Reported in EPA TSCA Inventory.

DOT Classification:  4.2; Label: Spontaneously Combustible

Sodium sulfide, its cas register number is 1313-82-2. It also can be called Sodium bichromate; and Disodium monosulfide. Sodium sulfide is the chemical compound with the formula Na₂S, or more commonly its hydrate Na₂S·9H₂O. It is a yellow to red solid; readily soluble in water, slightly soluble in alcohol. It is a strong reducing agent and reacts with oxidants. It is used in the production of rubber chemicals, sulfur dyes and other chemical compounds.

Preparation of Sodium sulfide: Industrially Na₂S is produced by reduction of Na₂SO₄ with carbon, in the form of coal:
Na₂SO₄ + 4 C → Na₂S + 4 CO
In the laboratory, the anhydrous salt can be prepared by reduction of sulfur with sodium in anhydrous ammonia. Alternatively, sulfur can be reduced by sodium in dry THF with a catalytic amount of naphthalene:
2 Na + S → Na₂S

Uses of Sodium sulfide: It is primarily used in pulp and paper industry in the kraft process . It is used in water treatment as an oxygen scavenger agent and also as a metals precipitant, in the photographic industry to protect developer solutions from oxidation, in textile industry as a bleaching, as a desulfurising and as a dechlorinating agent and in leather trade for the sulfitisation of tanning extracts. It is used in chemical manufacturing as a sulfonation and sulfomethylation agent. It is used in the production of rubber chemicals, sulfur dyes and other chemical compounds. It is used in other applications including ore flotation, oil recovery, food preservative, making dyes, and detergent. Sodium sulfide is an active ingredient in some over-the-counter ingrown toenail relief products.

When you are using this chemical, please be cautious about it as the following:
1. In case of contact with eyes, rinse immediately with plenty of water and seek medical advice;
2. In case of accident or if you feel unwell, seek medical advice immediately (show label where possible);
3. Avoid release to the environment. Refer to special instructions safety data sheet;

You can still convert the following datas into molecular structure:
(1)InChI=1S/2Na.S;
(2)InChIKey=CXPWOVUZRAFMDA-UHFFFAOYSA-N;
(3)SmilesS([Na])[Na];

The toxicity data is as follows: