What it is
Diethylamino hydroxybenzoyl hexyl benzoate is an oil-soluble organic sunscreen agent designed specifically to absorb long-wave UVA radiation, with an absorption maximum around 354 nm. It works by absorbing this high-energy light and releasing it as harmless heat. It is noted for excellent photostability and good compatibility with other UV absorbers and cosmetic ingredients, which makes it a popular partner for stabilizing less stable filters in a sunscreen.
Spectrum coverage
UVA1 · UVA2
Regional approval · max %
Safety & warnings
DHHB is generally regarded as a well-tolerated modern UVA filter and is not associated with the photostability problems of some older filters. One manufacturing-related consideration is potential trace contamination with di-n-hexyl phthalate; European safety authorities set a maximum acceptable level for this impurity, and manufacturers target levels far below it, so consumer-grade material is controlled for this.
Origin & sourcing
It is a fully synthetic molecule. Industrially it is produced in two steps: a reaction between 3-hydroxy-N,N-diethylaniline and phthalic anhydride, followed by esterification with 1-hexanol to give the final oil-soluble benzoate ester.
History
The filter is marketed as Uvinul A Plus by BASF and as Parsol DHHB by DSM. It was approved for use in sunscreens in the European Union in 2005, and is also approved in markets including Japan, Taiwan, Mexico, and parts of South America; in the United States it is permitted as a product-protection additive rather than as a labeled sunscreen active.
Questions everyone asks
What does Uvinul A Plus protect against?
It is a UVA filter, absorbing long-wave UVA light with peak absorption near 354 nm to complement UVB filters in a sunscreen.
Is DHHB a stable sunscreen ingredient?
Yes. It is noted for excellent photostability and compatibility with other UV filters, and is often used to help stabilize the overall formula.
Why isn't it in American sunscreens?
In the United States it is permitted only for product protection, not as an approved labeled sunscreen active, so US sunscreens cannot count it toward SPF.