IUPAC Name: Tripotassium phosphate 
Following is the structure of Potassium phosphate, tribasic (CAS NO.7778-53-2):
            
Molecular Formula: K₃O₄P
Formula Weight: 212.27
Melting point: 1340 °C
Density : 2.564 g/mL at 25 °C(lit.)
Water Solubility : 50.8 g/100 mL (25 °C)
Boiling Point: 158 °C at 760 mmHg
Vapour Pressure: 1.41 mmHg at 25 °C
Sensitive : Hygroscopic
Merck : 14,7660
Appearance: Solid. white powder or crystal
Solubility: soluble in water. Insoluble in alcohol
Stability: stable. Incompatible with strong oxidizing agents, moisture.
Product Categories of Potassium phosphate, tribasic (CAS NO.7778-53-2): Inorganics
Canonical SMILES: [O-]P(=O)([O-])[O-].[K+].[K+].[K+]
InChI: InChI=1S/3K.H3O4P/c;;;1-5(2,3)4/h;;;(H3,1,2,3,4)/q3*+1;/p-3
InChIKey: LWIHDJKSTIGBAC-UHFFFAOYSA-K

 Potassium phosphate, tribasic (CAS NO.7778-53-2) hasn't been listed as a carcinogen by ACGIH, IARC, NTP, or CA Prop 65. And the toxicological properties have not been fully investigated. You can see actual entry in RTECS for complete information.

Reported in EPA TSCA Inventory.

Hazard Codes: C,Xi
Risk Statements: 38-41-34 
R38:Irritating to skin. 
R41:Risk of serious damage to the eyes. 
R34:Causes burns.
Safety Statements: 26-39-45-36/37/39 
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S39:Wear eye / face protection. 
S45:In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) 
S36/37/39:Wear suitable protective clothing, gloves and eye/face protection.
RIDADR: UN 1805 8/PG 3
WGK Germany: 2
RTECS: TC8450000
F: 8-10

 Potassium phosphate, tribasic , its cas register number is 7778-53-2. It also can be called CCRIS 7321 ; Phosphoric acid, tripotassium salt ; Potassium orthophosphate ; Potassium phosphate ; Potassium phosphate (K3PO4) ; Potassium phosphate, tribasic ; Tripotassium phosphate ; and UNII-16D59922JU .
 Potassium phosphate, tribasic (CAS NO.7778-53-2) could be stable under normal temperatures and pressures. It absorbs moisture or water from the air. It should avoid the condition like incompatible materials, exposure to moist air or water. It is not compatible with strong oxidizing agents. However, its hazardous polymerization will not occur. In addition, be sure that Potassium phosphate, tribasic (CAS NO.7778-53-2) is not necessary to strain to reach materials, and that shelves are not overloaded. Use shelves or cabinets sturdy enough to bear the weight of the chemicals.