White crystalline powder with a slight sulfur dioxide odor, acting as a strong reducing agent.It is stable under normal temperature and dry conditions.It is prone to oxidative decomposition and heat release when exposed to moisture, heat or air, which may cause spontaneous combustion in severe cases.Its aqueous solution is extremely unstable and decomposes rapidly to lose effectiveness.

1. Textile printing and dyeing: reductive dyeing, reductive cleaning, and bleaching of fabrics (silk, wool, nylon, etc.);
2. Paper industry: bleaching agent for wood pulp;
3. Food processing: bleaching of gelatin, sucrose, preserved fruits, etc. (food-grade products must comply with national standard limits);
4. Chemical synthesis: reducing agent for organic dyes and pharmaceutical intermediates;
5. Water treatment: reductive removal of heavy metal ions.