a naturally occurring and widely available inorganic mineral that appears as a fine white powder. In sunscreens it is used to absorb excess oil and sebum, mattify the skin, reduce the appearance of greasiness from oily filters, and contribute opacity or a soft-focus finish. It can also act as a mild bulking agent and help adjust the feel and pH balance of a formula.
Safety & warnings
Calcium Carbonate is considered inert and well tolerated on skin, with low irritation and sensitization potential. As a dry powder it is non-comedogenic in typical use.
Origin & sourcing
Naturally sourced from mineral deposits such as limestone, marble, and chalk, or produced synthetically as precipitated calcium carbonate.
Questions everyone asks
Why is calcium carbonate in my sunscreen?
It is mainly there to absorb oil, mattify the skin, and improve finish, helping counteract any greasiness from the other ingredients.
Does calcium carbonate provide sun protection?
No. It is not a UV filter. It is used for texture, oil control, and opacity, not for blocking ultraviolet light.