The Health and Safety Executive was accused today of condemning thousands of women to occupational cancer.
The Hazards workplace safety campaign claimed that it was ignoring women's work-related cancer and its "denial, delay and dithering" would lead to the deaths of more women, particularly from breast cancer.
About 18,000 men and women die from work-related cancer each year but action to prevent it has been sidelined in favour of yet more research, Hazards said.
It accused the HSE of adopting "old-fashioned, outdated approaches" that miss many modern workplace risks but especially ignore women's cancers.
Campaigners demonstrated outside a HSE conference on occupational diseases in London today, leaving their bras outside the British Library in protest.
Activist Hilda Palmer said: "This 'three monkeys' approach is especially deadly for work-related cancer in women, which has been completely ignored, under-researched and so much less likely to be targeted for preventative action."
And Helen Lynn of the Alliance for Cancer Prevention said such cancer is "largely preventable."
She said not trying to reduce the risk "could be viewed as an act of wilful neglect."
Campaigners said that the traditional approach of trying to limit exposure to cancer-causing chemicals is not effective.
Ms Palmer urged the HSE to "make publicly explicit" that workplace cancers could be prevented and called on the government to take action, particularly on women's cancers.
The World Health Organisation says that nearly a quarter of diseases are caused by environmental factors, including chemicals.
A HSE spokesman said it "recognises that more can be done" and the conference, to which the Hazards campaigners were invited, was trying to find new ways to fight workplace diseases.