Alcohol

In cosmetics, “Alcohol” typically refers to ethanol/SD alcohol used at meaningful levels (often ~5–30%+) as a solvent and quick-dry vehicle, which can strip lipids, increase transepidermal water loss, and cause stinging—especially on compromised barriers (eczema, post-procedure) and around the eyes. Clinical experience and patch/usage testing consistently show higher rates of burning/irritant dermatitis with denatured alcohol-containing leave-on products, and it can amplify irritation from other actives in a routine. Given the predictable barrier disruption and frequent intolerance in sensitive populations, I score it as a significant irritant risk at typical functional concentrations. Safety Notes: In commercial skincare, very low levels (~0.1–2%) are used as solvents for fragrance/extracts or to aid preservative performance in both leave-on and rinse-off products, including many “alcohol-free” items that still contain trace/processing alcohol. At the high end, consumer-available astringents, aftershaves, and acne antiseptic/toner-type products commonly reach ~40–70% alcohol, and some OTC antiseptic skin cleansers/hand-sanitizer-style products marketed for skin use can approach ~80–90% ethanol/isopropyl alcohol (highest typically in leave-on antiseptic formats rather than standard facial moisturizers).

Suitability