International Agency for Research on Cancer (IARC) - Summaries & Evaluations
DIRECT BLUE 6
VOL.: 29 (1982) (p. 311)
CAS No.: 2602-46-2
Chem. Abstr. Name: 2,7-Naphthalenedisulfonic acid,
3,3'-[(1,1'-biphenyl)-
4,4'-diylbis(azo)]bis(5-amino-4-hydroxy)-,tetrasodium salt
5. Summary of Data Reported and Evaluation
5.1 Experimental data
Oral administration to rats of one commercial sample of Direct Blue 6
resulted in hepatocellular carcinomas and neoplastic nodules in males
and females sacrificed 13 weeks after start of exposure to the highest
dose at which animals survived. Lower doses produced only liver-cell
changes such as foci of cellular alteration.
Direct Blue 6 is teratogenic in rats only when injected during the
first half of pregnancy.
No data were available to assess the mutagenicity of this compound.
5.2 Human data
Occupational exposure to Direct Blue 6 has and probably still does
occur during its production and its use for the dyeing of textiles,
leather and paper. Benzidine and its metabolic derivatives have been
detected in the urine of workers exposed to direct azo dyes.
No data were available to assess the mutagenicity or chromosomal
effects of this compound to man.
No study of exposure to Direct Blue 6 was available to the Working
Group. An epidemiological study of silk dyers and painters who had
multiple exposure to benzidine-based and other dyes indicated that
those exposures were strongly associated with the occurrence of
bladder cancer. Case reports and other epidemiological studies
support the existence of such a relationship.
5.3 Evaluation
There is sufficient evidence that commercial Direct Blue 6 is
carcinogenic to rats.
Although the epidemiological data were inadequate to evaluate the
carcinogenicity to man of Direct Blue 6 alone, they, together with the
presence of benzidine in the urine of exposed workers, provide
sufficient evidence that occupational exposure to benzidine-based dyes
represents a carcinogenic risk to man.
For definition of the italicized terms, see Preamble Evaluation.
Subsequent evaluation: Suppl. 7 (1987)
Synonyms
- Airedale Blue 2BD
- Aizen Direct Blue 2BH
- Amanil Blue 2BX
- Atlantic Blue 2B
- Atul Direct Blue 2B
- Azocard Blue 2B
- Azomine Blue 2B
- Belamine Blue 2B
- Bencidal Blue 2B
- Benzanil Blue 2B
- Benzo Blue BBA-CF
- Benzo Blue BBN-CF
- Benzo Blue GS
- Blue 2B
- Blue 2B Salt
- Brasilamina Blue 2B
- Calcomine Blue 2B
- Chloramine Blue 2B
- Chlorazol Blue B
- Chlorazol Blue BP
- Chrome Leather Blue 2B
- CI 22610
- C.I. 22610
- C.I. Direct Blue 6
- C.I. Direct Blue 6, Tetrasodium Salt
- Cresotine Blue 2B
- Diacotton Blue BB
- Diamine Blue 2B
- Diamine Blue BB
- Diaphtamine Blue BB
- Diazine Blue 2B
- Diazol Blue 2B
- Diphenyl-4,4'-bis-azo-2"-8"-amino-1"-naphthol-3",6"-disulphonatesodium
- Diphenyl Blue 2B
- Diphenyl Blue KF
- Diphenyl Blue M2B
- Direct Blue A
- Direct Blue 2B
- Direct Blue BB
- Direct Blue GS
- Direct Blue K
- Direct Blue M2B
- Direct Blue WBB
- Enianil Blue 2BN
- Fenamin Blue 2B
- Fixanol Blue 2B
- Hispamin Blue 2B
- Indigo Blue 2B
- Kayaku Direct
- Kayaku Direct Blue BB
- Mitsui Direct Blue 2BN
- Naphtamine Blue 2B
- Niagara Blue B
- Niagara Blue 2B
- Nippon Blue BB
- Paramine Blue 2B
- Phenamine Blue BB
- Pheno Blue 2B
- Pontamine Blue BB
- Tertrodirect Blue 2B
- Vondacel Blue 2B
Last updated: 9 April 1998