Zinc Oxide and Titanium Dioxide (Mineral Sunscreen Filters)

What are zinc oxide and titanium dioxide and what do they do?

Zinc oxide and titanium dioxide are inorganic UV filters. Contrary to the common description of them as reflectors, they protect mainly by absorbing ultraviolet radiation, with a smaller contribution from scattering and reflection. Zinc oxide covers a broad range across UVB and UVA, including long UVA; titanium dioxide is strongest in UVB and short UVA. Larger particles leave a visible white cast, so many products use micronised or nano-sized particles, which are more cosmetically acceptable. Tinted mineral sunscreens containing iron oxides also filter visible light, which is relevant for melasma and pigmentation-prone skin. They are generally well tolerated by sensitive skin. [1]

“In Singapore, sunscreens are regulated as cosmetic products, unlike the United States where they are over-the-counter medicines.”

Dr Sin YongOn sunscreen regulation in Singapore

What does the evidence show?

Reviews of inorganic UV filters describe well-established photoprotection and a favourable irritation profile. Safety reviews of nano-sized zinc oxide and titanium dioxide conclude that the particles remain largely on the outer skin layer of intact skin, with minimal penetration. Studies on tinted sunscreens support added visible-light protection for melasma. Real-world protection depends heavily on applying enough product and reapplying, which matters more than the choice between mineral and chemical filters.

Who should avoid zinc oxide and titanium dioxide?

Mineral filters suit most people, including sensitive skin and children over six months. The white cast can be noticeable on darker skin tones, so tinted versions may be preferable. Some formulations feel heavy or may aggravate acne-prone skin. Spray or powder forms containing these particles should not be inhaled.

Are zinc oxide and titanium dioxide available in Singapore?

In Singapore, sunscreens are regulated as cosmetic products, unlike the United States where they are over-the-counter medicines. Zinc oxide and titanium dioxide are on the list of permitted UV filters under the ASEAN cosmetic rules that Singapore follows, with maximum concentrations. Check the label for broad-spectrum protection and SPF.

If a dark patch, breakout or irritation is not responding to what you are using, the next step is a diagnosis rather than another product. See the Skin A–Z library for related ingredients.