Chemical Specifications Appearance White to creamy white, wax-like solid, crystals or flakes pH (5 % solution) 4.5 - 7.5 Freezing point 56 - 60 deg C Colour of solution (15% in water) Passes test Arsenic (As) Max 0.0003% Heavy metal (as Pb) Max 0.0005% Sulphated ash Max 0.1%