Homosalate, Explained: What the EU's 0.5 and 7.34 Percent Opinions, the UK's 10 Percent Opinion and the FDA's Proposed Order Say
Homosalate is a UV filter on many sunscreen labels, and three regulators have read the same evidence differently. Europe's committee first said 10 percent was not safe, then accepted a higher figure for faces. A UK group later disagreed, and the US FDA is still waiting for data.
What homosalate does in a sunscreen
Homosalate is an organic (chemical) broad-band UV filter. The UK advisory group says that at up to 10 percent it can contribute to sun protection factors of 10 to 50.
The EU's 2021 opinion: 0.5 percent
In June 2021 the EU's Scientific Committee on Consumer Safety (SCCS) concluded that homosalate could not be considered safe at up to 10 percent, but was safe up to 0.5 percent in the final product when used in sunscreen, hand cream and face cream. A 2007 opinion had found no risk at 10 percent but did not assess sprays.
Where the 0.5 percent comes from
The starting point was a rat study with effects at 60 mg/kg a day, adjusted to 10 mg/kg a day. It assumed 5.3 percent of the dose crosses skin, from an in vitro study. At 10 percent that gives an exposure of 1.59 mg/kg a day, a margin of safety of 6.3. The target margin is at least 100, meaning about 0.1 mg/kg a day, or 0.5 percent.
The December 2021 advice: 7.34 percent on the face
Industry recalculated for face products only, using 1.54 g of cream a day. At 7.34 percent the exposure was 0.0998 mg/kg a day, a margin of 100.2. A face pump spray, counting skin plus inhalation, came to 100.1. The SCCS judged both safe at up to 7.34 percent.
The hormone question
The SCCS called the endocrine evidence "inconclusive, and at best equivocal". Cell tests showed anti-androgenic and estrogenic signals, but the UK group says those concentrations are hard to apply to cosmetic use, and a rat test was negative. That is uncertainty, not a demonstrated effect in people.
The UK view and the US position
In March 2025 the UK's SAG-CS accepted 120 mg/kg a day as the starting point and, using modelling, cut the required margin from 100 to 25. It concluded 10 percent is safe in sunscreen. The FDA monograph lists homosalate up to 15 percent, but its 2021 proposed order says more data are needed. That is not a finding of harm; our octocrylene guide covers the order. Limits differ by market, so check current rules.
Reading the label
Look for "homosalate" in the ingredient list, often beside filters such as in our avobenzone guide. For aerosols, see the spray sunscreen guide.
Short version
Regulators agree on the arithmetic but differ on which rat dose to trust, and sunscreen filters also protect against UV damage. Try new sunscreen with our patch-test method. This article is educational, not medical advice: patch-test new products first, and ask a dermatologist about acne, rosacea or any persistent skin problem.
All content is fact-checked under our editorial standards.