Molecule structure of Arsenic disulfide (CAS NO.56320-22-0):

Molecular Weight: 139.0516 g/mol
Molecular Formula: AsS₂
Exact Mass: 138.865738
MonoIsotopic Mass: 138.865738
Heavy Atom Count: 3
Complexity: 7.5 
Canonical SMILES: S=[As][S]
InChI: InChI=1S/AsS2/c2-1-3
InChIKey: OEXAKCYEHHKCMI-UHFFFAOYSA-N

Hazard Codes of Arsenic disulfide (CAS NO.56320-22-0): T, N
Risk Statements: 23/25-50/53 
R23/25:Toxic by inhalation and if swallowed. 
R50/53:Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment.
Safety Statements: 20/21-28-45-60-61 
S20:When using, do not eat or drink. 
S21:When using do not smoke. 
S28:After contact with skin, wash immediately with plenty of soap-suds. 
S45:In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) 
S60:This material and its container must be disposed of as hazardous waste. 
S61:Avoid release to the environment. Refer to special instructions / safety data sheets.
RIDADR: UN 1557 6.1/PG 2
WGK Germany: 3
Confirmed human carcinogen. A poison. When heated to decomposition it emits toxic vapors of As and SO_x.

OSHA PEL: OSHA: Cancer Hazard
DOT Classification:  6.1; Label: Poison

 Arsenic disulfide (CAS NO.56320-22-0) is also named as Arsenic sulfide (AsS₂) . Arsenic disulfide (CAS NO.56320-22-0) is highly toxic. It can produce toxic flammable gases when it reacts with water or water vapor. The dust is flammable near the fire and heat. It will produce toxic arsenic and sulfur oxide fumes when buring. So the storage environment should be ventilate, low-temperature and dry.