Blue 1 Lake

Blue 1 Lake (the insoluble aluminum salt form of FD&C Blue No. 1) is used as a colorant, typically at very low concentrations, and is generally well-tolerated in leave-on and rinse-off products. However, synthetic dyes can trigger occasional irritation or rare hypersensitivity reactions in highly reactive or eczema-prone individuals, particularly on compromised skin or around the eyes/lips. Given the low usual exposure but non-zero risk in sensitive populations, it fits best as a mild irritant potential ingredient. Safety Notes: Blue 1 Lake (CI 42090:2) is typically used at ultra-low levels in skincare as a colorant/opacifier tweak, with commercial leave-on creams/lotions and cleansers often dosing around ~0.00001–0.01% to achieve a pale tint. Higher concentrations are observed in strongly colored OTC products (e.g., blue-toned masks, styling/edge gels marketed for skin/hairline use, and vivid tinted balms/cream products), where lakes may be pushed into the ~0.1–0.5% range to deliver saturated color and improved bleed resistance versus soluble dyes. Actual allowable use depends on jurisdiction and product category (e.g., general cosmetics vs eye-area or lip products), so brands typically stay within local color additive regulations and impurity limits.