METHYL ORANGE

PRODUCT IDENTIFICATION

 

CAS NO. 502-02-3 (Base)
547-58-0 (Sodium)

METHYL ORANGE 

EINECS NO. 208-925-3
FORMULA (CH3)2NC6H4N=NC6H4SO3Na
MOL WT. 327.33
H.S. CODE 3204.12.5090
TOXICITY  
SYNONYMS C.I. Acid Orange 52; C.I. 13025;
Sodium 4-(4-dimethylaminophenylazo)benzenesulphonate; Methyl Orange; Tropaeolin D; p-((p-(Dimethylamino)phenyl)azo)benzenesulfonic acid sodium salt; Sodium 4-(Dimethylamino)azobenzene-4'-sulfonate; Sodium p-dimethylaminoazobenzenesulfonate; Orange 3; Orange III; Methyl Orange B; 4-Dimethylaminoazobenzene-4'-sulphonic acid sodium salt; Helianthin; Other CAS RN 1342-24-1; 66777-17-1;
SMILES

c1(ccc(cc1)S(=O)(=O)[O-])/N=N/c1ccc(cc1)N(C)C.[Na+]

CLASSIFICATION

Acid Dye, Stain,

EXTRA NOTES

 

PHYSICAL AND CHEMICAL PROPERTIES

PHYSICAL STATE orange fine crystalline powder
MELTING POINT 300 C
BOILING POINT  
SPECIFIC GRAVITY  
SOLUBILITY IN WATER Soluble in hot water (Insoluble in alcohol)
SOLUBILITY

 

AUTOIGNITION  
pH  
VAPOR DENSITY  
NFPA RATINGS Health hazard: 2, Fire: 0, Reactivity Hazard: 0

REFRACTIVE INDEX

 
FLASH POINT

 

STABILITY Stable under ordinary conditions

EXTERNAL LINKS & GENERAL DESCRIPTION

Wikipedia Linking - Methyl Orange

Google Scholar Search - Methyl Orange

Drug Information Portal (U.S. National Library of Medicine) - Methyl Orange

PubChem Compound Summary - Methyl Orange

KEGG (Kyoto Encyclopedia of Genes and Genomes) - Methyl Orange

http://www.ebi.ac.uk/ - Methyl Orange

http://www.ncbi.nlm.nih.gov/ - Methyl Orange

http://toxnet.nlm.nih.gov/
Hazardous Substances Data Bank - Methyl Orange

Local:
Acid dyes are water-soluble dyes employed mostly in the form of sodium salts of the sulfonic or carboxylic acids. They are anionic which attach strongly to cationic groups in the fibre directly. They can be applicable to all kind of natural fibres like wool, cotton and silk as well as to synthetics like polyesters, acrylic and rayon. But they are not substantive to cellulosic fibres. They are also used in paints, inks, plastics and leather. Orange acid azo dyes produce an orange-pink color. They are used in coloring foods and drugs and as intermediates for making photosensive dyes and drugs. They are used  as counter stains in histology and cytology and as components of Mallory's acid fuchsin. Methyl Orange (acid magenta) is a various mixture of sulfonated fuchsins. There are four of these compounds which have three sulfonic groups each. It is used in Andrade's indicator and in various complex stains to demonstrate collagen fibres red and in smooth muscle in contrast to collagen. It is used as a pH indicator. The pH range of Methyl Orange id form pH 3.0 pink-red to pH 4.4 yellow. Methyl Orange is used in oil field industry for alkalinity test of mud filtrate.

Examples of orange acid dyes

  • Ethyl orange Sodium salt ( CAS RN: 62758-12-7)
  • Orange II ( CAS RN: 633-96-5)
  • Orange III (methyl orange, CAS RN: 547-58-0)
  • Orange IV  (CAS RN: 554-73-4)
  • Orange G ( CAS RN: 1936-15-8)
  • Tropaeolin O (CAS RN: 547-57-9)
  • Victoria orange
  • Acid Orange II (Dibromofluorescein, 596-03-2)
SALES SPECIFICATION

APPEARANCE

orange fine crystalline powder
DYE CONTENT

95.0% min

LOSS ON DRYING

5.0% max

ABSORPTIVITY (pH 3.0)501-504nm: 1050 - 1150
(pH 4.4)467-471nm: 750 - 850
TRANSPORTATION
PACKING  
HAZARD CLASS 6.1 (Packing Group: III)
UN NO. 3143
SAFETY INFORMATION

HAZARD OVERVIEW

Toxic by ingestion

GHS

 

SIGNAL WORD Warning

PICTOGRAMS

HAZARD STATEMENTS

H301

P STATEMENTS

P301 + H310

EC DIRECTIVES

 

HAZARD CODES

RISK PHRASES

25

SAFETY PHRASES

46

BIOLOGICAL STAINS, INDICATORS