Zinc Oxide
Zinc Oxide (CAS 1314-13-2) is a physical (inorganic) sunscreen agent that works by absorbing UV radiation rather than reflecting or scattering it. It provides broad-spectrum protection covering UVB, UVA II, and UVA I almost uniformly, making it the widest-range sunscreen available. It is also used as a bulking agent, cosmetic colorant, and skin protectant. It is subject to cosmetic restrictions prohibiting use in applications that may lead to inhalation exposure.
Zinc Oxide offers the broadest UV spectrum protection of any sunscreen ingredient, covering UVB, UVA II, and UVA I. It is highly stable and non-irritating, and also functions as a skin protectant and anti-irritant, with established use in treating skin irritations such as diaper rash.
Not to be used in applications that may lead to inhalation of the ingredient by the end user (EU Cosmetic Restrictions IV/144). Nanoparticle forms are subject to ongoing safety scrutiny, though current research indicates sunscreen nanoparticles are not absorbed beyond the uppermost (dead) layer of skin. Leaves a noticeable whitish tint on skin, which is a cosmetic drawback.
