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
Safety data sheets and certificates are available to account holders. Request one below and we send it the same business day — or ask us to attach documents to every shipment automatically so you are not requesting them one at a time.
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. How to read an SDS
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 |
Spill, release, or a container you cannot identify? The emergency line is answered 24 hours a day. Do not move an unknown container.
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