IUPAC Name: potassium dihydrogen arsorate 
Molecular Weight: 180.03338 g/mol
Molecular Formula: AsH₂KO₄  
H-Bond Donor: 2
H-Bond Acceptor: 4 
Melting Point: 277-283 °C(lit.)
Density: 2.867
Solubility: clear to very slightly hazy, colorless to faintly yellow
Appreance: white to off-white powder
Merck: 13,7689
Exact Mass: 179.880612
MonoIsotopic Mass: 179.880612
Topological Polar Surface Area: 80.6
Heavy Atom Count: 6 
EINECS: 232-065-8
Complexity: 61.9
Canonical SMILES: O[As](=O)(O)[O-].[K+]
InChI: InChI=1S/AsH3O4.K/c2-1(3,4)5;/h(H3,2,3,4,5);/q;+1/p-1
InChIKey: GVPLVOGUVQAPNJ-UHFFFAOYSA-M
Synonyms of Arsenic acid, monopotassium salt (CAS NO.7784-41-0): Arsenic acid potassium salt ; Potassium dihydrogen arsenate ; Potassium arsenate ; Potassium arsenate monobasic ; Arsenic acid potassium ; Monopotassium arsenate ; Potassium arsenate monobasic anhydrous ; Potassium dihydrogenarsenate , 99.9+%

 Arsenic acid, monopotassium salt (CAS NO.7784-41-0) is used to be pesticides, leather preservation, reagent, optical, electronic materials and so on.

IARC Cancer Review: Human Sufficient Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of chemicals to Man . 23 (1980),p. 39.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) . Reported in EPA TSCA Inventory. ARSENIC and its compounds are on the Community Right-To-Know List.

Confirmed human carcinogen. Mutation data reported. When heated to decomposition it emits toxic fumes of ARSENIC. See also ARSENIC COMPOUNDS. 

Hazard Codes: T, N
Risk Statements: 45-23/25-50/53 
R45: May cause cancer
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: 53-45-60-61
S53: Avoid exposure - obtain special instructions before use 
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 1677 6.1/PG 2
WGK Germany: 3
RTECS: CG1100000
HazardClass: 6.1(a)
PackingGroup: II

OSHA PEL: TWA 0.01 mg(As)/m³; Cancer Hazard
ACGIH TLV: TWA 0.01 mg/m³; Confirmed Human Carcinogen; BEI: 35 μ (As)/L inorganic arsenic and methylated metabolites in urine
NIOSH REL: (Arsenic, Inorganic) CL 2 µg(As)/m³/15 M
DOT Classification:  6.1; Label: Poison

 Arsenic acid, monopotassium salt (CAS NO.7784-41-0) is high toxic. It is noncombustible and it will decomposition of toxic arsenic fumes when heating. So the storage environment should be ventilate, low-temperature and dry.