Pabco Super Caltemp Pipe Covering and Block Insulation

Manufacturer: Fibreboard-Pabco Years Produced: 1952–1972 Asbestos Type: Chrysotile

Product Description

Pabco Super Caltemp was a line of thermal insulation products manufactured by Fibreboard-Pabco during the mid-twentieth century. The product line included two primary forms: pipe covering, designed to wrap and insulate industrial piping systems, and block insulation, used to cover flat or irregular surfaces such as boilers, vessels, tanks, and ductwork. Both products were engineered for high-temperature industrial applications, marketed to facilities where process heat conservation and equipment protection were priorities.

Fibreboard-Pabco was a major manufacturer operating under the Fibreboard Corporation umbrella, a company that produced a wide range of building and insulation materials throughout much of the twentieth century. The Pabco brand was associated specifically with industrial insulation products, and the Super Caltemp line represented one of the company’s offerings in the commercial and heavy industrial insulation market. These products were sold and installed across multiple industries, including petrochemical processing, power generation, shipbuilding, and manufacturing, during the approximately two decades they were in production.

The pipe covering version of Super Caltemp was typically formed in half-round or sectional shapes that could be fitted around pipes of various diameters, secured in place, and often finished with a jacketing material. The block insulation was cut or molded into rectangular forms suitable for application against flat equipment surfaces. Both configurations were designed to withstand sustained elevated temperatures while maintaining their structural integrity during normal industrial use.

Asbestos Content

Pabco Super Caltemp pipe covering and block insulation contained chrysotile asbestos as a primary component of their formulation. Chrysotile, also known as white asbestos, was the most commercially common form of asbestos used in the United States insulation industry during the mid-twentieth century. Its properties — heat resistance, tensile strength, and the ability to bind with other materials — made it well suited for high-temperature insulation products.

In products like Super Caltemp, chrysotile fibers were typically combined with binding agents, calcium silicate, diatomaceous earth, or similar mineral compounds to produce a material that could be molded, set, and applied to industrial surfaces. The asbestos fibers served as a reinforcing matrix within the insulation body, contributing both thermal stability and mechanical cohesion to the finished product.

The inclusion of chrysotile in these products was consistent with standard manufacturing practices of the era. Insulation manufacturers across the industry incorporated asbestos into pipe and block products throughout the 1950s, 1960s, and into the early 1970s, before regulatory attention and emerging health evidence led to reformulation and eventual phase-out. Fibreboard-Pabco’s use of asbestos in Super Caltemp fell within this broader industrial context.

How Workers Were Exposed

Workers who installed, maintained, repaired, or removed Pabco Super Caltemp products faced the primary risk of asbestos fiber exposure. Industrial workers generally — across the range of facilities where these insulation products were applied — encountered Super Caltemp in conditions that could generate airborne asbestos dust.

During initial installation, pipe covering sections and insulation blocks were often cut, trimmed, or shaped on the job site to fit specific equipment configurations. These cutting and fitting operations broke the hardened insulation matrix and released chrysotile fibers into the surrounding air. Workers performing this work, as well as those working nearby in the same area, could inhale fibers without adequate respiratory protection, which was typically not provided or required during this period.

Maintenance activities created ongoing exposure risks throughout the service life of the installed insulation. Industrial facilities routinely required insulation to be removed and replaced during equipment repairs, pipe replacements, or scheduled maintenance shutdowns. Workers who disturbed aged or damaged Super Caltemp insulation — particularly material that had dried, cracked, or deteriorated over years of service — encountered friable conditions in which fibers were more easily released.

Bystander exposure was also a documented concern in industrial environments. Workers whose primary job tasks did not directly involve insulation could still be exposed if they worked in proximity to insulation installation or removal activities. In enclosed or poorly ventilated industrial spaces, airborne fiber concentrations from insulation work could affect a wide area and multiple trades simultaneously.

The period during which Super Caltemp was produced and most actively installed — 1952 through 1972 — preceded the Occupational Safety and Health Administration’s establishment of enforceable asbestos permissible exposure limits and mandatory respiratory protection requirements. Workers during this era had limited regulatory protection and, in many cases, limited awareness of the health hazards associated with asbestos fiber inhalation.

Chrysotile asbestos exposure is associated with the development of serious diseases including mesothelioma, asbestos-related lung cancer, asbestosis, and pleural disease. These conditions typically have long latency periods, often appearing decades after initial exposure.