What Is It?
Zinc Oxide (ZnO) is powdered, oxidized zinc derived from the naturally occurring mineral, zincite, and routinely used in a wide range of consumer products.
Zinc Oxide is well recognized as a key sunscreen ingredient that is effective in providing protection from UV light. It plays an important role in safeguarding public health. It is also widely used as an additive in rubbers, plastics, ceramics, lubricants, paints, ointments, adhesives, sealants, pigments, foods, first-aid tapes and other materials and products.
Why is it used in cosmetics and personal care products?
Zinc oxide is used in a wide range of cosmetics and personal care products including makeup, baby lotions, bath soaps and foot powders. It is used as a bulking agent, a colorant, a skin protectant in over-the-counter (OTC) drug products and as a sunscreen.
When used in sunscreen products, ZnO acts as a physical block to the sun’s ultraviolet (UV) radiation, helping to reduce or prevent sunburn and premature aging of the skin. Preventing sunburn is an important factor in reducing skin cancer risk. Zinc oxide is the broadest spectrum UVA and UVB reflector approved for use as a sunscreen by the FDA and is allowed in concentrations up to 25%. When used as an ingredient in sunscreen, zinc oxide screens both UVA (320–400 nm) and UVB (280–320 nm) rays of ultraviolet light.
ZnO is widely used to treat a variety of skin conditions in products such as calamine cream and antiseptic ointments, and as a skin protectant ingredient in products including in concentrations up to 40% in diaper rash ointments.
Zinc compounds were likely used by early humans as a paint or medicinal ointment, but their composition is uncertain. The use of pushpanjan, probably zinc oxide, as a salve for eyes and open wounds, is mentioned in the Indian medical text the Charaka Samhita, thought to date from 500 BC or before. Zinc oxide ointment is also mentioned by the Greek physician Dioscorides (1st century AD.) Avicenna mentions zinc oxide in The Canon of Medicine (1025 AD), which identifies it as a preferred treatment for a variety of skin conditions, including skin cancer, though it is no longer used for treating skin cancer.
The Food and Drug Administration (FDA) lists zinc oxide as generally recognized as safe (GRAS) as a nutrient. It is also approved as an indirect food additive for use as a colorant of some polymers in contact with food. Zinc oxide is approved by FDA for use in color cosmetic products, including those applied to the lips and eye area. Zinc oxide is also an approved colorant for drugs.
FDA only approves colors after extensive review of all safety data and publication of the basis for its approval in the Federal Register. When used as a colorant in cosmetics or other FDA-regulated products, zinc oxide must comply with the identity, specifications, uses, restrictions, and labeling requirements stated in the regulations [21 CFR 73].
FDA has approved the use of zinc oxide for use in OTC skin protectants and anorectal skin protectant drug products at concentrations up to 25 percent, and in sunscreen drug products at concentrations up to 25 percent.
Overall, FDA has conducted extensive reviews of the safety of zinc oxide for use as a color additive in drugs and cosmetics and as a sunscreen and skin protectant active ingredient. The results of these reviews are publically available information.
European Union (EU)
The Cosmetics Directive of the European Union approved the use of zinc oxide as a color (see Annex IV Part 1); when used in cosmetic products in the European Union (EU), this ingredient must be called CI 77947. In its September 18, 2012 opinion (revised September 23, 2014), the EU’s Scientific Committee on Consumer Safety (SCCS) concluded the use of zinc oxide is safe when used as colorant, in its uncoated, non-nano form, in cosmetics for dermal application. In light of subsequent SCCS concerns of lung inflammation induced by zinc oxide particles after inhalation, however, the European Commission amended Annex IV of the Cosmetics Regulation in August 2017 to stipulate the use of zinc oxide as a colorant, in its uncoated non-nano form, in cosmetic products should be restricted to those applications that will not lead to exposure of the end-user’s lungs.
Zinc oxide is also allowed as a UV filter in the EU. The SCCS has thoroughly reviewed the safety of nano-sized zinc oxide used in sunscreens and concluded at concentrations up to 25% used on the skin, it does not pose a risk of adverse effects. In 2016, the European Commission published a new regulation amending Annex VI of the EU Cosmetics Regulation to include a new entry for zinc oxide in the nanoparticle form as a permitted UV filter in ready-to-use cosmetic products. The new Annex VI entry #30a for zinc oxide (nano) is in addition to the existing entry #30 for zinc oxide, and authorizes the use of zinc oxide in the nano form as an approved nanomaterial ingredient. Use of both nano and non-nano forms are restricted to applications that will not lead to exposure of the end-user’s lungs. Zinc oxide is used mainly in sunscreens but may also appear in other cosmetic products intended for dermal application. The maximum permitted concentration of both nano and non-nano zinc oxide is 25%, whether used individually or in combination.