Use: 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.

Photo grade:
1) Appearance: white needle crystal
2) Assay: 99.0-101.0%
3) Melting point: 171-175oC
4) Solubility: qualified
5) Residue on ignition: 0.05% max
6) Heavy metal (as Pb): 0.002% max
7) Iron (Fe): 0.002% max

Technical grade:
1) Appearance: grey or yellowish powdery crystal
2) Assay: 99.0% min
3) Melting point: 169.5oC min
4) Residue on ignition: 0.3% max

Packing:
25kg/PP woven bag with kraft paper bag in the middle and two-ply inner PE bag