SYNONYMS	CHOCOLATE BROWN * C. I. FOOD BROWN 3 * FOOD BROWN 2* BROWN HT
DEFINITION	Chocolate Brown consists essentially of disodium 4,4'-(2,4-dihydroxy-5-hydroxymethyl-1,3-phenylene bisazo) di (naphthalene-l-sulfonate) and  subsidiary colouring matters together with sodium chloride and/or sulfate as the principal uncoloured components.
	Chocolate Brown  is described as the sodium salt. The calcium and the potassium salt are also permitted.
CLASS	Bisazo
COLOUR INDEX NO.	20285
EEC NUMBER	E-155
EINECS	224-924-0
CHEMICAL NAMES	Disodium 4,4'-(2,4-dihydroxy-5-hydroxymethyl-1,3-phenylene bisazo) di (naphthalene-l-sulfonate)
CHEMICAL FORMULA	C17H18N4Na2O9S2
MOLECULAR WEIGHT	652.57
ASSAY	Content not less than 70% total colouring matters, calculated as the sodium salt;
	E 1% 1cm 403 at ca 460 nm in aqueous solution at pH7
DESCRIPTION	Reddish-brown powder
IDENTIFICATION
a. Spectrometry	Maximum in water of pH 7 at ca 460 nm
b. Brown solution in water
PURITY	Not more than 0.2%
Water Insoluble matter
Subsidiary colouring matters	Not more than 10% (TLC method)
Organic compounds other than colouring matters	[4-aminonaphthalene-l-sulfonic acid] - Not more than 0.7%
Unsulfonated primary aromatic amines	Not more than 0.01% (Calculated as aniline)
Ether extractable matter	Not more than 0.2% in a solution of  pH7
Arsenic	Not more than 3 mg/kg.
Lead	Not more than 10 mg/kg.
Mercury	Not more than 1 mg/kg.
Cadmium	Not more than 1 mg/kg.
Heavy metals (as Pb)	Not more than 40 mg/kg.