Glossary

UV Filter

Written by Reviewed by the SYNC editorial team Published Last reviewed Editorial standards

UV Filter — an ingredient added to sunscreen that absorbs or reflects ultraviolet radiation to reduce how much reaches the skin. UV filters are the functional actives responsible for a product's SPF and broad-spectrum protection, and they are broadly grouped into organic and inorganic types.

Key points

  • UV filters protect skin by absorbing, scattering, or reflecting ultraviolet radiation before it penetrates.
  • They are divided into organic (carbon-based) filters and inorganic (mineral) filters like zinc oxide and titanium dioxide.
  • Broad-spectrum protection requires filters that cover both UVA and UVB wavelengths.
  • Approved UV filters and their permitted concentrations vary by country and regulatory region.

Frequently asked

What is the difference between UVA and UVB protection?

UVB rays mainly cause sunburn and are the primary driver of SPF ratings, while UVA rays penetrate deeper and contribute to aging; broad-spectrum filters address both.

Are UV filters the same everywhere in the world?

No, the list of approved UV filters and their allowed concentrations differs between regulatory regions such as the US, EU, and Asia.

Related topics

This is a foundational entry in the SYNC Skin Encyclopedia and is expanded over time. Educational information only — not medical advice.

Encyclopedia

Further reading

This entry was written and checked against the sources below. They are published by clinical and scientific bodies, they are listed most readable first, and each one opens in a new tab. They are background for the whole entry rather than footnotes to individual sentences.

  1. Introduction to Sunscreens and Their UV Filters - Review of Fate, Exposure, and Effects of Sunscreens in Aquatic Environments and Implications for Sunscreen… StatPearls (NCBI Bookshelf) Reference text ncbi.nlm.nih.gov
  2. Questions and Answers: FDA posts deemed final order and proposed order for over-the-counter sunscreen U.S. FDA Regulatory and safety fda.gov
  3. Sunscreen: How to Help Protect Your Skin from the Sun U.S. FDA Regulatory and safety fda.gov
  4. Ultraviolet Filters: Dissecting Current Facts and Myths PubMed Central Peer-reviewed, open access pmc.ncbi.nlm.nih.gov
  5. Ultraviolet radiation and human health DermNet NZ Clinical guidance dermnetnz.org
  6. Ultraviolet (UV) Radiation U.S. FDA Regulatory and safety fda.gov

SYNC does not publish medical advice. Nothing here replaces a consultation with a doctor or a pharmacist about your own skin.