CONGO RED

PRODUCT IDENTIFICATION

 

3.0 -   5.2

 
CAS NO. 573-58-0

CONGO RED

EINECS NO. 209-358-4
FORMULA C32H22N6Na2O6S2
MOL WT. 696.66
H.S. CODE  
DERIVATION

 

TOXICITY  
SYNONYMS C.I. Direct Red 28; C.I. 22120; Direct Red C; Direct Red R;
Sodium diphenyldiazo-bis(alpha-naphthylaminesulfonate); Direct Red Y; Natrium-salz der diphenyl-bis-azo-bis-naphthylamin-4-sulfonsaeure; Congo Red 4B; Cosmos Red; Cotton Red B;  3,3'-(4,4'-Biphenylenebis(azo))bis(4-amino-1-naphthalenesulfonic acid) disodium salt; Cotton Red C; Disodium 3,3'-((1,1'-biphenyl)-4,4'-diylbis(azo))bis(4-aminonaphthalene-1-sulphonate); Other CAS RN: 550-08-3; 70248-72-5; 87440-95-7;

CLASSIFICATION

DYES / STAINS / INDICATOR /

PHYSICAL AND CHEMICAL PROPERTIES
PHYSICAL STATE red to brown powder
MELTING POINT > 360 C
BOILING POINT  
SPECIFIC GRAVITY  
SOLUBILITY IN WATER soluble
SOLUBILITY soluble in alcohol
AUTOIGNITION  
pH  
VAPOR DENSITY  
NFPA RATINGS  

REFRACTIVE INDEX

  
FLASH POINT

 

STABILITY Stable under ordinary conditions

APPLICATIONS
Congo red is a diazo dye structurally. It is a red to brown powder. The chemical name is sodium diphenyldiazo-bis(alpha-naphthylaminesulfonate). It is soluble in water and ethanol. It is red in alkaline solution and blue in acid solution. Its use in cellulose fibres are banned due to toxicity. It is used as a biological stain and as an acid-base indicator from pH range of 3.0 (blue-violet) to 5.2 (red). The color change is inverse to litmus. It is used as a diagnostic test in amyloidosis; 30% disappears within 1 hour in normal individuals, but 40 -100% disappears in amyloidosis.It was used as an antihemolytic and detoxicant.
SALES SPECIFICATION

APPEARANCE

 red to dark brown powder
TRANSITION pPH RANGE

3.0 (blue)
5.2 (red).

TRANSPORTATION
PACKING  
HAZARD CLASS  
UN NO.

 

OTHER INFORMATION
Hazard Symbols: T Risk Phrases: 45-63, Safety Phrases: 53-45