Caustic soda flakes are solid sodium hydroxide (NaOH, ≥99%) produced by evaporating caustic solution and cooling it into thin white flakes. Flakes are the most widely traded solid form of caustic soda: they pack densely, travel well by container and store for long periods in sealed bags. That makes them the usual choice for soap makers, detergent plants, textile mills and buyers importing caustic soda by the container load.
Technical Specifications
| Parameter | Specification |
|---|---|
| Chemical formula | NaOH |
| CAS number | 1310-73-2 |
| UN number / class | UN 1823, Sodium Hydroxide Solid, Class 8 (Corrosive), PG II |
| Appearance | White, opaque flakes |
| Assay (NaOH) | ≥ 99.0% |
| Sodium carbonate (Na₂CO₃) | ≤ 0.5% |
| Sodium chloride (NaCl) | ≤ 0.03% |
| Iron (as Fe₂O₃) | ≤ 0.005% |
Batch-specific results are stated on the Certificate of Analysis supplied with every shipment.
Why Choose Flakes?
- Lowest cost per tonne of NaOH for long-distance shipping, because no water is being transported.
- Long shelf life in moisture-barrier bags, suitable for seasonal or irregular consumption.
- Easy manual handling in 25 kg bags for plants that dissolve caustic in batches.
Main Applications
Soap & Detergent Manufacturing
Used for saponification of oils and fats in bar and liquid soap production, and as an alkali builder in detergent formulations. Consistent assay helps keep finished-product pH stable.
Textile Processing
Used in cotton scouring and mercerisation to improve strength, lustre and dye uptake. Low iron content reduces the risk of fabric discolouration.
Water Treatment
Dissolved on site to prepare caustic solution for pH correction and neutralisation where liquid supply is not practical.
Chemical & Mining Industries
Used in alumina refining, mineral processing and as a reagent in chemical manufacturing.
Packaging, Loading & MOQ
| Loading configuration | Capacity |
|---|---|
| 20ft FCL, floor-loaded | approx. 27 MT (about 1,080 × 25 kg bags) |
| 20ft FCL, palletised | approx. 22–24 MT |
| Minimum order | 1 × 20ft FCL |
- 25 kg PP/PE laminated bags with moisture-barrier inner liner
- 1,000 kg jumbo bags available on request
- UN 1823 Class 8 labelling with GHS pictograms
Storage & Safety
Store in a dry, covered area on pallets, away from acids, aluminium and moisture. Caustic soda absorbs water and CO₂ from air, so reseal opened bags. When dissolving, always add flakes slowly to water, never water to flakes, because the reaction releases significant heat. Wear goggles, face shield and alkali-resistant gloves.
Documentation
- Certificate of Analysis (CoA) per batch
- Safety Data Sheet (SDS), GHS format
- Certificate of Origin and fumigation certificate for export
- ISO 9001 manufacturing certification; REACH information on request for EU shipments
Need a dust-free, free-flowing form for automated dosing? See Caustic Soda Pearls. Prefer a ready-to-pump solution? See Liquid Caustic Soda.
Read our guide: Caustic Soda Flakes vs Pearls vs Liquid: Which Should You Buy?
This product is part of our water treatment chemicals range: coagulants, pH control, disinfection and oxidation from one supplier.
Also used in pulp, paper and textile processing: see our pulp, paper and textile chemicals range.
Request a quote: send us your required quantity, packaging and destination port. Contact our sales team.
