When buying chitosan (CAS 9012-76-4), one of the first questions is irradiated or non-irradiated. The choice depends on the end use and regulatory requirements. This guide explains the difference, the specification items that matter, and how to order the right grade.
1. Irradiated vs Non-irradiated Chitosan
| Aspect | Non-irradiated | Irradiated |
|---|---|---|
| Sterilization | None (process hygiene) | Gamma/e-beam sterilized |
| Typical use | Water treatment, cosmetics, food, agriculture | Pharmaceutical, medical, sterile applications |
| Microbial spec | TPC 5000 cfu/g max, pathogens negative | Sterility assured (SAL dependent) |
| Dosing | Standard | May show slight viscosity change after irradiation |
PolyblueChem supplies both grades – please state irradiated or non-irradiated when ordering.
2. Reading the Non-irradiated Specification
| Parameter | Value | Why it matters |
|---|---|---|
| Appearance | Off-white or light yellow powder | Visual QC |
| DAC degree | 90% min | Activity and solubility |
| Viscosity | 200 mPa.s max | Molecular weight indicator |
| Moisture | 10% max | Stability, dosing |
| Ash | 1.5% max | Mineral purity |
| pH | 6.5-8.5 | Formulation compatibility |
| Acid-insoluble substance | 1.0% max | Insoluble residue |
| As / Pb / Hg / Cd | 0.5 ppm max each | Heavy-metal safety |
| Heavy metals | 10 ppm max | Safety limit |
| Total plate count | 5000 cfu/g max | Microbial quality |
| Yeast & Mold | 100 cfu/g | Microbial quality |
| E. coli / Salmonella / S. aureus | Negative | Pathogen safety |
3. Ordering Checklist
- State grade: DAC, viscosity target, irradiated or non-irradiated.
- Request COA with measured heavy metals and microbiology.
- Confirm packaging (25 kg drums/bags) and shelf life.
- For pharma/medical use, request the irradiated grade and documentation.
4. FAQ
Can I use non-irradiated chitosan in cosmetics?
Yes – cosmetic, food, water and agricultural applications normally use the non-irradiated grade.
Does irradiation change the product?
Gamma irradiation may slightly lower viscosity; specify your acceptable range when ordering irradiated grade.
5. References and Further Reading
- Supplier COA and MSDS for the specific grade quoted.
This article is published for industrial and technical reference by PolyblueChem. Verify against the supplier’s COA and applicable standards.
See our chitosan chemistry and production guide and the water treatment guide. PolyblueChem supplies chitosan (CAS 9012-76-4) in irradiated and non-irradiated grades – contact us for specifications and quotations.