Asbestos Mattress (Sectional Pipe Insulation)

Asbestos mattress, also known as sectional pipe insulation or asbestos quilted mattress, is a pre-formed insulation product designed to wrap around large-diameter pipes, boilers, tanks, and industrial vessels. The mattress consists of a core of asbestos fibres, typically amosite or chrysotile, stitched or wired between layers of asbestos cloth, wire mesh, or canvas. Asbestos content ranges from 50 % to over 90 % depending on the formulation.

These mattresses were manufactured in sections shaped to fit specific pipe diameters and equipment profiles. They were secured in place using wire ties, metal bands, or stitching, and were designed to be removable for equipment maintenance and then reinstalled. This removability was a key selling point for industrial facilities that needed periodic access to equipment.

Asbestos mattresses were heavily used from the 1930s through the late 1970s in power stations, oil refineries, chemical processing plants, marine vessels, and large commercial heating systems. They were the insulation of choice for high-temperature applications where pre-formed rigid sections would not fit irregular shapes.

The risk level is maximum (Risk Level 5) because the material is highly friable and frequently disturbed. The repeated removal and reinstallation cycles during equipment maintenance caused extensive fibre release. Even when left in place, thermal cycling and vibration from adjacent machinery causes progressive degradation, and the asbestos fill migrates through the outer fabric, creating visible fibre deposits on surfaces.

Laggers and insulation workers who handled asbestos mattresses suffered some of the highest mesothelioma rates of any occupational group. Modern removal requires full enclosure conditions with negative pressure, personal air monitoring for each worker, and decontamination procedures upon exiting the work area. Replacement insulation mattresses are now manufactured from mineral wool, ceramic fibre, or silica aerogel.