Available as colorless solutions (pH 4 with red label, pH 7 with yellow label, pH 10 with blue label) or as color-coded solutions. Can be stored at room temperature. Accurate to ±0.01 pH at 25°C (±0.02 for pH 2, pH 3, pH 4.63, pH 5, pH 6, pH 7.38, pH 8, pH 9, pH 10 and pH 12.45). Labels include lot number and expiration date. Standardized against solutions whose certification is traceable to the National Institute of Standards and Technology. pH 12.45 is standardized against high-purity calcium hydroxide.