How do food-grade and wastewater-grade sodium acetate differ in quality specs and supplier selection?

How do food-grade and wastewater-grade sodium acetate differ in quality specs and supplier selection?
The market clearly separates food-grade anhydrous sodium acetate (99% min, CAS 127-09-3) from industrial trihydrate (58-60% sodium acetate content, CAS 6131-90-4). Food-grade material must meet GB 30603-2014, with strict limits on heavy metals and microbes, and is used in pH buffering, preservation, and feed acidification. Wastewater-grade trihydrate prioritizes stable COD equivalent — typically 440,000 mg/L or higher — and low water insolubles for denitrification efficiency. Reputable suppliers run physically isolated production lines and warehouses to prevent cross-contamination, provide batch COA reports with full parameters, and support custom packaging from 25 kg bags to ton bags. Buyers should verify production licenses, third-party test reports, and export documentation readiness, especially for municipal tenders or overseas orders.