Gaskets are materials used to seal one compartment of a device ...

$20.5 million in 1985, based on an average price of $5.69 per square yard (ICF
l986a).
C. Trends
Between 1981 and 1985,
two manufacturers of compressed asbestos sheet
gasketing, Jenkins Brothers (Bridgeport, CT) and Manville Sales Corporation
(Manville, NJ and Waukegan, IL) discontinued their operations. During those
four years, total production fell 44 percent from 6,472,879 square yards to
3,607,408 square yards (see Table 2). Currently, non-asbestos gaskets hold
less than 50 percent of the gasket market, but as concerns about asbestos and
its health effects grow, the use of asbestos in compressed sheet gaskets is
expected to decline (ICF l986a).
D. Substitutes
Asbestos has been used in sheet gaskets because it is chemically inert,
nearly indestructible and can be processed into fiber. Asbestos fibers
partially adsorb the binder with which they are mixed during processing;
they
then intertwine within it and become the strengthening matrix of the product.
Since the product contains as much as 80 percent asbestos fiber, manufacturers
are also employing it as a filler. The balance of the product is the binder
which holds the asbestos in the matrix (Kirk-Othmer 1981).
A single substitute for asbestos is not available. Manufacturers have,
therefore, been forced to replace the asbestos fiber with a combination of
substitute materials. The formulations of the substitute products most often
include a combination of more than one type of substitute fiber and more than
one filler in order to reproduce the properties of asbestos necessary for that
application. Formulation of substitute products is done on an
application-by-application basis by each manufacturer (ICF 1986a). For the
purposes of this analysis, the substitute products will be grouped into six
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