Calamine

Calamine (primarily zinc oxide with a small amount of ferric oxide) is used topically in lotions/suspensions (commonly ~5–15%) as a soothing, antipruritic skin protectant and is generally well-tolerated even in eczema-prone skin. Clinically, true irritant reactions are uncommon, but dryness, transient stinging on fissured/compromised skin, or mechanical irritation from a drying, particulate film can occur, and rare contact allergy has been reported. Given its overall safety profile but non-zero risk in compromised barriers, it best fits a 'gentle' irritancy score. Safety Notes: In consumer skincare, calamine is used at very low levels (around 0.05–0.5%) as a soothing/anti-redness adjunct in lotions, creams, and masks where it functions mainly as a mild absorbent/opacifier. Mainstream OTC calamine anti-itch lotions are commonly formulated around 8% calamine, and the highest consumer-available leave-on suspensions/lotions and pastes are typically ~10–15% (often paired with zinc oxide), as higher loads become excessively chalky, unstable, and difficult to spread. Rinse-off products generally sit at the lower end since calamine’s benefit is primarily from leave-on contact time.