Molecule structure of Potassium selenate (CAS NO.7790-59-2):

IUPAC Name: Dipotassium selenate 
Molecular Weight: 221.1542 g/mol
Molecular Formula: K₂O₄Se 
Density: 3.07 g/mL at 25 °C(lit.)
Sensitive: hygroscopic
Exact Mass: 221.823594
MonoIsotopic Mass: 221.823594
Topological Polar Surface Area: 80.3
Heavy Atom Count: 7 
Complexity: 62.2
Canonical SMILES: [O-][Se](=O)(=O)[O-].[K+].[K+]
InChI: InChI=1S/2K.H2O4Se/c;;1-5(2,3)4/h;;(H2,1,2,3,4)/q2*+1;/p-2
InChIKey: YAZJAPBTUDGMKO-UHFFFAOYSA-L
EINECS: 232-214-7

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

Hazard Codes: T, N
Risk Statements: 23/25-33-50/53 
R23/25:Toxic by inhalation and if swallowed. 
R33:Danger of cumulative effects. 
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 2630 6.1/PG 1
WGK Germany: 3
RTECS: VS6600000
HazardClass 6.1
PackingGroup I
Poison by intravenous route. Moderately toxic by ingestion. Experimental reproductive effects. When heated to decomposition it emits toxic fumes of Se and K₂O. See also SELENIUM COMPOUNDS.

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, Corrosive

 Potassium selenate (CAS NO.7790-59-2) is also named as NSC 378343 ; Selenic acid, dipotassium salt ; Selenic acid, potassium salt (1:2) . Potassium selenate (CAS NO.7790-59-2) is white powder. And it has weak oxidizing or reducing powers. Redox reactions can however still occur. The majority of compounds in this class are slightly soluble or insoluble in water. If soluble in water, then the solutions are usually neither strongly basic nor strongly acidic. These compounds are not water-reactive. Potassium selenate is highly toxic. If people inhaled, swallowed or absorbed through skin, it may be fatal. So prople must avoid any skin contact. The effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution. It is non-combustible, Potassium selenate itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Containers may explode when heated. Runoff may pollute waterways.