Sodium hydrosulfide

Sodium hydrosulfide (CAS 16721-80-5), also known as sodium sulfhydrate and commonly abbreviated as NaHS, is an inorganic sulfide salt used as a reactive sulfur source and chemical intermediate.

Where is Sodium hydrosulfide used?

• Mining and metals processing: selective flotation depressant
• Metal sulfide precipitant to recover copper, zinc, and other non-ferrous metals from ore slurries
• Pulp and paper: kraft cooking liquor to improve pulping efficiency and delignification rates
• Leather processing: depilatory agent to remove hair from hides during the beamhouse stage
• In wastewater treatment it precipitates heavy metals from industrial effluent streams.
• Deoxygenation of injection water to reduce underground arsenic mobilization in aquifer storage and recovery.
• Preparation of thioglycolic acid.
• Production of flame retardant resins.
• Chemical building block for polyphenylene sulfide (PPS) and polysulfides.

Formulation notes

• Unlike sodium sulfide (Na2S), NaHS is a 1:1 electrolyte and is more soluble.
• Hydrogen sulfide (H2S), a toxic gas, is evolved upon contact with acids.
• Mildly corrosive to carbon steel and cast iron; very resistant to stainless steels; rapidly attacks copper and its alloys, aluminum and zinc; PVC storage systems should be avoided.

Typical specification

• pH of 11.5 to 12.5.

Regulatory status

• UN number 2318 refers to sodium hydrosulfide with less than 25% water of crystallization; hazard class 4.2, packing group II.

Storage, packaging and handling

• Should be stored dry in a well-ventilated room, separated from acids and strong oxidants.
• Available in flakes or as a solution in drums, IBCs/totes and bulk for industrial users.

Frequently asked questions about Sodium hydrosulfide

Under which HS code is the solid form classified?

The solid form is classified under HS 2830.10 (sodium sulfides).

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.