Ensulizole vs Padimate O: which is worse?

What is Ensulizole?

Ensulizole (INCI: Phenylbenzimidazole Sulfonic Acid) is a water-soluble UVB-absorbing chemical sunscreen active. Because it is water-based, it provides a lighter, less oily feel compared to oil-soluble UV filters.

What is Padimate O?

Padimate O (octyl dimethyl PABA) is an oil-soluble UVB-absorbing UV filter derived from PABA (para-aminobenzoic acid). It was once one of the most common UVB filters in US sunscreens but has declined in use since the 1990s.

Documented risks

Ensulizole: Ensulizole is approved by the FDA at up to 4% and in the EU at up to 8%. It is water-soluble and less likely to cause sensitivity reactions than oil-soluble filters. Minimal systemic absorption is documented. No established carcinogenicity or endocrine disruption. As with other UV filters, phototoxicity and photocontact dermatitis are very rare possibilities.

Padimate O: Padimate O is FDA-approved at up to 8%. It is a PABA derivative and carries a rare risk of photoallergic contact dermatitis in individuals sensitive to PABA-related compounds. There are some in vitro studies suggesting potential DNA damage from padimate O under UV exposure, though this has not been substantiated in human studies at cosmetic use levels. The CIR has assessed it as safe. Its use has largely been replaced by more modern, better-tolerated filters.