Specification:
Appearance:White needle crystal or powder crystal
Purity:99.5-101.0
Melting Point:171-175
Water:0.3 MAX
Solubility:Transparent without insoluble matter
Residue on ignition ash:0.05 Max
Heavy metalpb:0.002 Max
IRON Fe:0.002 Max
Usage: Can be used as intermediates of polymer, monomer inhibitor, dyes and auxiliary; as antioxidant in food and medicine industry; as anti coagulant for gas; developer for film, photos and X-ray film.