The conclusion was reached by a panel of scientists, at the International Agency for Research on Cancer (IRAC) in Lyon, who were brought together last February to review the evidence on the cancer link that has built up over the past 15 years, according to press reports. Professionals and personal users In the report published in The Lancet Oncology Dr Robert Baan said: "A small but consistent risk of bladder cancer was reported in male hairdressers and barbers." While the panel was agreed that regular occupational exposure to hair dye increased cancer risk they found data on personal use inconclusive. The evidence was adjudged to be insufficient to make a definitive conclusion on the carcinogenicity of hair dye when exposure is limited to personal use. Concerns about specific chemicals The scientists also reviewed the data related to the cancer causing potential of aromatic amines and organic dyes and added the following chemicals to its list of probable and definite carcinogens.
4-Chloro-ortho-toluidine, probably carcinogenic
Benzidine-based dyes, carcinogenic
The report will soon be published as Volume 99 of the monographs of the IARC, which is an arm of The World Health Organisation (WHO). The publication of the findings comes on the back of a mounting body of studies including a recent report by UK consumer magazine Which?. The magazine found that several highly allergenic and potentially carcinogenic chemicals were still widely used in hair dyes without being properly labelled. Which? conceded that the vast majority of hair dye users continue to use such products without suffering adverse reactions. It added that the lack of acceptable alternatives also stood in the way of the removal of potentially hazardous ingredients.