Buying Xanthan Gum: What Matters
Xanthan gum (CAS 11138-66-2) is a commodity hydrocolloid, but two suppliers’ materials can behave very differently in the same formulation. The name on the bag tells you little; what matters is the grade, the specification, the mesh size and the consistency of supply. This guide explains what to look for when buying xanthan gum, how to read a certificate of analysis (COA), and the questions worth asking a supplier before you place an order.
For the technology behind the numbers, see our main article on xanthan gum (CAS 11138-66-2).
Step 1: Match the Grade to the Application
Xanthan gum is sold in several grades that differ mainly in regulatory category, purity and clarity. Buying the wrong grade is the most common and most expensive mistake.
| Grade | Standard | Best for |
|---|---|---|
| Food grade | E415 / FCC | Food and beverage; the largest volume |
| Pharmaceutical grade | USP / EP / NF | Suspensions, syrups, gels and tablets |
| Oilfield / technical grade | Supplier specification | Drilling, completion and EOR fluids |
| Clarified / transparent grade | Food or cosmetic | Clear beverages, transparent gels |
Step 2: Read the Specification, Not Just the Purity
A xanthan specification contains several numbers that are more decision-relevant than purity. The table below lists the parameters to check, using the PolyBlueChem food/API grade as an example.
| Parameter | Why it matters | Example value |
|---|---|---|
| Viscosity (1% in 1% KCl) | The headline performance figure; drives use level | 1,300–1,700 cP |
| Shearing ratio | How strongly pseudoplastic the sample is; affects suspension | ≥ 6.5 |
| Pyruvic acid | Relates to viscosity and interaction with salts | ≥ 1.5% |
| pH (1% solution) | Confirms the material is neutral to mildly alkaline | 6.0–8.0 |
| Loss on drying | Moisture; affects stability and weight | ≤ 13.0% |
| Ash | Residual salts | ≤ 13.0% |
| Heavy metals (as Pb) | Compliance and safety | ≤ 20 ppm |
| Microbiology (TPC, yeasts, moulds, E. coli, Salmonella) | Food/pharma safety | See COA |
For food and pharmaceutical buyers the microbiological limits and heavy-metal results are as important as viscosity. For industrial buyers viscosity, shearing ratio and mesh size usually drive the decision.
Step 3: Choose the Right Mesh Size
Particle size affects how fast the powder hydrates and how easily it disperses.
- 200 mesh (finer): hydrates and disperses more quickly; preferred for cold-process, continuous and food applications where lump-free dissolution matters.
- 80 mesh (coarser): common in drilling fluids and general industrial use, where slower hydration is acceptable and dust is easier to manage.
Where lump-free hydration is critical, ask whether a dispersible (coated) grade is available.
Step 4: Understand Packaging and Shelf Life
Xanthan gum is typically packed in 25 kg multiwall paper bags or fibre drums with an inner liner. It is hygroscopic, so moisture-tight packaging and dry storage matter. Confirm the packing that suits your plant, the net weight per unit, and the recommended shelf life. Ask for the material’s storage guidance (cool, dry, sealed) and, for food use, the production date and best-before information.
Supplier Checklist
Before placing an order, get satisfactory answers to these questions:
- Grade and standard. Which grade, and does it meet E415/FCC, USP/EP, or an oilfield specification?
- COA per batch. Will a certificate of analysis accompany each shipment, and can you see a recent example?
- Documentation. Are an SDS, and where needed, REACH, halal, kosher, non-GMO and allergen statements available?
- Consistency. How is viscosity controlled and standardised batch to batch?
- Mesh size and form. 80 or 200 mesh, and is a dispersible grade available?
- Packaging. What unit sizes and packaging types are offered?
- Lead time and terms. What is the typical lead time, minimum order quantity and Incoterm?
- Traceability. Can the material be traced to a production batch and site?
Common Buying Mistakes
- Buying on price alone. A cheaper material with a lower viscosity or shearing ratio may need a higher use level, erasing the saving.
- Assuming all grades are interchangeable. Food, pharmaceutical and oilfield grades are not interchangeable; documentation and purity requirements differ.
- Ignoring mesh size. The wrong mesh size can cause dispersion problems that show up only in production.
- Not sampling before a large order. Viscosity and hydration behaviour should be bench-tested in your own system before scaling up.
- Overlooking storage. Poorly stored powder can pick up moisture and lump, so packaging and storage discipline matter as much as the product.
How PolyBlueChem Can Help
PolyBlueChem supplies xanthan gum (CAS 11138-66-2) in food grade and API grade, at 80 mesh and 200 mesh, conforming to the standard of E415 and the FCC. We can provide current specifications and a COA, discuss the grade that fits your application, and quote a range of packaging and shipping options. To request specifications, a sample or a quotation, contact the PolyBlueChem team.
Frequently Asked Questions
What should I look for when buying xanthan gum?
Match the grade to your application (food, pharmaceutical, oilfield or clarified), check viscosity and shearing ratio rather than purity alone, choose the right mesh size, and confirm the supplier provides a per-batch COA and the documentation you need.
Does 80 or 200 mesh xanthan gum matter?
Yes. Finer 200 mesh hydrates and disperses faster and suits cold and continuous processes; coarser 80 mesh is common in drilling fluids and general industrial use.
Is food grade xanthan gum the same as oilfield grade?
No. They differ in purity, documentation and sometimes hydration behaviour, and are not interchangeable for regulated uses.
What documents should come with a shipment?
At minimum a certificate of analysis (COA) and a safety data sheet (SDS). For regulated markets, ask for REACH, halal, kosher, non-GMO or allergen statements as applicable.
How should xanthan gum be stored after purchase?
Keep it cool, dry and in the sealed original packaging. It is hygroscopic and absorbs moisture from the air, which can cause lumping.