Choose the grade first
Sodium bicarbonate (NaHCO₃, CAS 144-55-8) is supplied against several distinct specifications. They overlap heavily on assay and diverge on the controls and documentation behind them.
| Grade | Assay | Specified against | Typical use |
|---|---|---|---|
| Food | ≥99.0–99.5% | FCC / E500ii | Baking, food processing, beverages |
| Pharmaceutical | ≥99.0–99.5% | BP / USP / EP | Antacids, dialysis, effervescent tablets |
| Feed | ≥98.5% | Feed specification | Rumen buffer for dairy and beef cattle |
| Technical | ≥98.5% | Industrial | Water treatment, flue gas cleaning, cleaning products |
Pharmaceutical grade is the tightest. If you are formulating against a monograph, the certificate needs to report the monograph parameters, not a general assay.
| Parameter | BP/USP limit |
|---|---|
| NaHCO₃ content | 99.0–101.0% on the dried basis |
| pH (5% solution) | 8.3 |
| Chloride (as Cl) | ≤150 ppm |
| Sulphate (as SO₄) | ≤150 ppm |
| Arsenic | ≤3 ppm |
| Heavy metals (as Pb) | ≤5 ppm |
| Loss on drying | ≤0.25% |
Then choose the particle size
Particle size is a separate decision from grade, and it is the one most often left off a purchase order. It governs dissolution rate, flow behaviour, dust generation and how the material behaves in a blend.
- Fine powder, under about 100 microns — fast dissolution, used in effervescent formulations and dry-mix baking powder; generates the most dust
- Standard powder — the general-purpose option for food and technical use
- Coarse granular, roughly 0.5–2 mm — low dust, free flowing, preferred for feed blending and bulk industrial dosing
- For flue gas treatment, fine milled material is used deliberately because surface area drives reaction rate
Key physical properties
| Property | Value |
|---|---|
| Chemical formula | NaHCO₃ |
| CAS number | 144-55-8 |
| Molecular weight | 84.01 g/mol |
| Appearance | White crystalline powder or granules, odourless |
| pH (1% solution) | 8.3 — mildly alkaline |
| Decomposition | Begins 50–80 °C; complete above 100 °C |
| Density | 2.20 g/cm³ |
| Bulk density | 550–1,000 kg/m³ depending on grade and particle size |
| Solubility in water | 9.6 g/100 mL at 20 °C; 16.4 g/100 mL at 60 °C |
The decomposition problem
Sodium bicarbonate does not melt. It decomposes, beginning as low as 50 °C, into sodium carbonate, water and carbon dioxide. That is the property the baking industry relies on — and the one that quietly ruins material stored badly.
- A warehouse under a metal roof in a Pakistani summer can exceed 50 °C, so storage location matters as much as packaging
- Partial decomposition raises pH and reduces available CO₂, which shows up as poor rise in baking and weaker buffering in feed
- It is not visible — decomposed material looks identical, which is why assay on receipt is worth doing for critical applications
- Never store near steam lines, ovens, direct sunlight or any heat source
- Keep it dry as well; moisture accelerates the same breakdown
Where it is used, and what that implies for grade
For Pakistani buyers the fastest-growing application is feed grade, used as a rumen buffer in dairy and beef cattle. Dosing is well established.
| Animal | Typical daily dose | Purpose |
|---|---|---|
| High-yielding dairy cow or buffalo | 100–200 g/day | Rumen buffering, maintaining milk fat |
| Growing beef cattle | 50–100 g/day | Feed conversion, acidosis prevention |
| Sheep and goats on concentrate | 5–15 g/day | Rumen pH stabilisation |
| Poultry under heat stress | 0.1–0.3% of feed | Electrolyte balance |
- Food and baking — the raising agent in baking powder, activated by an acid component
- Pharmaceutical — antacids, dialysis concentrate, IV solutions and effervescent tablets, against BP or USP grade
- Water treatment — raising alkalinity and stabilising pH without the aggressiveness of caustic soda
- Flue gas treatment — dry sorbent injection to remove acid gases
- Cleaning products and mild abrasives, and dry chemical fire suppression
What to put on the RFQ
- Grade and monograph — "food grade, FCC" or "BP grade", not "pure sodium bicarbonate"
- Particle size or mesh specification, stated separately from grade
- Assay and loss on drying limits
- Quantity per delivery and annual volume
- Pack — 25 kg bags, jumbo bags — and whether you need moisture-barrier lining
- Delivery city and whether the store is temperature-controlled
- Documentation — batch COA naming the monograph, MSDS, and for feed use the relevant feed compliance paperwork
What drives the price
- Grade, with pharmaceutical material carrying a substantial premium over technical for the same assay
- Soda ash and CO₂ input costs, since most bicarbonate is made by carbonating soda ash solution
- Particle size, where tightly controlled fine or granular fractions cost more than standard powder
- Pack format and whether moisture-barrier packaging is required
- Freight and delivery city
- Exchange rate and duty, as Pakistan is largely supplied by import
Sourcing considerations in Pakistan
- Most industrial and food-grade bicarbonate is imported, so confirm lead time alongside price
- It is not a dangerous good for transport, which keeps logistics simple
- For feed use, confirm the material is supplied and documented as feed grade — food grade is acceptable chemically but the paperwork differs and matters at audit
- For pharmaceutical use, retain the monograph reference and batch certificate in the purchase record