Molecular formula: Na₂Cr₂O₇
Molar mass: 261.97 g/mol
Density 2.52 g/cm³
Melting point: 356.7 °C
Appearance: A red or red-orange crystalline solid
Structure of Sodium dichromate (CAS NO.10588-01-9):
                     
IUPAC Name: Disodium oxido-(oxido(dioxo)chromio)oxy-dioxochromium
Product Category of Sodium dichromate (CAS NO.10588-01-9): Inorganics

 Sodium dichromate (CAS NO.10588-01-9) is used as the starting material for producing the solutions of chromium salts employed in chrome leather tanning and in chrome mordant dyeing of wool cloth. Pigments, such as yellow lead chromate, are manufactured from sodium dichromate , as also green chromium oxides for ceramic pigments.

 Sodium dichromate (CAS NO.10588-01-9) is manufactured from chromite, a chromium iron oxide containing approximately 50% chromic oxide (Cr₂O₃) with iron oxide (FeO), alumina (Al₂O₃), silica (SiO₂), and magnesium oxide (MgO). In the process (Fig. 1), the ore is ground and mixed with ground limestone and soda ash, and roasted at approximately 1200 °C in an oxidizing atmosphere. The sintered mass is crushed and leached with hot water to separate the soluble sodium chromate. The solution is treated with sulfuric acid to convert the sodium chromate to sodium dichromate plus sodium sulfate. Some of the sodium sulfate crystallizes in the anhydrous state from the hot solution during acidification as well as in the evaporators during concentration of the dichromate solution. From the evaporator, the hot, saturated dichromate solution is fed to the crystallizer, and then to the centrifuge and dryer.

Confirmed carcinogen with experimental tumorigenic data. Poison by ingestion, skin contact, intravenous, intraperitoneal, and subcutaneous routes. Human systemic effects by ingestion: cough, nausea or vomiting, and sweating. Human mutation data reported. A caustic and irritant. A powerful oxidizer. Potentially explosive reaction with acetic anhydride, ethanol + sulfuric acid + heat, hydrazine. Violent reaction or ignition with boron + silicon (pyrotechnic), organic residues + sulfuric acid, 2-propanol + sulfuric acid, sulfuric acid + trinitrotoluene. Incompatible with hydroxylamine. When heated to decomposition it emits toxic fumes of Na₂O. See also CHROMIUM COMPOUNDS.
Hazard Codes: T+ ,N,O
Risk Statements: 45-46-60-61-8-21-25-26-34-42/43-48/23-50/53 
R45:May cause cancer. 
R46:May cause heritable genetic damage. 
R60:May impair fertility. 
R61:May cause harm to the unborn child. 
R8 :Contact with combustible material may cause fire. 
R21:Harmful in contact with skin. 
R25 :Toxic if swallowed. 
R26:Very toxic by inhalation. 
R34:Causes burns. 
R42/43:May cause sensitization by inhalation and skin contact. 
R48:Danger of serious damage to health by prolonged exposure. 
R50/53:Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment.
Safety Statements: 53-45-60-61 
S45:In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) 
S53:Avoid exposure - obtain special instructions before use. 
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.

OSHA PEL: CL 0.1 mg/(CrO₃)/m³
ACGIH TLV: TWA 0.05 mg(Cr)/m³; Confirmed Human Carcinogen
NIOSH REL: (chromium(VI)): TWA 0.001 mg(Cr)/m³

For occupational chemical analysis use NIOSH: Chromium Hexavalent, 7024.

 Sodium dichromate , its cas register number is 10588-01-9. It also can be called Sodium bichromate ; and Chromic acid (Na₂Cr₂O₇), disodium salt .