NEMA Grades Reference

Product Description

NEMA (National Electrical Manufacturers Association) industrial laminate grade designations identify standardized industrial laminate compositions used across the U.S. electrical and industrial equipment industries. Many NEMA grades produced during the asbestos era used asbestos cloth or asbestos paper as the reinforcement web.

Asbestos-bearing NEMA grades produced during the asbestos era include:

  • XX, XXX, XXXP — Paper-phenolic grades; XX-grade variants used asbestos paper as the reinforcement web for higher-temperature applications
  • C, CE — Cotton-fabric-phenolic grades; some specialized variants used asbestos cloth instead of cotton for industrial heater terminal blocks
  • L, LE — Linen-fabric-phenolic grades; asbestos cloth variants for high-arc-resistance applications
  • A — Asbestos-cloth-phenolic (designation specifically for asbestos cloth construction)
  • G-3 — Coarse glass cloth / phenolic (some asbestos-era variants used asbestos cloth)
  • G-5 — Heat-resistant glass / melamine (some asbestos-era variants)
  • G-7 — Silicone / glass cloth; asbestos-era variants used asbestos cloth and silicone for 220°C operating temperature
  • G-9 — Melamine / glass cloth; asbestos-era variants used asbestos cloth and melamine for arc-resistance
  • G-10, FR-4 — Modern epoxy/glass grades (not asbestos-bearing)

Major NEMA-grade laminate producers during the asbestos era included Westinghouse Micarta, General Electric Textolite, Synthane Taylor, Spaulding Fibre, Continental Diamond Fibre, National Vulcanized Fibre, Rogers Corporation, and Plenco.

Workers at NEMA-grade laminate production plants and at downstream customer fabrication shops experienced exposure during raw asbestos handling, lamination pressing, sheet cutting, machining, drilling, and finishing operations.

Asbestos Content

Litigation records document that NEMA Grades Reference was alleged to have contained asbestos fiber as a functional filler or reinforcing agent. Asbestos fibers were incorporated into industrial materials of this category to enhance heat resistance, mechanical strength, dimensional stability under thermal cycling, and electrical-insulation properties.

Plaintiffs alleged that asbestos fibers in NEMA Grades Reference were typically chrysotile, amosite, or a combination thereof — consistent with industry practice for the asbestos era. When the cured material was subjected to mechanical operations (drilling, grinding, sanding, machining, cutting) or when raw material was handled and processed, those fibers could become airborne.

How Workers Were Exposed

Litigation records document multiple exposure pathways for workers who handled NEMA Grades Reference:

Raw material handling: Workers who received, weighed, blended, or transferred the material in production environments could disturb settled asbestos fibers and generate airborne dust.

Manufacturing operations: Workers operating the production equipment — molding presses, lamination presses, compounding mixers, cutting saws — were exposed during normal operation, equipment cleaning, and routine maintenance.

Machining and finishing of finished material: Secondary operations including drilling, reaming, turning, grinding, sanding, sawing, and routing of NEMA Grades Reference generated fine dust containing asbestos fibers. These operations were performed by machinists, toolmakers, electricians, and assembly workers who may not have been informed that the material contained asbestos.

Maintenance and tooling work: Maintenance workers responsible for cleaning equipment, servicing presses and mixers, and disposing of accumulated dust in facilities that produced or processed NEMA Grades Reference could encounter substantial exposure during cleaning and repair operations.

The occupational exposures associated with asbestos-containing industrial laminates and molding compounds are consistent with patterns recognized by OSHA and NIOSH. The latency period for asbestos-related diseases is typically 20-50 years between initial exposure and diagnosis, meaning workers exposed to products like NEMA Grades Reference during the mid-twentieth century may be receiving diagnoses today.

See also

References to manufacturers, products, and litigation history reflect what has been alleged or documented in publicly filed asbestos litigation. This information does not constitute a finding of fact or liability.