Sodium Metabisulfite
CAS 7681-57-4 · Part MC-SMBS · Technical / Food grade available
Sodium metabisulfite in bags and supersacks. The standard reducing agent for dechlorination and for reducing hexavalent chromium.
Specification
- CAS number
- 7681-57-4
- Part number
- MC-SMBS
- Grade
- Technical / Food grade available
- Physical form
- Solid / powder
- Category
- Dry Chemicals
- Also known as
- SMBS, sodium pyrosulfite, metabisulfite, dechlorination chemical
Sodium metabisulfite, available in technical and food grades.
Typical uses
- Dechlorination ahead of reverse osmosis membranes, which chlorine destroys
- Reduction of hexavalent chromium to trivalent before precipitation
- Neutralising residual chlorine before discharge
- Oxygen scavenging in boiler feedwater
- Preservative in food and beverage, at food grade
Handling
Contact with acid liberates sulfur dioxide gas, which is why metabisulfite must be kept away from acid storage and why an acidic spill into a bag is a serious event rather than a cleanup.
The dry product slowly loses strength on exposure to air. Keep bags sealed. A solution loses strength faster still — make it up fresh rather than holding a dilute tank for weeks.
Sulfite sensitivity is real in a subset of the population. Where dust exposure is possible, ventilation and respiratory protection matter more than the modest hazard rating suggests.
Documents
Available to account holders and sent the same business day. If you need documents routinely, ask us to attach them to your shipping paperwork automatically rather than requesting them one at a time.
Current revision, sixteen-section GHS format
Measured results for the lot you received
Read the sheet before the first use
Section 2 covers the hazards, Section 8 the protective equipment actually required, and Section 10 what this must not be stored next to. Storage incompatibility is the single most common cause of serious chemical incidents.
More in Dry Chemicals
| Product | CAS | Available as | Documents |
|---|---|---|---|
| Sodium Hydroxide Beads, Tech Technical, 99% | 1310-73-2 | 50 lb bag 2 000 lb supersack | SDS · CoA |
| Soda Ash, Dense Technical, 99.2% | 497-19-8 | 50 lb bag 2 000 lb supersack | SDS · CoA |
| Sodium Bicarbonate Technical / Food grade available | 144-55-8 | 50 lb bag 2 000 lb supersack | SDS · CoA |
| Citric Acid, Anhydrous Food grade / USP | 77-92-9 | 50 lb bag 2 000 lb supersack | SDS · CoA |
If your approval process needs something that is not here, one email gets it.
Certificates, insurance, registrations, safety data sheets, and completed supplier questionnaires. Standard documents go out the same business day.