Which asbestos-containing product was commonly used for fireproofing?

Sprayed-on asbestos insulation was commonly used for fireproofing due to its ability to provide thermal insulation and fire resistance. This material was applied to structural steel, ceilings, and walls to protect them from high temperatures and to enhance overall fire safety in buildings. Its effectiveness in controlling heat transfer made it a popular choice during construction before the awareness of the health risks associated with asbestos exposure led to widespread regulations and bans on its use.

Other materials listed, while they contain asbestos and serve specific construction purposes, do not primarily focus on the fireproofing aspect to the same degree. Asbestos cement sheets were often used for siding and roofing; floor tiles are flooring products; and gasket materials are typically used for sealing in various applications. None of these alternatives served as a fireproofing solution as effectively as sprayed-on asbestos insulation.