Spray polyurethane foam (SPF) roof systems are unique and expose
SPF applicators to a variety of dangers during the SPF application
process, as well as some that are confronted by all roofing
workers. If SPF applicators follow precautionary work practices,
the hazards of SPF roof system applications can be reduced or
A dual-component formulation is the basis for SPF roof systems.
One part is an isocyanate, and the other part is a polyol resin.
The components are transferred from their individual containers
into a proportioning unit that pumps proper amounts of each through
a hose to a spray gun where they are mixed and applied to a
Components used in SPF roofing applications and certain top-coat
products usually are characterized by the U.S. Department of
Transportation as Class 3 hazardous materials because of their
flammable and toxic natures. Breathing isocyanate vapors,
especially when concentrations are increased during spray
applications, can cause the...
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