Sodium sulphide is a chemical used in leather, paper and photographic industry. It is also used in water treatment as an oxygen scavenger.  This chemical is dangerous when in contact with moisture in air as it produces hydrogen sulphide a very toxic and flammable gas. Sodium sulphide dangerously reacts with acids evolving hydrogen sulphide hence this must always be kept separated from acids when in transport or during storage.

Packages containing sodium sulphide must always be hermetically sealed to avoid contact with air.

IMDG Code lists Sodium Sulphide as below

1. Class 4.2 (Substances Liable to Spontaneous Combustion) UN 1385 SODIUM SULPHIDE, ANHYDROUS or SODIUM SULPHIDE with less than 30% water of crystallization
2. Class 8 (Corrosive Substances) – UN 1849 SODIUM SULPHIDE, HYDRATED with not less than 30% water

Differences between these two entries are only in their water content.

Click here for Material Safety Data Sheet of Sodium Sulphide