Boilers — Asbestos Exposure Crosswalk

What This Equipment Is

Industrial boilers are pressurized vessels that generate steam or hot water by burning fuel (coal, natural gas, oil) or by using waste heat from another process. They are the heart of every power plant, brewery, refinery, steel mill, hospital, paper mill, and large industrial facility built before the 1980s. A working boiler runs hot — typically 350°F to 1,000°F or higher — and is wrapped in heavy thermal insulation from base to crown.

Boilers themselves are not made of asbestos. The asbestos exposure comes from the surrounding materials that were specified to keep the heat in and the safety hazards down.

Asbestos Products Historically Used in Boilers

Product CategoryWhere in the BoilerNotes
Block insulationBoiler shell, drum, breechingCalcium silicate or magnesia block
Pipe coveringSteam outlet lines, feedwater linesMagnesia, calcium silicate, fiberglass-asbestos
Insulating cementJoints, fittings, irregular surfacesMixed dry, hand-applied, very dusty
Refractory brickFurnace lining, combustion chamberHigh-temp duty, some grades asbestos-bonded
GasketsManway covers, handhole covers, flangesSheet gasket material, spiral wound
PackingValve stems, pump shafts on boiler feedBraided asbestos rope
Boiler jacketsOuter claddingAsbestos cloth, millboard, transite
FireproofingStructural steel around boilerSpray-applied or troweled

Manufacturers Named in Boiler-Insulation Litigation

Public asbestos litigation records identify the following manufacturers as defendants in cases involving boiler insulation, gaskets, packing, or refractory:

  • Johns-Manville — block insulation, pipe covering, refractory
  • Owens-Corning / Fibreboard — pipe covering, block insulation
  • Eagle-Picher — block insulation
  • Combustion Engineering — boiler manufacturer named in installation/maintenance claims
  • Babcock & Wilcox — boiler manufacturer named in installation/maintenance claims
  • Armstrong World Industries — calcium silicate insulation
  • Pittsburgh Corning — Unibestos pipe covering
  • Garlock Sealing Technologies — sheet gaskets, packing
  • W.R. Grace — fireproofing and insulating products
  • Crane Co. — valves, gaskets, packing supplied with boiler systems

Documented Product References

Images sourced from publicly available product-identification reference materials. Inclusion does not constitute a finding of liability against any company.

Trust Funds That May Apply

  • Manville Personal Injury Settlement Trust
  • Owens-Corning / Fibreboard Asbestos Personal Injury Trust
  • Babcock & Wilcox Company Asbestos PI Trust
  • Combustion Engineering 524(g) Asbestos PI Trust
  • Eagle-Picher Industries Personal Injury Settlement Trust
  • Pittsburgh Corning Corporation Asbestos PI Trust
  • Armstrong World Industries Asbestos PI Settlement Trust

Trades Most Exposed at Boilers

Boilermakers, pipefitters, insulators (Heat & Frost Insulators), millwrights, electricians working in boiler rooms, maintenance mechanics, and laborers doing tear-out during outages.

Jobsites in the Network Documenting Boilers


Compiled from publicly filed asbestos litigation, EPA / state-DNR records, and industry-publication histories. Product identifications and company references reflect what has been alleged or documented in publicly filed litigation. This page does not constitute a finding of liability against any company. This information is not legal advice; consult a licensed attorney about your specific situation.