Molecular Formula: C₂₈H₁₄N₂O₄
Molecular Weight: 442.43 g/mol
Canonical SMILES: c12c3c([nH]c4c5c(c(c6ccccc6c5=O)=O)ccc4[nH]3)ccc1c(c1ccccc1c2=O)=O
InChI: InChI=1/C28H14N2O4/c31-25-13-5-1-3-7-15(13)27(33)21-17(25)9-11-19-23(21)29-20-12-10-18-22(24(20)30-19)28(34)16-8-4-2-6-14(16)26(18)32/h1-12,29-30H
EINECS: 201-375-5
Stability: Incompatible with strong oxidizing agents.
XLogP3-AA: 4.9  
H-Bond Donor: 2  
H-Bond Acceptor: 6
Density: 1.487 g/cm³ 
Flash Point: 253.9 °C 
Enthalpy of Vaporization: 107.96 kJ/mol 
Boiling Point: 740.2 °C at 760 mmHg 
Melting Point: 470-500 °C
Water solubility: <0.1 g/100 mL at 21 °C
Vapour Pressure of Vat Blue 4 (CAS NO.81-77-6): 8.92E-22 mmHg at 25 °C

 Vat Blue 4 (CAS NO.81-77-6) was patented in 1901 by Rene Bohn as the first anthraquinone vat dye, one of the dyes with very good fastness to light and washing.

  Vat Blue 4 (CAS NO.81-77-6) is used to dye unmordanted cotton and as a pigment in quality paints and enamels.

 Vat Blue 4 is Reported in EPA TSCA Inventory.

Poison by intratracheal route. When heated to decomposition it emits toxic vapors of NO_x.
Risk Statements: 20/21/22 
R20/21/22: Harmful by inhalation, in contact with skin and if swallowed.
Safety Statements: 22-36/37/39 
S22: Do not breathe dust. 
S36/37/39: Wear suitable protective clothing, gloves and eye/face protection.
RTECS of Vat Blue 4 (CAS NO.81-77-6): CB8761100

  Vat Blue 4 (CAS NO.81-77-6), its Synonyms are Indanthrene ; 5,9,14,18-Anthrazinetetrone, 6,15-dihydro- ; 6,15-Dihydro-5,9,14,18-anthrazinetetrone ; C.I. Pigment Blue 60 ; Anthraquinone Blue ; Anthraquinone Deep Blue ; Blue anthraquinone pigment ; Indanthren Blue ; Indanthrene blue RS . It is blue needles with a metallic lustre.