Caustic Soda Flakes: Grades, Specifications and Supply
We supply one product family, in two export grades and two packing formats. Everything below is the same material — caustic soda flakes, sodium hydroxide, NaOH — separated only by purity and how it is packed for shipment.
Also searched as: lye, soda lye, sodium hydrate, white caustic, flake caustic, NaOH flakes · CAS 1310-73-2 · HS 2815.11.
Grade comparison
| Parameter | Grade 99% min (main grade) | Grade 98% min (on request) |
|---|---|---|
| NaOH content | ≥ 99.0% | ≥ 98.0% |
| Sodium carbonate (Na2CO3) | ≤ 0.8% | ≤ 0.8% |
| Sodium chloride (NaCl) | ≤ 0.05% | ≤ 0.05% |
| Iron oxide (Fe2O3) | ≤ 0.008% | ≤ 0.008% |
| Appearance | White flakes | White flakes |
| Typical use | Tighter specifications: pulp and paper, textiles, fine chemical processing | Water treatment, detergents, general chemical processing |
Latest independent test results
In March 2026 a production sample of our solid sodium hydroxide was tested by the Tianjin Product Quality Inspection Technology Research Institute, a CMA- and CNAS-accredited laboratory (report TQT03-1051-2026, against GB/T 209-2018). Every item passed with margin:
| Test item | GB/T 209-2018 limit (IS-I) | Result | Evaluation |
|---|---|---|---|
| Appearance | White, lustrous solid | White, lustrous solid | Pass |
| NaOH content | ≥ 98.0% | 99.1% | Pass |
| Sodium carbonate (Na2CO3) | ≤ 0.8% | 0.3% | Pass |
| Sodium chloride (NaCl) | ≤ 0.05% | 0.01% | Pass |
| Iron oxide (Fe2O3) | ≤ 0.008% | 0.0006% | Pass |
Sample received 19 March 2026, tested 23–25 March 2026, report issued 26 March 2026. A copy of the full report is available with your enquiry.
Supply and packing at a glance
- Forms: white flake caustic soda, 99% min (main grade) and 98% min on request.
- Packing: 25 kg PP/PE laminated bags; 1 MT jumbo bags with lifting loops.
- Loading: typically 25 MT per 20' FCL — see packing and container loading.
- Origin: Wuhai, Inner Mongolia — the Chinese chlor-alkali cluster for flake caustic soda.
- Documents: COA, MSDS and full export documentation — see quality and documents.
- Food grade: the plant holds a Food Additive Production Licence (SC20115030302021) — mention food-grade requirements in your enquiry.
Which grade should you choose?
Grade 99% min (main grade)
Our standard production grade: water and effluent treatment, pulp and paper, textile mercerising, soap and detergent production, and general chemical synthesis.
Grade 98% min (on request)
For buyers whose process tolerates a wider carbonate, chloride or iron range and who want the most competitive price. If your specification sheet sets tighter limits, send it to us — we confirm against the plant before quoting.
Applications
Flake caustic soda is a raw material, not a finished product. Our buyers use it in:
Water & effluent treatment
pH correction and neutralisation of acidic waste streams.
Soap & detergents
Saponification and the production of cleaning formulations.
Textiles
Mercerising and scouring of cotton fibres.
Pulp & paper
Pulping and process chemistry control.
Alumina & metals
Bauxite processing and metal surface cleaning.
Chemical synthesis
Neutralisation and intermediate production.
Request the full specification
Send us your target grade and destination port and we will return the specification sheet, packing options and an indicative offer. If you hold a formal specification sheet of your own, send it with your enquiry and we will confirm compliance before quoting.
Product questions
Is flake caustic soda the same as pearl or liquid caustic soda?
They are the same chemical, sodium hydroxide. Flakes are the form we supply. Pearl and liquid forms exist but are handled differently, so tell us if your process needs them and we will confirm what we can offer.
Can you meet a specification sheet issued by my own laboratory?
Send it with your enquiry. We check it against plant production output before quoting, so you do not receive an offer we cannot actually fulfil.
How is the product stored and transported?
Caustic soda flakes are hygroscopic and corrosive, so they are shipped in sealed PP/PE laminate bags and handled as UN 1823, Class 8 material. Full handling guidance is in the MSDS.
Request a quotation
Send us your required grade, quantity and destination port. We reply with an indicative price, packing options and a specification sheet — normally within one working day.