Sodium metabisulfite

Buyers must distinguish between Food Grade (E223) and Industrial Grade. Key parameters include Purity (typically ≥96-98%), Iron (Fe) content (<10-50ppm), and Heavy Metal content. For food applications, ensure it meets FCC (Food Chemicals Codex) or JECFA standards. For industrial use, such as water treatment or mining, the SO2 (Sulfur Dioxide) evolution rate and solubility are critical performance indicators.

Ensure the supplier provides a valid COA (Certificate of Analysis) for every batch. For food-grade exports, HACCP, ISO 22000, or KOSHER/HALAL certifications are often required. Because it is a chemical product, a comprehensive MSDS (Material Safety Data Sheet) is mandatory for customs clearance and logistics handling to ensure safety protocols are met.

Sodium Metabisulfite is sensitive to moisture and oxidation. It should be stored in a cool, dry, and well-ventilated area. Exposure to air will lead to the release of toxic sulfur dioxide gas and degradation into sodium sulfate. Ensure the supplier uses moisture-proof packaging, typically PE-lined PP woven bags or kraft paper bags, to maintain a shelf life of at least 12-24 months.

It is widely used as a preservative and antioxidant in the food industry (dried fruits, wine, seafood). In industrial sectors, it serves as a dechlorinating agent in water treatment, a reducing agent in chemical synthesis, and a depressant in the mining flotation process. Identifying the specific application helps the supplier recommend the correct particle size (powder vs. crystalline).

Sodium Metabisulfite is classified under UN 2693 (Class 8 Corrosive) or sometimes handled as non-hazardous depending on concentration and local regulations. You must verify the IMO Class with the shipping line. Ensure the supplier provides seaworthy packaging and utilizes desiccants in containers to prevent caking during long-transit maritime shipping.

Utilize secure payment methods and prioritize suppliers on Made-in-China.com who have undergone Audited Supplier verification. Request a pre-shipment inspection (PSI) by third parties like SGS or Intertek to verify the purity and weight before the final balance is paid. This prevents the risk of receiving sub-standard industrial grade instead of food grade.

Chemical prices are highly sensitive to raw material costs (Sulfur and Soda Ash) and environmental regulation shifts in China. Negotiate based on volume tiers (e.g., 20ft FCL vs. LCL) and consider long-term supply contracts to hedge against price volatility. Always ask for FOB or CIF quotes to compare total landed costs effectively.

Check for Anti-dumping duties in your specific country, as some regions impose tariffs on Chinese chemical exports. Ensure all HS Codes (typically 2832.10) are correctly declared on the Commercial Invoice and Packing List to avoid customs delays or fines related to misclassification of hazardous materials.