Insulating Block by Combustion Engineering

Product Description

Combustion Engineering produced insulating block as part of its broader line of industrial thermal insulation materials between 1964 and 1972. The company, which operated as a major industrial equipment and engineering conglomerate throughout much of the twentieth century, supplied insulating block to industrial facilities where high-temperature process equipment required durable, long-lasting thermal protection.

Insulating block was a rigid, pre-formed insulation product designed to be applied to boilers, furnaces, kilns, pressure vessels, and other high-heat industrial equipment. Unlike flexible blanket or wrap-style insulation, block insulation was manufactured in solid, cut-to-size shapes that could be fitted around equipment surfaces, secured in place, and finished with a protective outer layer. This rigid format made it particularly well-suited for stationary industrial installations where precise insulation coverage was required to maintain operating temperatures, reduce heat loss, and protect surrounding structures and workers from radiant heat.

Combustion Engineering was a recognized name in the industrial power and process industries. The company supplied equipment and materials to power generation plants, petrochemical refineries, steel mills, and other heavy industrial operations across the United States. Its insulating block was distributed and installed during the period when asbestos-containing insulation remained standard practice in these sectors, well before federal regulatory agencies moved to restrict or ban such materials.

Asbestos Content

Combustion Engineering’s insulating block manufactured between 1964 and 1972 contained chrysotile asbestos as a primary component of its formulation. Chrysotile, commonly referred to as white asbestos, is a serpentine-form fiber that was extensively used in rigid and semi-rigid insulation products throughout the mid-twentieth century because of its heat resistance, structural binding properties, and relative availability as a raw material.

In rigid insulating block, chrysotile fibers were typically combined with other binding and filler materials to form a cohesive, load-bearing insulation matrix capable of withstanding sustained exposure to high operating temperatures. The asbestos content in products of this type served multiple functions: it reinforced the structural integrity of the block, contributed to thermal stability, and helped the product maintain its shape and insulating efficiency under thermal cycling — the repeated heating and cooling that industrial equipment undergoes during normal operation.

Federal regulatory frameworks developed after the period of manufacture have since recognized chrysotile asbestos as a human carcinogen at any level of exposure. The Environmental Protection Agency’s Asbestos Hazard Emergency Response Act (AHERA) and OSHA’s asbestos standards both address the risks posed by chrysotile-containing materials, including thermal insulation products of the type manufactured by Combustion Engineering during this period.

How Workers Were Exposed

Industrial workers who handled, installed, maintained, repaired, or removed Combustion Engineering insulating block during and after the period of manufacture faced potential asbestos fiber exposure through several documented pathways.

During installation, workers were required to cut, shape, and fit insulating block to equipment contours. Sawing, grinding, or chiseling rigid asbestos-containing block generates fine particulate dust that carries airborne asbestos fibers into the breathing zone of workers performing these tasks. In enclosed industrial settings — boiler rooms, turbine halls, refinery processing units — ventilation was often limited, and dust generated during insulation work could remain suspended in the air for extended periods.

Maintenance and repair work represented a significant secondary exposure pathway. Industrial equipment requires periodic inspection, and insulation is frequently disturbed, removed, or replaced during these activities. Workers who removed sections of installed insulating block encountered materials that had often become brittle and friable over years of thermal cycling, making fiber release during disturbance more likely than during initial installation. The act of breaking apart aged block insulation can release concentrated bursts of asbestos fibers.

Bystander or co-worker exposure was also a recognized risk in industrial environments. Workers performing tasks in the same area as insulation installation or removal — even if not directly handling the product themselves — could inhale fibers that had become airborne through the work of nearby colleagues. Industrial facilities during this era often had multiple trades and worker categories operating in close proximity, and the practice of erecting containment barriers around asbestos work was not standard until regulatory requirements were established in later decades.

The latency period for asbestos-related disease — the interval between first exposure and clinical diagnosis — typically spans decades, meaning workers exposed during the 1964–1972 production period or in subsequent years during maintenance activities may only be receiving diagnoses today. Diseases documented in connection with occupational asbestos exposure include mesothelioma, asbestosis, lung cancer, and other pulmonary conditions.