Product Description

General Electric built the large industrial motors, generators, and transformer coils that ran U.S. steel mills, paper mills, refineries, utility plants, and Navy shipyards throughout the mid-twentieth century. Inside every one of those machines, the copper windings had to be electrically insulated from each other, from the iron core, and from ground. GE used a layered insulation system built around three asbestos-containing components:

  • Asbestos-cloth coil-lead wrap — woven asbestos tape or braided asbestos sleeving wound around the exposed copper leads exiting the coil ends, providing heat resistance where the coil connected to the terminal box.
  • Asbestos-varnish impregnated coil-end insulation — the exposed end-turns of stator and armature coils were dipped in a phenolic or shellac varnish loaded with asbestos fiber, then baked, producing a hard fiber-reinforced dielectric shell over the coil end.
  • Asbestos-fiber slot liners — the paper- or millboard-form insulation strip that lined the iron slot before the copper was set into place, containing either raw asbestos millboard or asbestos-paper laminate.

Plaintiffs alleged in publicly filed U.S. asbestos litigation that GE manufactured its large-motor, generator, and transformer coils with these asbestos-containing insulation systems from the 1940s through November 21, 1972, the date GE corporate representatives have testified that its heat-resistant electrical insulation product lines transitioned away from asbestos.

Workers Exposed

The exposure pathway ran through motor-repair shops — both GE’s own service centers and the thousands of independent motor-rewind shops that serviced GE equipment nationwide. When a large GE motor came in for rewind, the shop procedure required:

  1. Coil pull — burning the old varnish off in a bake-out oven or cutting the coil ends off with a torch, releasing fibers from the degraded asbestos-varnish shell.
  2. Slot cleaning — chipping and scraping the old slot liner residue out of every stator slot, disturbing bonded asbestos-paper material.
  3. Rewind and re-varnish — installing fresh asbestos-cloth lead wrap and fresh asbestos slot liners, cutting and fitting each piece by hand.
  4. Dip and bake — dipping the completed coil assembly in asbestos-filled varnish and baking it hard, with the workshop atmosphere loaded with fiber during the operation.

Plaintiffs alleged that motor-shop electricians, industrial electricians, winders, coil-pullers, and millwrights performed this work without respiratory protection, without wet-methods dust control, and without any warning labeling identifying the coil insulation as asbestos-containing.