Zinc Oxide: The Original Broad-Spectrum Filter
The mineral workhorse, fully explained.
Avobenzone can lose significant UV-absorbing power within an hour unless paired with stabilizers.
Tinosorb M works as a hybrid filter, both absorbing and physically scattering UV light.
Frequently asked questions
Which sunscreen filters are approved in the US vs the EU?
The EU has approved 34 UV filters for sunscreens; the US allows about 16 (now 17 with bemotrizinol's 2026 approval). Filters widely used in Europe and Asia — such as bisoctrizole, drometrizole trisiloxane and Mexoryl 400 — remain under FDA review, which is why US options have lagged.
What does broad-spectrum protection actually mean?
'Broad-spectrum' means a sunscreen protects against both UVA and UVB. In the US a product must pass an FDA critical-wavelength test to make the claim. Because SPF only measures UVB protection, broad-spectrum labeling is how you know you're also covered against deeper, aging UVA rays.
Why are some UV filters more photostable?
A photostable filter keeps absorbing UV without breaking down in sunlight. Older filters like avobenzone can lose protection within an hour unless paired with stabilizers such as octocrylene. Next-generation filters are engineered to stay chemically stable, so protection lasts longer — though reapplication is still advised.
r/AsianBeauty: 'Why are European/Korean filters considered more elegant?'
Sources & citations
- Holland & Knight, 'FDA Proposes First New Sunscreen Ingredient in Decades' (Dec 2025)
- hklaw.com ↗