Titanium Dioxide in Sunscreen: Lab SPF, Safety and Which Products Use It

Particle Size and White Cast

The same material is used as a white pigment and as a sunscreen filter. The FDA's 2019 proposed rule describes pigment-grade titanium dioxide with particles of typically 200 to 300 nm, and grades of 15 to 50 nm made "to reduce its white/opaque appearance". Making the particles smaller trades white cast for some UVA coverage: Smijs and Pavel’s 2011 review notes that titanium dioxide's whiteness gives way to transparency at 10 to 20 nm, and that "the particle size reduction thus decreases UVA absorption ability and shifts it to the UVB area". The same review finds zinc oxide's whitening effect lower than titanium dioxide's.

Scientific Research on UV Protection

Is Titanium Dioxide in Sunscreen Safe?

For use on skin, the FDA has proposed it as safe and effective and the EU permits it, both at up to 25%; the EU's restriction concerns inhalation. In its 2019 proposed rule, the FDA proposed that titanium dioxide, "regardless of particle size", is GRASE (generally recognized as safe and effective) in sunscreens at up to 25%, citing studies showing that it "does not penetrate into the skin or enter into systemic circulation to any meaningful extent". With zinc oxide, it is one of only two of the 16 long-established US sunscreen actives proposed as GRASE. The proposal was carried into proposed order OTC000008 in 2021 and has not been finalized for titanium dioxide; the FDA has finalized only that order's PABA and trolamine salicylate proposals (as OTC000008-1) and says it will address the rest "in a future order or orders". Meanwhile titanium dioxide stays listed "up to 25 percent" in the current monograph M020. The same FDA Q&A page notes that asking for more data on other filters "does not represent a conclusion" that they are unsafe.

The FDA also expects few skin reactions. Because so little titanium dioxide reaches living skin cells, its 2019 proposal reasoned, this "also prevents dermal irritation, sensitization reactions, and photosafety issues for this ingredient", and it did not ask for new irritation or allergy studies. For the same reason it judged the safety margin large and considered pediatric studies "unnecessary for this ingredient". That is a regulator's reasoning about the ingredient, not a test of any particular product: monograph M020 still requires every sunscreen label to say "children under 6 months of age: Ask a doctor" and to apply it "15 minutes before sun exposure".

In the EU, Annex VI of the Cosmetics Regulation lists titanium dioxide (entry 27) and titanium dioxide (nano) (entry 27a) as UV filters at up to 25%, and the two used together may not exceed that limit. The nano form is "not to be used in applications that may lead to exposure of the end-user’s lungs by inhalation", and only coated, mainly rutile nanoparticles with a median size of at least 30 nm and no more than 10% of the photocatalytic activity of uncoated material are allowed. Those conditions closely follow the 2013 opinion of the EU's Scientific Committee on Consumer Safety, which concluded that such nanoparticles at up to 25% "can be considered to not pose any risk of adverse effects in humans after application on healthy, intact or sunburnt skin", but that this "does not apply to applications that might lead to inhalation exposure to TiO2 nanoparticles (such as powders or sprayable products)".

The EU's titanium dioxide ban applies to food. Regulation (EU) 2022/63 removed the food additive E171 after the European Food Safety Authority concluded that it "can no longer be considered safe when used as a food additive". That regulation amends the food additives rules; the cosmetics annex, in its consolidated text of 18 May 2026, still lists titanium dioxide as a UV filter at up to 25%.

Sources: FDA, Sunscreen Drug Products for Over-the-Counter Human Use, proposed rule, 84 FR 6204 (26 February 2019), section VIII.A.2; FDA, Questions and Answers: FDA's regulatory actions on over-the-counter sunscreen (content current as of 10 September 2026); FDA, OTC Monograph M020, Sunscreen Drug Products for Over-the-Counter Human Use (effective 9 August 2026); Regulation (EC) No 1223/2009, Annex VI entries 27 and 27a, consolidated text of 18 May 2026; SCCS/1516/13, Opinion on Titanium Dioxide (nano form), adopted 22 July 2013, revised 22 April 2014; Commission Regulation (EU) 2022/63 of 14 January 2022.

Coatings and Photocatalytic Activity

Sunscreen-grade particles are often coated; the FDA lists "silicones, metal oxides, or organic acids", applied partly to improve the look of the finished formula. Coatings also matter because titanium dioxide is photocatalytic: under UV light its surface can generate reactive oxygen species, and the anatase crystal form is more active than rutile. Coatings reduce this activity but do not eliminate it. Smijs and Pavel concluded that photocatalytic effects, "the highest for anatase TiO2, cannot be completely prevented by coating of the particles, but silica-based coatings are most effective".

A 2026 cell study by Katsanou and colleagues measured the effect. In a three-hour dye-degradation test under UVA light, uncoated anatase-rich nanoparticles broke down 64% of the dye, silica-coated ones 59% and alumina-silica-coated ones 24% (70%, 55% and 22% under UVB); in skin cells under UVA, the alumina-silica coating gave the greatest protection, "substantially reducing but not eliminating cytotoxicity". The authors tested bare particles in cell culture, not finished sunscreens on skin, and their particles were anatase-rich, the form the EU limits to 5% in nano titanium dioxide for cosmetics.

References: FDA, 84 FR 6204 (2019), section VIII.A.2; Smijs and Pavel 2011 (above); Katsanou ME, Ficht PK, Wegewitz L, et al. Impact of Surface Coatings on the Photocatalytic Activity and Cytotoxicity of Titanium Dioxide Nanoparticles in Human Keratinocytes: Implications for Sunscreen Safety. ACS Omega. 2026;11(24):35180-35190. doi:10.1021/acsomega.5c13018.

Comparison and Recommendations

In the 2008 comparison, the best titanium dioxide grade reached a higher in vitro SPF than any zinc oxide grade, while zinc oxide is the more efficient UVA absorber, so the two are often combined: 13 of the 14 titanium dioxide labels on our mineral sunscreen list also contain zinc oxide. Tinted formulas may add iron oxides as well; our guide checks which tinted sunscreens list iron oxides on the label.

The titanium dioxide percentage on a label is not a guide to protection. The 14 labels on our list carry 2% to 11.01% titanium dioxide, far below the 25% used in the lab comparison, and a finished product's SPF is measured on the whole formula. Compare the labeled SPF and broad-spectrum claim instead.