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

a viscosity control for waterproofing since asbestos content
aids in the application of an even coat without gaps or
holes;
a sag resistance to ensure that the compound remains
stationary on steep surfaces, and does not melt and run in
the event of a fire;
a maintenance of surface protection since asbestos fiber
prevents the liquefied asphalt from penetrating the
resident surface;
a
a
a
asphalt affinity to provide uniform asbestos dispersion
without bunching or settling of fibers;
weathering resistance to retard oxidation and deterioration
of the asphalt; and,
low cost.
Companies that manufacture, roof coatings also manufacture roofing cements.
Production is typically a batch process. Bagged asbestos (usually grade 7
chrysotile) is moved from storage and dumped into a fluffing machine which is
used to separate the fibers that may have been compressed together. The
fibers are
then generally transferred to a batch mixing tank where other
ingredients are mixed until the desired consistency is obtained. Finally the
mixture is sent for packaging or containerizing, usually into tank trucks and
five gallon metal pails with sealed lids.
In both products asbestos fibers
are thought to be completely encapsulated by other product constituents (ICF
1986; Krusell and Cogley 1982).
B. Producers of Roof Coatings and Cements
In 1985, 31 firms operating 68 plants nationwide produced approximately 76
million gallons 1 of asbestos containing roof coatings and cements.
These
companies consumed 29.6 thousand tons of fiber accounting for 20.4 percent of
1 Four of the 31 companies producing asbestos containing roof coatings
and cements in 1985 refused to provide production and fiber consumption data
for their 10 plants in operation; their production volume and fiber
consumption have been estimated using the method described in Appendix A and
are included in the totals presented here.
-2?