Common cosmetics preservative thatŠ—Ès considered one of the least sensitizing for use in formulations. It does not release formaldehyde. Phenoxyethanol is approved worldwide (including in Japan and in the EU) for use in all types of water-based cosmetics, up to a 1% concentration.
The safety of phenoxyethanol has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel several times. This group evaluated the foundational scientific data plus the newer relevant data, and concluded that phenoxyethanol is safe as a cosmetic ingredient. Interestingly, although the phenoxyethanol used in skincare products is almost always synthetic, this chemical occurs naturally in green tea.
In short, phenoxyethanol is considered a safe and effective preservative when used in amounts approved for use in leave-on or rinse-off cosmetics products.
References for this information:
Cosmetics & Toiletries, 2014, issue 5, pages 24-27
International Journal of Cosmetic Science, April 2011, issue 2, pages 190-196
Acta Anatomica, 1989, issue 2, 155-8