Appearance A clear colorless liquid Assay 69 - 72% Weight/ mL at 20°C 1.41 - 1.42 g Non volatile matter Max 0.01% Hydrochloric acid (HCI) Max 0.005% Sulphuric acid (H2SO4) Max 0.01% Arsenic (As) Max 0.0001% Iron (Fe) Max 0.005% Lead (Pb) Max 0.0005%