A worker in a chemical dye manufacturing facility develops urothelial cell bladder cancer. This facility likely produces which of the following colors/dyes?
A. Basic Magenta. Basic Magenta (CAS: 632-99-5, IUPAC – 4-[(4-aminophenyl)-(4-imino-3-methylcyclohexa-2,5-dien-1-ylidene)methyl]aniline;hydrochloride) is a component of Magenta dye. Production of Magenta may involve exposure to aniline, auramine, orhto- and para- toluidine, benzidine, naphthylamine, and (historically) arsenic acid. Magenta production is classified by the International Agency for Research on Cancer (IARC) as carcinogenic to humans (group 1). The production process is associated with cancers of the urinary bladder. Due to co-exposures during production, conclusions regarding the carcinogenicity of the dye itself are difficult. As of Oct 2022, other dyes or dye production classified as IARC group 1 include dyes metabolized to benzidine and the production of auramine. Since Magenta is the only available answer choice with reports of cancers in humans, it is the best answer among the options. Additionally, in the small amount of data available to the IARC workgroup regarding the other compounds cancers were in sites not involving the urinary bladder. The other answer choices are classified as IARC group 3 (not classifiable as to its carcinogenicity to humans), and there are no specific IARC monographs available for the production processes of these dyes. Leukogentian Violet (B) did not have available studies for carcinogenicity in animals or humans. Evans Blue (C) produced reticuloendothelial liver sarcomas in one rat study. Malachite Green (D) was associated with benign follicular cell adenoma/carcinoma of the thyroid in female rats. Sudan Red (E) in limited rat studies has not demonstrated a specific association with cancer.
International Agency for Research on Cancer. Chemical Agents and Related Occupations: IARC Monographs on the Evaluation of Carcinogenic Risks to Humans Volume 100F. IARC Publications. 2012. ISBN 978-92-832-0138-0. Accessed 2022 Oct 18 at https://publications.iarc.fr/123. International Agency for Research on Cancer. Gentian Violet, Leucogentian Violet, Malachite Green, Leucomalachite Green, and CI Direct Blue 218: IARC Monographs on the Identification of Carcinogenic Hazards to Humans Volume 129. IARC Publications. 1975. ISBN 978-92-832-0196-0. Accessed 2022 Oct 18 at https://publications.iarc.fr/603. International Agency for Research on Cancer. Some Aromatic Azo Compounds: IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man Volume 8. IARC Publications. 1975. ISBN 978-92-832-1208-9. Accessed 2022 Oct 18 at https://publications.iarc.fr/26
Contributed by: HoanVu Nguyen