Sunscreen filters
Octisalate
Also listed as ethylhexyl salicylate, octyl salicylate, EHS
A weak UVB filter used mainly to top up SPF and help dissolve other filters. Low allergy risk; absorbed, like most organic filters.
What it is
Octisalate is a salicylate that absorbs UVB (peak around 307 nm). It is weak on its own, so it is almost always one of several filters, adding a little SPF and acting as a solvent that keeps crystalline filters such as avobenzone dissolved.
In perfumes it is added in small amounts to protect the scent and colour from light.
How strong is the evidence?
Moderate evidenceIts UVB absorption is well characterised, but its contribution to a product's protection is modest. The FDA trial found blood levels around 5 ng/mL, above the screening threshold. There is no human evidence of harm; FDA lists it as needing more safety data.
What it's used for, checked
Adds UVB protection
Holds upA supporting filter; the product's SPF depends on the whole combination.
Protects from UVA
FalseIt barely absorbs UVA; broad-spectrum claims rely on other filters.
Works well with
- avobenzone
- homosalate
Who should be careful
- Allergy is rare.
- No special restrictions for children beyond general sunscreen advice (shade first under 6 months).
The studies
Every citation is checked against its PubMed record.
- Effect of Sunscreen Application on Plasma Concentration of Sunscreen Active Ingredients: A Randomized Clinical Trial. Matta MK, Florian J, Zusterzeel R, et al. · JAMA · 2020 · RCT (pharmacokinetic)
48 healthy adults applied one of four sunscreens to 75% of the body, up to 4 times a day for 4 days. Avobenzone, oxybenzone, octocrylene, homosalate, octisalate and octinoxate all exceeded the FDA's 0.5 ng/mL screening threshold after a single application; oxybenzone reached about 258 ng/mL from lotion. The authors state this does not mean people should stop using sunscreen.