SYNONYMS

DEFINITION







CLASS

COLOUR INDEX NO.

EEC NUMBER

EINECS

CHEMICAL NAMES

CHEMICAL FORMULA

MOLECULAR WEIGHT

ASSAY

DESCRIPTION

IDENTIFICATION
a. Spectrometry
b. Red solution in water

PURITY
Water Insoluble matter

Subsidiary colouring matters

Unsulfonated primary aromatic amines

Ether extractable matter

Arsenic

Lead

Mercury

Cadmium

Heavy metals (as Pb)

ACID FUCHSINE * C.I. RED 33 *D & C RED 33 * ACID RED 33

The color additive D&C Red No. 33 is principally
the disodium salt of 5-amino-4-hydroxy-3-(phenylazo)-2,7-
naphthalenedisulfonic acid (CAS Reg. No. 3567-66-6). To manufacture the
additive, the product obtained from the nitrous acid diazotization of
aniline is coupled with 4-hydroxy-5-amino-2,7-naphthalenedisulfonic acid
in an alkaline aqueous medium. The color additive is isolated as the
sodium salt.

MONOAZO

17200

E-1

222-656-9

disodium 5-amino-4-hydroxy-3-(phenylazo)naphthalene-2,7-disulphonate

C16H13N3O7S2.2Na

000.00

Content not less than 82% total colouring matters,

Bluish Red powder


Maximum in water at ca 000 nm



Not more than 0.2%

Not more than 3.0%

Not more than 0.01%


Not more than 0.2% Under neutral conditions

Not more than 3 mg/kg.

Not more than 10 mg/kg.

Not more than 1 mg/kg.

Not more than 1 mg/kg.