Chem-Lab brand (CL03.0207.1000) standard buffer solution designed for laboratory use, ideal for calibrating pH meters or maintaining pH in strongly alkaline samples, pH at 20 °C: 12.00 ± 0.02, traceable to NIST standard reference materials (SRM), ensuring high precision, it is a solution of phosphate and sodium hydroxide. It's an odorless, colorless, liquid soluble in water with 100°c boiling point.