The European Commission announced Thursday a ban on 22 chemicals used in hair dyes, following a study linking long-term use to a risk of bladder cancer.

But the European Union's executive arm underlined that the chemicals were not commonly used in hair dyes available on the European market.

The substances involved have been banned because the industry has failed to provide evidence that they are safe, and is part of a plan to establish a list of hair dye ingredients "which are considered safe for human health," it said.

"Substances for which there is no proof that they are safe will disappear from the market," said EU commission Vice-President Guenter Verheugen, responsible for enterprise and industry policy.

According to the EUs Scientific Committee on Consumer Products (SCCP), there is evidence "that the regular and long term use of hair dyes by women may be associated with the development of bladder cancer," said the commission.

The number of consumers potentially involved is huge: more than 60 percent of women and between five and 10 percent of men colour their hair an average of six to eight times a year, according to EU data.

"Our high safety standards not only protect EU consumers, they also give legal certainty to European cosmetics industry," said Verheugen.

The hair dye market in the 25-nation European bloc was worth 2.6 billion euros (3.3 billion dollars) in 2004, which accounts for some eight percent of the value of output of the cosmetics industry in Europe. Permanent hair dyes account for 70-80 of the colouring product market in Europe.

The ban announced Thursday will enter into force on 1 December 2006.