sodium metabisulphite

– product identification
cas no. : 7681-57-4
einecs no. : 231-673-0
h.s. code : 2832.1000
formula : na2s2o5
molecular weight : 190.10
synonyms : dinatriumdisulfit; disulfito de disodio; disulfite de disodium; disodium disulfite; disodium salt pyrosulfurous acid; disulfurous acid, disodium salt; pyrosulfurous acid, disodium salt; sodium metabisulfite; sodium disulfite; sodium pyrosulfite;

– physical and chemical properties
physical state : white or yellowish crystal powder
melting point : 150 c (decomposes)
specific gravity : 1.48
solubility in water : 54 g/100ml (20 oc); 81.7 g/100ml (100 oc)
nfpa ratings : health: 2; flammability: 0; reactivity: 0
stability : stable under ordinary conditions

– applications
 industrial grade :
– printing dyeing mordant, dechlorinating agent for washed fabric.
– medical deoxidizer and sulfonating agent.
– bleaching agent of bamboo, wood and paper fiber.
– non-ferrous mineral separation agent.
– waste water disposing agent.
– rubber coagulator.
– alkyl spice aldehyde in spice industry.
– depilating agent, softening agent and anti-wear agent in leather industry.
– reducer of developer and protective agent of fixative in sensitization industry.
 food grade :
– bleaching agent ( sugar, pastry, water-soaked bamboo slices, mushrooms, etc ).
– loosening agent ( bread, biscuit, etc ).
– corrosion protection antiseptic ( fruit juice, can, brewing, grain storage, etc ).
– antioxidant and fresh keeping agents ( lily flower, sea food, fruit, vegetables, etc ).

– specification
testing items / quality standard (food grade) / quality standard (industrial grade)
purity – na2s2o5 : 96.5% min / 96.5% min
water insoluble : 0.05% max / 0.05% max
iron (fe) : 0.003% max / 0.005% max
arsenic (as) : 0.0001% max / 0.0001% max
heavy metal (pb) : 0.0005% max / –
clarity : pass / –

– transportation
storage : store in a cool, dry, well-ventilated warehouse.
packing : in 25kgs /50kgs /1000kgs net p.p. woven bags