Transite

Transite originated as a brand that Johns Manville, an American company, created in 1929 for a line of asbestos-cement products, including boards and pipes.

It was replaced by crystalline silica, which the International Agency for Research on Cancer has classified as being carcinogenic to humans (Class 1).

[3] Originally, transite had between 12-50% of asbestos fiber added to a cement base to provide tensile strength (similar to the rebar in reinforced concrete), and other materials.

[4] It was frequently used for such purposes as furnace flues, roof shingles, siding, soffit and fascia panels, and wallboard for areas where fire retardancy is particularly important.

Because cutting, breaking, and machining asbestos-containing transite releases carcinogenic asbestos fibers into the air, its use has fallen out of favor.