Environmentalists filed suit yesterday to force the government to order special controls on the use of eight air pollutants that are known or suspected cancer-causing agents.

The Natural Resources Defense Council asked a U.S. district court in New York City to place the Environmental Protection Agency on a schedule for completing implementation of the controls. The EPA already has labeled the substances -- the chemicals acrylonitrile, butadiene, carbon tetrachloride, chloroform, ethylene dichloride and ethylene oxide, and the metals cadmium and chromium -- as carcinogens or suspected carcinogens.

"Under the Clean Air Act, these findings require EPA to place the compounds on the government's official list of 'hazardous air pollutants,' " said David Doniger, senior lawyer for the group. "EPA must then issue emission standards to protect the public health with an ample margin of safety within one year."

The council complained that the EPA has violated the law by announcing that it intends to curb emissions of seven of the substances, but not explaining how or when.

"It's as though the Fire Department came to your burning house and said, 'We intend to put it out,' " Doniger said.

The EPA has dealt with the eighth substance on the council's list -- acrylonitrile -- by saying the states will be responsible for controls.