Asbestos canvas was a textile material obtained from asbestos cloth. It was used mainly for insulating steam pipes and machinery like boilers. There were even cases of asbestos canvas being used as fire curtains in places like movie theaters.
In spite of all the properties asbestos brought to insulation products, with the passing of time, asbestos would become friable, placing its fibers in an unstable state. This was also the main danger concerning asbestos canvas, as it could have turned friable when it got worn out. You could have been exposed if: