Sodium formaldehyde sulfoxylate dihydrate

Sodium formaldehyde sulfoxylate dihydrate (CAS 6035-47-8), commonly known as SFS, is a reducing agent used industrially for bleaching and stripping color from substrates. Also marketed as Rongalite.

Where is Sodium formaldehyde sulfoxylate dihydrate used?

• Textile processing: discharge agent to remove dye, enabling precise pattern creation without damaging fiber structure
• Pulp and paper: bleaching agent to brighten mechanical and chemical pulps where milder conditions are required
• Leather processing: uniform whitening of hides prior to dyeing, improving final color consistency
• It also functions as a reductive stripping agent in vat and sulfur dye systems, allowing color correction and re-dyeing of off-shade goods.

Commercial specifications

• Purity specifications typically 95% to 98% active content
• Packaging commonly in 25 kg bags or drums, with bulk options