After World War II there was a huge housing and industry boom. This made the demand for products that contained asbestos to grow as fast as the demand for homes and commercial buildings. Eventually there were thousands of different materials and products in existence that contained the deadly asbestos.
Because it could insulate so efficiently and it was durable, asbestos was commonly used in factories and other industries. They required insulation to protect the workers from heat as well as manage the temperatures in machine rooms where large machines that put out a lot of heat were used. Asbestos-containing machine room ceiling tiles were installed in order to insulate these rooms against the heat put out by these machines.
Asbestos was used because it cheap, lightweight, and a good insulator. The fact that it was toxic was either not known or ignored by some employers. By 1970 thousands of workers had already developed fatal diseases attributed to asbestos exposure from machine room tiles in the ceiling.