Selenium and its compounds are on the Community Right-To-Know List. Reported in EPA TSCA Inventory.

OSHA PEL: TWA 0.2 mg(Se)/m³
ACGIH TLV: TWA 0.2 mg(Se)/m³
DFG MAK: 0.1 mg(Se)/m³
DOT Classification:  6.1; Label: Poison

The Selenium(IV) disulfide (1:2) with CAS registry number of 7488-56-4 is also called selane, thioxo-, sulfide. Its EINECS registry number is 231-303-8. The IUPAC name is thioxoselane sulfide. In addition, the molecular formula is S₂Se and the molecular weight is 143.09. It is a kind of orange to reddish-brown powder and belongs to the class of Inorganics.

Preparation and uses of Selenium(IV) disulfide (1:2): it can be prepared by seleniousic acid and hydrogen sulfide. Add sodium hydrogen seleniousoate into acetic acid solution at first. Next, add Na₂S·10H₂O into methanol aqueous solution. Then add sodium sulfide solution into sodium hydrogen seleniousoate solution at reaction temperature of 4-6 °C. The reaction can generate orange precipitation. By washing and drying the precipitation you can get the product. And it can be used for the treatment of tinea versicolor, head seborrheic dermatitis, scurf and multiple color skin tinea.

When you are using this chemical, please be cautious about it as the following:
It has danger of cumulative effects. And it is toxic by inhalation and if swallowed. Moreover, it is very Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. When you are using it, do not eat, drink or smoke. After contact with skin, wash immediately with plenty of ... (to be specified by the manufacturer). In case of accident or if you feel unwell, seek medical advice immediately (show label where possible). This material and/or its container must be disposed of as hazardous waste. In addition, you should avoid release to the environment. And you can refer to special instructions safety data sheet.

You can still convert the following datas into molecular structure:
(1)SMILES: S=[Se]=S
(2)InChI: InChI=1/S2Se/c1-3-2
(3)InChIKey: JNMWHTHYDQTDQZ-UHFFFAOYAE

The toxicity data is as follows: