Titanium Dioxide

Overview

Titanium dioxide is one of two mineral UV filters widely accepted in cosmetic sunscreens worldwide (the other being zinc oxide). It is a naturally occurring mineral — typically sourced from ilmenite ore — that is refined into a fine white powder. In sunscreen, it sits on the skin surface and reflects, scatters, and absorbs UV radiation before it reaches living cells.

It is also one of the most common white pigments in cosmetics, used to opacify lotions (turning translucent emulsions white) and as a base pigment in mineral makeup, foundations, and color cosmetics. The CI 77891 color index number reflects this dual identity — it is both a functional UV filter and a colorant.

Two things matter when sourcing titanium dioxide: cosmetic-grade vs. food-grade and nano vs. non-nano. Always use cosmetic-grade — food-grade variants may contain additives not intended for skin application. The nano distinction (particles under 100 nm) affects both UV performance and labeling requirements. Nano grades provide better UV protection with less white cast, but many regulatory jurisdictions require “nano” to appear in the INCI list.

What it does in a formula

As a UV filter, titanium dioxide provides strong UVB protection and moderate UVA-II protection. It is weaker in the UVA-I range (340-400 nm), which is why it is frequently combined with zinc oxide for genuinely broad-spectrum coverage. At 15-25%, it can contribute significantly to SPF — though actual SPF depends on particle size, coating, dispersion quality, and film thickness on skin.

As an opacifier, 0.5-5% will turn a translucent lotion or cream into an opaque white product. This is purely aesthetic — it does not add meaningful UV protection at those low percentages.

In mineral makeup, it serves as the white base that is blended with iron oxides and other pigments to create foundation shades.

How to use

Coated grades (treated with dimethicone, alumina, stearic acid, or similar): add to the oil phase. The coating makes the particles hydrophobic, so they disperse into oils and oil-in-water emulsions. This is the most common format for DIY sunscreens.

Uncoated grades: can be dispersed in the water phase, but are harder to work with and more prone to clumping. Coated grades are recommended for most home formulators.

Sunscreens: 5-25% depending on target SPF. Pre-disperse in a small amount of oil using a spatula or electric mixer before adding to the main batch. Clumps of undispersed titanium dioxide reduce UV protection and look terrible.

Opacifier in lotions: 0.5-2%. Sift into the oil phase and mix thoroughly.

Mineral makeup: 10-30% depending on desired coverage, blended with iron oxides, zinc oxide, and fillers like mica or silk powder.

Do not rely on titanium dioxide alone for full broad-spectrum protection — pair it with zinc oxide for adequate UVA-I coverage.

Best for / Worst for

Best for: mineral sunscreens, tinted moisturizers with SPF, mineral foundation and powder makeup, opacifying white lotions, baby sunscreens (gentle, non-chemical filter).

Worst for: clear or translucent products (it is opaque white), deep skin tones at high percentages (significant white cast unless using nano or tinted formulations), anhydrous products without proper dispersion tools.

Common pitfalls

Poor dispersion. The number-one failure point. If you dump titanium dioxide powder into a lotion and stir, you get clumps — not protection. Use a high-shear mixer, or at minimum pre-disperse in a small amount of oil with an immersion blender.

Using food-grade TiO2. Food-grade titanium dioxide is processed differently and may contain particle sizes or coatings inappropriate for skin. Cosmetic or USP-grade only.

Claiming SPF without testing. No amount of math or published data replaces an actual SPF test. If you sell a sunscreen, it must be tested. Period. For personal use, understand that your kitchen-made sunscreen has an unknown SPF.

Ignoring nano labeling. If your titanium dioxide is nano-grade (particles < 100 nm), regulatory frameworks in the EU, Australia, and elsewhere require you to list it as “Titanium Dioxide [nano]” in the INCI. Know what you are buying.

Forgetting the white cast. At 15%+ in a sunscreen, untinted titanium dioxide leaves a visible white film on all but the lightest skin tones. Add iron oxides for a universal tint, or use nano-grade to reduce the cast.

Substitutes

• Zinc oxide — the other mineral UV filter. Better UVA-I coverage, slightly worse UVB. Often used alongside titanium dioxide for full-spectrum protection.
• Iron oxides — provide visible-light protection and tint. Not a UV filter replacement, but complementary in tinted sunscreens.
• Boron nitride — silky white powder used in makeup for soft-focus effect. No UV protection, purely cosmetic.