For almost a century, fire curtains were made from the naturally occurring mineral called asbestos. The fibers of asbestos made curtains withstand flames and prevent major catastrophes. Unfortunately, they posed another kind of threat.
In time, the fire curtains would start to deteriorate and the workers would have been unknowingly exposed to asbestos fibers by simply lowering them on stage. Any disturbance to a used up or deteriorated asbestos fire curtain would cause it to shred, making the toxic particles airborne. You could have been exposed if: