WEDNESDAY April 2, 2008 (foodconsumer.org) -- Using hair dyes may increase risk for bladder cancer, a review study suggests.

After reviewing evidence, a panel of the International Agency for Research on Cancer in Lyon, France found a small but consistent risk of bladder cancer in male hairdressers and barbers.

The increased risk of bladder cancer could be extended to personal use of hair dyes, says The Independent.

A second review on personal use of hair dyes found evidence suggesting a possible association with lymphoma and leukemia in addition to bladder cancer.

But the panel found the evidence on the link was inadequate and concluded that personal use of hair dyes was "not classifiable as to its carcinogenicity to humans".

The panel of 17 scientists met last February to consider the latest evidence and update advice last issued by the agency in 1993, according to The Independent, a UK newspaper.

Dark hair dyes tend to contain the highest level of the toxic colorants some of which had been discontinued because of the cancer link in rats.

Dr Robert Baan of the IARC and team were quoted as saying in The Lancet Oncology "Because of few supporting findings by duration or period of exposure, the working group considered these data as limited evidence of carcinogenicity and reaffirmed occupational exposures of hairdressers and barbers as 'probably carcinogenic to humans'."