Mining and Mills Occupational Health Programs
In 1913, a large vermiculite deposit was discovered in Libby, Montana. Commercial
vermiculite mining began a decade later by the Zonolite Company.
Grace purchased the Zonolite Company in 1963 and operated the Libby vermiculite mine
and processing mill until 1990. The company employed up to 200 people annually at
the mine and mill.
Libby vermiculite was used in a variety of applications after it was processed. The
vermiculite mined near Libby contained a naturally occurring impurity, a form of
asbestos frequently referred to as tremolite. It was largely removed during the
processing of crude vermiculite ore.
During the years it operated the mine and in the years since, Grace consistently
improved its occupational health programs in step with the growing body of information
on the health hazards associated with asbestos. The company also spent a great deal
of time and money improving its operations to reduce the amount of asbestos and
dust its employees were exposed to.
- Grace started an annual X-ray program in 1964 to give employees the ability to track
their health from year to year, adding lung function tests in 1974. Each year, the
results were forwarded to employees' personal physicians.
- Grace required employees to wear respirators in most locations in the mill and,
in 1978, banned smoking on the premises. Smoking increases the risk of contracting
certain asbestos-related diseases.
- In the mid-1970s, Grace installed signs in areas of the mine and mill that warned
of asbestos in the dust. And in 1979, Grace began an extensive training program
that relied on the best available data on the health hazards associated with asbestos.
- At the Libby facility and elsewhere, the company complied with state and federal
workplace regulations concerning asbestos even as they changed in step with the
growing body of knowledge about asbestos.
- Grace actively worked to limit employees' exposure to dust in the mill operations,
including the installation of new air filtering and dust control equipment in 1966,
1968, 1969, 1970, 1974 and 1976.
- In 1974, Grace shifted operations to a wet mill that reduced airborne asbestos dust
to levels set by government agencies. The mill, specifically designed to meet the
needs of the Libby operation, cost approximately $14 million to build. Grace paid
$9.6 million for the Zonolite Company in 1963.
- State and federal regulators recognized Grace's success in reducing airborne asbestos
at the time. In 2001, a report by the U.S. Mine Safety and Health Administration's
Inspector General said Grace's Libby operation was regularly inspected and that
it was consistently in compliance with exposure guidelines applicable at that time.
- In 1985, Grace released publicly a study by McGill University that showed people
who worked in the mine and mill during the 1950s and 1960s were developing lung
impairments at a higher rate than the general public and predicted an even higher
rate of lung impairment and cancers for that group of employees.
- The progression of asbestos knowledge is particularly evident in the way the U.S.
Occupational Safety and Health Administration mandated permissible exposure limits
(PELs). Between 1971 and 1994, OSHA reduced permissible exposure limits four times,
from 12 asbestos fibers/cc in 1971 to 0.1 fibers/cc in 1994.
