The safety of zinc phenolsulfonate has been assessed by the Expert Panel for Ingredient Safety. The Expert Panel evaluated the scientific data and concluded that zinc phenolsulfonate was safe as a cosmetic ingredient. In 2004, as part of the scheduled re-evaluation of ingredients, the Expert Panel considered available new data on this ingredient and reaffirmed the above conclusion.
The Expert Panel noted that zinc phenolsulfonate is moderately toxic when administered orally; however, in tests, no significant toxicity was reported when zinc phenolsulfonate was applied dermally in acute and subchronic studies.
A single insult patch test of a 5% aqueous zinc phenolsulfonate solution was negative for skin irritation. Minimal skin irritation was reported when 100% zinc phenolsulfonate was tested. A test for delayed sensitization was also negative.
No ocular irritation was observed with a 5% aqueous solution. No mutagenicity was observed when zinc phenolsulfonate was tested in a bacterial assay. Clinical assessment of zinc phenolsulfonate in product formulations indicated that zinc phenolsulfonate was at most a mild skin irritant in normal use, but not a sensitizer.
The European Union allows the use of zinc phenolsulfonate in deodorants, antiperspirants and astringent lotions at concentrations up to 6% of the anhydrous substance (see Annex III).
Link to the EU Cosmetic Regulation: