Two suits were filed on Tuesday in U.S. District Court in Missoula, Montana, seeking class-action status and asking for punitive damages. The first suit accuses Columbia, Maryland-based Grace of knowing that by 1968, its plant was dispersing asbestos-containing dust into the air in the Libby community. It contends that a 1969 Grace in-house study revealed a lung disease rate of 92 percent in Libby workers who worked more than 20 years at the mine. Grace did not disclose the study to the public or the medical community. The suit accuses Grace of intentionally misrepresenting to doctors and workers that asbestos had not been associated with mesothelioma, a fatal form of cancer, and of concealing an internal study demonstrating an association between asbestos and mesothelioma. Grace said it believed Zonolite was safe.

One of the Montana suits seeks payment to restore properties allegedly contaminated with asbestos that the suit came from the Libby mines, while the other seeks long-term medical diagnostic care for those exposed to asbestos.

The third suit, which also is a class action, accuses the company of fraud, deception and enriching itself at the expense of homeowners by failing to warn that the popular insulation product Zonolite contained asbestos. The third suit was filed in Boston, and seeks punitive and compensatory damages and demands that Grace pay for the removal of the insulation from homes.