Sodium Bicarbonate Grades: Food, Pharma and Technical
Sodium bicarbonate is unusual among bulk chemicals in how far its end uses diverge. The same compound leavens bread, buffers a dialysis circuit, scrubs acid gas from an incinerator flue and supplements cattle feed. Those applications are governed by entirely different standards, and the difference between grades is not a matter of degree — it is a matter of which regulatory framework the batch was manufactured and tested against. This guide covers what separates the grades and what to verify before you commit.
What is sodium bicarbonate?
Sodium bicarbonate is NaHCO3, CAS 144-55-8 — a white crystalline powder, mildly alkaline and readily soluble in water. It is the compound sold domestically as baking soda, and industrially as sodium bicarbonate or bicarb.
Its defining industrial property is thermal decomposition: on heating it releases carbon dioxide and water, leaving sodium carbonate behind. That single reaction explains most of its uses — the gas evolution that leavens a dough is the same chemistry that makes it an effective dry sorbent for acid gases and an effective dry-powder fire-extinguishing agent. It also means the material must be stored cool and dry, because heat and humidity degrade it in storage rather than merely making it awkward to handle.
What are the grades of sodium bicarbonate?
The compound is identical across grades. What differs is the standard the batch is manufactured and tested against, the impurity limits that standard imposes, and the documentation and facility controls behind it.
- Technical grade is NOT "food grade without the paperwork". A pharmacopoeial or food grade carries tested limits on heavy metals and other impurities, and is produced under facility controls an industrial grade makes no claim to.
- Substituting downward is a compliance failure that may be undetectable in the finished product and entirely visible in an audit.
| Grade | Governed by | Typical use |
|---|---|---|
| Food | Food-additive standards (E500ii in the EU system); FCC | Leavening, effervescent products, food processing |
| Pharmaceutical | A pharmacopoeia — IP, BP, USP or EP | Formulation, haemodialysis concentrate, antacids |
| Technical / industrial | Supplier specification | Flue gas treatment, pH correction, cleaning, fire extinguishers |
| Animal feed | Feed-grade regulation | Rumen buffer in cattle and poultry feed |
Which grade do you need?
Work backwards from what your finished product is audited against, not from what your process appears to tolerate.
- Anything entering food, or contacting it: food grade, against a named standard. "Food grade" as a bare description on a quotation is not a specification.
- Anything entering a pharmaceutical or medical process, including dialysis concentrate: pharmacopoeial grade, and confirm WHICH pharmacopoeia — IP, BP, USP and EP are separate standards, and an audit will ask for the one your dossier names.
- Flue gas treatment, pH correction, cleaning formulations, fire extinguishers: technical grade, where particle size and reactivity usually matter more than trace impurities.
- Animal feed: feed grade under the applicable feed regulation. Human food grade is not automatically permissible in feed, and the reverse is certainly not.
What is sodium bicarbonate used for industrially?
Beyond the familiar food applications, two industrial uses drive most bulk demand.
| Application | Role |
|---|---|
| Flue gas treatment | Dry sorbent injection — neutralises acid gases such as HCl and SO2 in incinerator and industrial flue streams |
| Haemodialysis | Bicarbonate concentrate for dialysate preparation (pharmacopoeial grade) |
| Animal feed | Rumen buffer, supporting digestion and milk yield in dairy cattle |
| Water and effluent treatment | Mild alkali for pH correction, gentler and more buffered than caustic soda |
| Fire extinguishers | Dry chemical extinguishing agent |
| Cleaning and abrasives | Mild abrasive and alkaline cleaner, including soda blasting |
What to verify before you buy
For technical grade the checks are ordinary commodity checks. For food, pharma or feed grade, the documentation is the product — a batch you cannot evidence is a batch you cannot use.
- The named standard, in writing, on the COA — not "food grade" or "pharma grade" as a description.
- Assay, plus the impurity limits that standard requires (heavy metals, chloride, sulphate, insolubles as applicable).
- Particle size, where the application depends on it — flue gas treatment does, leavening often does.
- Moisture, and the storage conditions the material has actually been held in. Sodium bicarbonate degrades with heat and humidity, so a compliant batch stored badly is no longer a compliant batch.
- Batch number matched to your invoice and to the bag. For a regulated end use this is the traceability link an auditor will follow.
- Shelf life and the manufacturing date, for the same reason.
Frequently asked
What is the CAS number of sodium bicarbonate?
Sodium bicarbonate is CAS 144-55-8. The same CAS number applies across food, pharmaceutical, technical and feed grades, because it identifies the compound rather than the grade or the standard it was tested against.
Is sodium bicarbonate the same as baking soda?
Yes. Baking soda is the common name for sodium bicarbonate (NaHCO3). Industrially the same compound is supplied in several grades, and only a grade meeting a named food standard is appropriate for food use.
Is sodium bicarbonate the same as soda ash?
No. Sodium bicarbonate is NaHCO3; soda ash is sodium carbonate, Na2CO3. They are chemically related — heating sodium bicarbonate drives off carbon dioxide and water and leaves sodium carbonate — but they are different compounds with different alkalinity and are not interchangeable.
Can I use technical grade sodium bicarbonate in food?
No. Technical grade is manufactured to a supplier specification, not to a food-additive standard, and carries no tested limits on the impurities a food standard controls. Food use requires a grade certified against a named standard, and substituting downward is a compliance failure even where the finished product appears unaffected.
What grade of sodium bicarbonate is used for dialysis?
Haemodialysis requires pharmacopoeial grade. Confirm which pharmacopoeia the batch is certified against — IP, BP, USP and EP are separate standards, and your regulatory dossier will name a specific one.
What is sodium bicarbonate used for in flue gas treatment?
It is injected as a dry sorbent into flue gas streams, where it neutralises acid gases such as hydrogen chloride and sulphur dioxide. Particle size matters considerably for this application, because reactivity depends on available surface area.
How should sodium bicarbonate be stored?
Cool, dry and sealed, away from acids and from heat. Heat and humidity degrade it in storage by driving the decomposition to sodium carbonate, so storage conditions affect whether a batch still meets the specification it was certified to — this matters most for food, pharmaceutical and feed grades.
Sources
- PubChem — Sodium bicarbonate (CID 516892) — Substance identity, CAS 144-55-8, physical properties and decomposition — checked 29 July 2026
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