Major Asbestos Pipe Insulation Brands
Dozens of manufacturers produced asbestos-containing pipe insulation throughout the 20th century. The following brands were among the most widely used and have been identified in thousands of asbestos litigation cases and trust fund claims:
| Brand Name | Manufacturer | Years Made | Notes |
|---|---|---|---|
| Kaylo | Owens Corning Fiberglass | 1943–1972 | Molded calcium silicate pipe covering; widely used in power plants, refineries, and industrial facilities. Owens Corning knew of health hazards by the 1950s. |
| Unibestos | Pittsburgh Corning Corp. | 1942–1972 | Glass-fiber and asbestos composite insulation; used heavily in U.S. Navy shipbuilding and industrial piping systems. |
| Pabco | Philip Carey Co. | 1920–1970 | Magnesia-asbestos pipe covering; one of the earliest and most widely distributed brands across all industries. |
| Magnesia 85 | Various manufacturers | 1900–1970 | 85% magnesia and 15% asbestos composite; the standard pipe insulation specification for U.S. Navy vessels for decades. |
| Thermobestos | H.W. Johns Manufacturing | 1930–1965 | Standard pipe lagging product used across commercial and industrial construction. |
| Sprayed Limpet | Cape Asbestos Co. | 1940–1970 | Spray-applied asbestos insulation; the most hazardous application method due to extremely high airborne fiber concentrations during spraying. |
| Air-Cell | Johns-Manville | 1930–1972 | Corrugated asbestos pipe covering with air gaps for additional insulation value; used in commercial heating systems. |
| Hy-Temp | Armstrong World Industries | 1940–1975 | High-temperature asbestos insulation for process piping in chemical and petrochemical plants. |
Who Was Most Exposed to Asbestos Pipe Insulation?
Asbestos pipe insulation created exposure for two distinct groups: the workers who installed it, and the workers who later removed or disturbed it. Both groups faced serious health risks, often without any protective equipment or safety warnings from their employers or the product manufacturers.
Insulators and Laggers
Insulators — also called laggers or asbestos workers — applied pipe insulation directly as part of their daily trade. A typical day involved cutting Kaylo or Unibestos sections with handsaws, mixing asbestos cement to seal joints, and smoothing the finished surface with asbestos-containing finishing compounds. This work created extremely high concentrations of airborne fibers. Studies of insulator unions show mesothelioma rates 8 to 10 times higher than the general population.
Pipefitters and Steamfitters
Pipefitters worked adjacent to insulators, often in confined spaces with poor ventilation. When pipefitters repaired or modified pipe systems, they had to remove and replace the surrounding insulation — work that generated significant fiber release. Studies show pipefitters and steamfitters have 8 to 13 times the normal rate of mesothelioma.
Boilermakers
Boilermakers maintained and repaired boilers, which were heavily insulated with asbestos materials including pipe lagging, block insulation, and boiler cement. Removing deteriorated insulation from boiler surfaces and pipe connections was a routine part of the job. Boilermakers show 7 to 10 times elevated mesothelioma risk.
Bystander Exposure
Electricians, painters, welders, and other tradespeople who worked in the same spaces as insulators were also exposed — even though they never directly handled asbestos products. This “bystander exposure” has been recognized by courts as sufficient to establish liability against manufacturers who failed to warn workers of the dangers of working near their products.
Industries Where Asbestos Pipe Insulation Was Used
Asbestos pipe insulation was used in virtually every industrial setting that involved steam, high-temperature fluids, or hot water systems — which meant it was present in nearly every major industry in America from the 1920s through the 1970s.
| Industry | Typical Use | Risk Level |
|---|---|---|
| Naval shipbuilding | Steam pipes, boiler rooms, engine rooms, crew quarters pipe systems; asbestos was specified in Navy contracts and used throughout every vessel | Critical |
| Power plants | Turbine steam lines, boiler insulation, condenser and feedwater pipe systems; insulation was replaced repeatedly during plant life | Critical |
| Oil refineries | Process piping, heat exchangers, distillation columns; extreme temperatures required heavy insulation throughout | Critical |
| Chemical plants | High-temperature process piping, reaction vessels, steam tracing lines | High |
| Commercial buildings | Boiler rooms, mechanical rooms, steam distribution systems in office buildings, hospitals, and hotels | High |
| Paper mills | Steam piping throughout mill operations; papermaking required continuous high-temperature steam processes | High |
| Steel mills | High-temperature process piping, annealing furnace connections, steam lines throughout facility | High |
Diagnosed with Mesothelioma?
Our sister site connects you with mesothelioma attorneys at no upfront cost.
Frequently Asked Questions
Kaylo pipe insulation was a molded calcium silicate product manufactured by Owens Corning that came in half-round sections designed to clam-shell around pipes of specific diameters. It was typically white or off-white in color with a chalky, rigid, slightly granular texture — similar in appearance to plaster. The sections were typically 3 feet long and were secured with wire or metal banding.
Workers cut Kaylo sections with hand saws or power saws to fit different pipe lengths, elbows, and valve configurations. This cutting generated heavy dust clouds containing high concentrations of asbestos fibers. Kaylo sections were typically marked with the Owens Corning name, and product documentation from the era clearly identified asbestos as a primary component. Despite this, workers were not warned of the health risks until decades later.
Yes. Many of the major asbestos pipe insulation manufacturers — including Owens Corning, Pittsburgh Corning, Philip Carey (Celotex), Armstrong, and H.W. Johns-Manville — filed for bankruptcy and established asbestos trust funds totaling tens of billions of dollars specifically to compensate workers and their families. These trusts continue to accept and pay claims today.
Under the legal “discovery rule,” the statute of limitations for an asbestos claim typically runs from the date of diagnosis, not the date of exposure. This means that even if you were exposed 30 or 40 years ago, you may still have time to file a claim after receiving a diagnosis of mesothelioma, asbestosis, or asbestos-related lung cancer.
An experienced mesothelioma attorney can review your complete work history, identify which trust funds and defendant companies apply to your situation, and file all claims on your behalf at no upfront cost. Most mesothelioma attorneys work on a contingency fee basis, meaning you only pay if you receive compensation.