Zinc Oxide

INCI - Zinc Oxide or CI 77947 when used as a colourant.

What is it - Zinc oxide is a mineral compound commonly used in cosmetic formulations for its sunscreen and skin-soothing properties. It acts as a physical UV filter, providing broad-spectrum protection against both UVA and UVB rays. Zinc oxide is also known for its anti-inflammatory and antimicrobial properties, making it beneficial in products for sensitive skin, acne treatments, and nappy rash creams.

pH - Presence of zinc oxide shifts formulas to pH 7.5.

Safety limit - Up to 25%.

Formulas used in - Sunscreens, nappy rash creams, colour cosmetics.

Formulation notes - Zinc oxide needs to be dispersed in the oil phase of formulation it is best used in W/O or W/SI emulsions. Pre- dispersed versions of zinc oxide that disperse more readily are available on the market. Proper dispersion of zinc oxide particularly in sunscreens is paramount.

Odour - Odourless.

Form - Powder, can come in a pre-dispersed form for better dispersion.

Heat sensitivity - Not heat sensitive.

Solubility - Insoluble in water and oil but can be dispersed in oil.

Natural / synthetic status - Zinc oxide is accepted as a natural ingredient however technically it is synthetic due to the way it is processed.

Contraindications - Allergic reactions are rare with zinc oxide however can happen. As with any new ingredient, it’s advisable to patch-test before full application, especially on sensitive skin.