Effective sun protection depends on choosing the right organic UV filter — and understanding its photostability, regulatory status, and formulation behaviour. Most commercial sunscreens still rely on a narrow set of filters, each with specific limitations that formulators must engineer around.
This series covers the two most significant organic UVA filters available to cosmetic manufacturers — Avobenzone (Butyl Methoxydibenzoylmethane) and DHHB (Diethylamino Hydroxybenzoyl Hexyl Benzoate) — along with the regulatory frameworks that govern their use in finished products.
UVB 280–320 nm
UVA-II 320–340 nm
UVA-I 340–400 nm
Organic UV Filter Technical Guides
UVA-I Filter
Avobenzone Technical Guide
The most widely used UVA-I filter — and the most photolabile. This guide covers the keto-enol tautomerism that drives photodegradation, proven stabilisation strategies (Octocrylene, DHHB, Tinosorb S), and concentration limits across EU, US, and ASEAN frameworks.
Read full guide →
Broad UVA Filter
DHHB Formulation Guide
A photostable alternative that doubles as an Avobenzone stabiliser. This guide details DHHB’s triplet-state quenching mechanism, solubility profile across common emollients, EU-approved concentration limits, and its role in next-generation broad-spectrum systems.
Read full guide →EU vs US Sunscreen Regulation
The same SPF number can mean different things depending on where the product is sold. EU treats sunscreen as a cosmetic product; the US treats it as an OTC drug. This guide breaks down the testing methodology, labelling requirements, and approved filter lists that separate the two systems.
Read the regulation comparison →| Parameter | EU | US |
|---|---|---|
| Product class | Cosmetic | OTC Drug |
| SPF test method | ISO 24444 | FDA monograph |
| UVA requirement | ⅓ of SPF (mandatory) | Broad Spectrum test |
| DHHB status | Approved (10%) | Not approved |
| Max SPF label | 50+ | 80 (proposed 60+) |
Related Formulation & Science
UV protection intersects with antioxidant defence and complete formulation design.
Hybrid SPF30 Sunscreen Formula
Avobenzone + DHHB + mineral filters — a complete worked example
Ferulic Acid Technical Guide
UV absorption (λmax 322 nm) + antioxidant network — the photo-protection bridge
UV Filter Ingredients from Onerchem
Need UV Filter Samples?
Request Avobenzone or DHHB samples with full COA and MSDS documentation.
Request SamplesFrequently Asked Questions
Both are organic UVA filters with peak absorption near 354–357 nm, but they differ in photostability. Avobenzone undergoes keto-enol tautomerism under UV exposure and loses efficacy unless stabilised. DHHB is inherently photostable and can act as a triplet-state quencher for Avobenzone — making the two complementary in broad-spectrum systems. See the Avobenzone guide and DHHB guide for detailed comparisons.
No. DHHB (Uvinul A Plus) is approved in the EU at up to 10% concentration and in many ASEAN markets, but it is not included in the FDA’s monograph of approved sunscreen actives. Products containing DHHB cannot be sold as sunscreens in the US market. Our EU vs US regulation guide covers the full list of approved filters in each jurisdiction.
The three proven stabilisation approaches are: (1) adding a triplet-state quencher like DHHB or Tinosorb S, (2) using Octocrylene as a photostabiliser at 2–5%, and (3) encapsulation in solid lipid nanoparticles. Combining at least two methods is recommended for SPF 30+ products. The Avobenzone Technical Guide covers each approach with concentration ranges.
In the EU, a sunscreen must provide UVA protection of at least one-third of the labelled SPF value (measured by persistent pigment darkening). In the US, a product passes the “Broad Spectrum” test if its critical wavelength is ≥370 nm. The two methods test different things — read the full comparison to understand the practical implications for formulation.
No. Ferulic Acid absorbs UV radiation (λmax ~322 nm) and provides antioxidant photo-protection, but it is not classified as a UV filter in any regulatory framework and cannot be used to claim SPF. It works best as a booster ingredient alongside approved UV filters — reducing oxidative stress that filters alone cannot prevent. See the Ferulic Acid Technical Guide.