Plenco (Plastics Engineering Company) was founded in Chicago, Illinois in 1934 and later relocated its primary operations to Sheboygan, Wisconsin. The company was one of the six principal manufacturers of phenolic molding compounds in the U.S. during the asbestos era, alongside Durez, Reichhold, General Electric, Rogers, and Acme. Plenco supplied asbestos-filled phenolic compound to molding shops, electrical component manufacturers, and industrial customers across the country.

Asbestos use period

Industry records document Plenco as actively phasing out asbestos-filled phenolic molding compounds around 1972. A 1972-era industry survey notes: “Durez and Plenco will capture a share of this business since they are in the process of phasing their asbestos products out. Durez, for example, withdrew 90% of its asbestos-filled materials from the market at the end of June.” By the time of a mid-1970s industry survey referencing 1974 consumption data, all six principal suppliers of phenolic molding compounds — including Plenco — offered asbestos-free heat-resistant grades.

The transition was not simultaneous across all grades. Plenco certified that specific compound formulations had been reformulated to eliminate asbestos (see below), indicating the phase-out occurred on a grade-by-grade basis rather than all at once.

Grade-specific reformulation records

Plenco’s own certification documents, produced in publicly filed litigation, identify specific compound formulations that were reformulated to eliminate asbestos:

  • Plenco 574, 482, and 571 — certified by Plenco as “formulated without any asbestos or asbestos compound fillers”
  • Plenco 308 and 548 — “reformulated and all asbestos has also been eliminated from these two compounds”
  • Plenco 509 — listed in industry records as an asbestos-free general-purpose phenolic molding compound

Workers who used Plenco compound grades other than those identified in the reformulation certifications, or who used any Plenco grade prior to the early 1970s reformulation period, may have worked with asbestos-containing material.

Plants

  • Chicago, Illinois (1934–1950s) — original founding location and early manufacturing
  • Sheboygan, Wisconsin — primary operations through the asbestos era and current operations

GE phenolic compound acquisition (1982)

In 1982, Plenco acquired General Electric’s phenolic molding compound business. Workers who used GE-brand phenolic compound before 1982, and workers who used Plenco compound produced from the former GE product lines after 1982, may have exposure histories that involve both companies through this acquisition.

Litigation history

Plenco has been named as a defendant in asbestos-phenolic compound cases involving both Sheboygan compound-manufacturing employees and downstream molding-shop workers. Plenco’s 2016 interrogatory responses in publicly filed litigation cover the period “prior to and including 1990” as a relevant exposure window — reflecting that claims have involved workers employed well into the 1970s and 1980s.

Worker exposure pathways at Plenco plants

Workers at the Sheboygan Plenco operation were exposed during raw asbestos handling, compound formulation, pelletizing, packaging, and shipping of asbestos-filled phenolic compound. The documented phase-out timeline beginning around 1972 means workers employed prior to that date, and workers who handled grades not yet reformulated, faced the highest exposure risk.

Downstream molding-shop workers throughout the Midwest who received Plenco compound experienced exposure during compound handling, hopper loading, compression and transfer molding, flash trimming, tumbling, and finishing operations.

If you worked with Plenco asbestos-phenolic compounds

Worker exposure documentation includes: pay stubs and W-2s showing employment dates, social security earnings records, union dispatch records (for shop members), and any compound identification — grade numbers, lot codes, or bag labels — that can establish which specific Plenco formulations were in use at your facility.

If you used GE phenolic compound before 1982 or Plenco compound manufactured from former GE product lines after 1982, that employment history may also be relevant to your claim.

Free, confidential case evaluation: Speak with O’Brien Law Firm — (314) 936-2956

All consultations are free. No fee unless a financial recovery is made on your behalf.

References to manufacturers, products, and litigation history reflect what has been alleged or documented in publicly filed asbestos litigation, corporate discovery records, and industry archives. This information does not constitute a finding of fact or liability. This site does not provide legal or medical advice.