Zinc Oxide, 100 g

Zinc oxide (Zinc Oxide) fulfils three roles in a formulation at once: it acts as a physical UV filter, a white pigment and an active ingredient for irritated and problem skin. It is one of the basic raw materials for zinc creams and ointments, baby care products, mineral make-up, lip balms and soaps. It dissolves in neither water nor oil and is incorporated into the recipe as a dispersed powder, which requires different handling from water-soluble active ingredients.

The raw material is of cosmetic and pharmaceutical grade with a purity of at least 99.9%. The particles have an average size of up to 0.8 µm and the product is not a nanomaterial. Nanomaterials are not used, added or formed during production, which matters to manufacturers who want to avoid nanoparticles in cosmetics. Zinc oxide is of mineral, European origin, contains no ingredients of animal origin and has not been tested on animals for cosmetic purposes.

Key benefits

• Physical UV filter – reflects and scatters UV radiation on the surface of the skin. The resulting protection of the finished product depends on the usage rate, the evenness of dispersion and the overall composition.
• Opaque white pigment – in mineral powders and make-up it forms part of the pigment base and provides coverage. In soaps it whitens the base.
• Active ingredient for irritated skin – a traditional component of zinc ointments and creams for reddened and acne-prone skin and of protective nappy area creams.
• Neutral pH – the raw material has a pH of 6.8–7.4, so it does not push the pH of the formulation to extremes and is suitable for products for sensitive and baby skin.

Use in formulations

The powder does not dissolve in any phase, it only disperses. The best results come from premixing it into part of the oil phase or into a single oil to form a smooth paste without lumps, which is then incorporated into the emulsion. In emulsions it is usually added after emulsification, into the partially cooled mixture at a temperature below 80 °C. The recommended usage rate is 1–25%, depending on whether the raw material is to act as an active ingredient, a pigment or a UV filter.

In anhydrous products such as ointments, balms and solid sticks, the powder is stirred into the melted oil phase. The mixture is stirred continuously as it cools so that the pigment does not settle at the bottom. In thin water-based systems it settles over time, so it belongs in creams, ointments and pastes, not in toners or sprays.

Zinc oxide reacts with acids and alkalis. Recipes outside the pH range of 6.8–7.4 and combinations with strongly acidic ingredients, for example AHAs, are therefore not suitable. If you plan such a combination, check the stability in the finished formulation.

Suitable for products such as

• Zinc creams and ointments – for irritated and reddened skin on the body and face, where a covering effect is desired.
• Baby care products – protective creams and pastes for the nappy area.
• Products for acne-prone skin – topical creams and pastes for oily and problem skin.
• Decorative cosmetics – mineral powders, make-up and concealers, where it serves as an opaque white pigment.
• Lip balms – the raw material is also intended for the lip area, and in balms it provides coverage and a lighter shade.
• Soaps – a white pigment for whitening the soap base.

Good to know

Zinc oxide is a leave-on raw material intended for products that remain on the skin. Every emulsion or balm turns white and acquires an opaque appearance once zinc oxide is added. At higher usage rates it leaves a white film on the skin, which must be taken into account when designing the recipe, especially for darker skin tones. The protective effect depends on the even dispersion of the particles, so lumps and sediment in the product are a functional problem, not just an aesthetic one.

The powder is very fine and creates dust when weighed. Add it slowly and without stirring up dust. The product is subject to classification under the CLP Regulation and bears the GHS09 pictogram (hazardous to the environment), so residues and rinsing water must not be poured into wastewater. You will find details on classification and safe handling in the safety data sheet.

Frequently asked questions