Diethylamino Hydroxybenzoyl Hexyl Benzoate
Also known as DHHB, Uvinul A Plus, Benzoic acid, 2-[4-(diethylamino)-2-hydroxybenzoyl]-, hexyl ester
“EU CosIng says: restricted.”
DHHB (CAS 302776-68-7) is an organic UVA filter approved in the EU at up to 10% in cosmetic products (Annex VI entry 28, added by Commission Regulation (EU) 2016/1143). It is not approved by the US FDA as an OTC sunscreen active ingredient and is absent from the CIR Quick Reference Table, reflecting its status as an EU-only approved UV filter. The SCCS issued scientific advice in 2025 (SCCS/1678/25) specifically on the manufacturing impurity di-n-hexyl phthalate (DnHexP, CAS 84-75-3), concluding that DnHexP must not exceed 0.026% (260 ppm) in the DHHB substance at the 10% use level to maintain a margin of safety of 100. DHHB's primary safety was established by SCCP/1166/08 (2008). Environmental concerns have been raised regarding chlorinated disinfection byproducts formed when DHHB enters swimming pool water (PMID 37068670).
Approved UVA filter (primarily UVA II: 310–400 nm) in the EU at up to 10% in both leave-on and rinse-off products
High molar extinction coefficient in the UVA region; provides strong UVA absorption
Photostable UV filter — maintains UV-absorbing capacity under UV irradiation without significant degradation
Good cosmetic elegance and compatibility with other UV filters; the SCCP (2008) concluded DHHB is safe for use in cosmetics at the 10% maximum concentration
- · Not FDA-approved as a US OTC sunscreen active ingredient; absent from 21 CFR Part 352 and from the CIR Quick Reference Table — US products cannot legally use DHHB as a sunscreen active
- · Environmental/chlorination concern: DHHB undergoes transformation in chlorinated swimming pool water, forming disinfection byproducts with increased toxicity compared to the parent compound
- · No independent CIR safety assessment; safety basis is EU SCCS opinions only (SCCP/1166/08 for DHHB itself; SCCS/1678/25 for DnHexP impurity limit)
Manufacturing impurity DnHexP (di-n-hexyl phthalate, CAS 84-75-3, a CMR substance prohibited in cosmetics under Annex II entry 1559): SCCS/1678/25 (2025) established safe limit at 260 ppm (0.026%) in DHHB substance at 10% use level
EU Regulation 1223/2009 Annex VI — UV filters (consolidated), entry 28: Diethylamino Hydroxy Benzoyl Hexyl Benzoate (CAS 302776-68-7), ma…
SCCS/1678/25 — Scientific Advice on the safety of Diethylamino Hydroxybenzoyl Hexyl Benzoate (DHHB) S83 (CAS/EC No. 302776-68-7/443-860-6…
“DHHB has been authorised for use in cosmetic products as a UV-filter (entry 28 of Annex VI to the Cosmetics Regulation (EC) No. 1223/2009)”— SCCS/1678/25, p. 6, section 2 Mandate from the European Commission — Background