Durez Asbestos-Filled Phenolic Molding Compound

Product Description

Durez phenolic molding compounds were industrial thermosetting plastics manufactured by Durez Corporation, a company that operated as a significant supplier of synthetic resin materials to American industry throughout the twentieth century. Phenolic resins — commonly known by the generic name Bakelite-type materials — were among the earliest synthetic plastics developed for commercial use, prized for their exceptional heat resistance, electrical insulating properties, dimensional stability under load, and resistance to chemical attack.

Durez compounds were formulated in various grades to meet the demands of specific industrial applications. These materials were processed through compression molding, transfer molding, and injection molding techniques to produce finished components such as electrical connectors, circuit breaker housings, motor brush holders, appliance handles, automotive parts, industrial valve components, and a wide range of structural and insulating hardware. The resulting molded parts were integrated into products found across virtually every sector of American manufacturing, including the electrical, automotive, aerospace, and heavy industrial trades.

The Durez brand became well established among manufacturers and fabricators who required a moldable plastic capable of withstanding elevated temperatures and mechanical stress in service conditions where conventional thermoplastics would fail. This widespread industrial adoption meant that Durez molding compounds were processed in a broad range of manufacturing facilities over many decades.

Asbestos Content

Phenolic molding compounds of the type produced under the Durez name were formulated with a variety of fillers and reinforcing agents intended to modify the physical and thermal properties of the finished resin. Among the filler materials used in certain grades of phenolic molding compound was asbestos fiber.

Asbestos was valued in thermoset plastic formulations for several reasons. Its fibrous structure reinforced the resin matrix, improving tensile and flexural strength. Its well-known thermal stability extended the service temperature range of the finished molded part, making asbestos-filled grades particularly suitable for electrical and high-heat applications. Its resistance to flame and arc tracking made it attractive to manufacturers of electrical switchgear and related components.

Litigation records document that Durez Corporation produced phenolic molding compounds containing asbestos fiber as a filler or reinforcing constituent. The precise grades affected, the fiber types employed, and the concentration levels varied across product formulations, and detailed composition data for specific lots may be found in historical material safety data sheets, internal company documents, and records produced during discovery in asbestos litigation.

How Workers Were Exposed

Workers who processed Durez asbestos-filled phenolic molding compounds were potentially exposed to airborne asbestos fibers at multiple stages of the molding and fabrication process. Plaintiffs in asbestos litigation alleged that these exposures occurred without adequate warning of the health hazards associated with asbestos inhalation.

Molding operations presented a primary route of exposure. Phenolic molding compounds were supplied as granular or pelletized material, and handling this feedstock — including pouring, weighing, and loading into molding presses — could generate airborne dust containing asbestos fibers. Workers who routinely handled bulk quantities of molding compound in production environments faced repeated exposure during these tasks.

Compression and transfer molding generated heat and pressure that could release fine particulate from the compound. Flash — the thin film of excess material that squeezed out along parting lines — was routinely removed by grinding, sanding, or tumbling, operations that litigation records document as generating respirable dust that could contain asbestos.

Post-mold finishing operations were another significant source of exposure. Deflashing, trimming, drilling, grinding, and sanding of molded phenolic parts produced airborne dust. Workers performing these tasks in production environments were often in sustained contact with the resulting particulate, particularly where ventilation was inadequate.

Maintenance and tooling work in molding facilities brought additional workers into contact with compound residue and mold flash. Mold cleaners, press mechanics, and quality control inspectors who moved through production areas shared the ambient air with molding line operators.

Industrial workers generally — the broad category encompassing the trades most commonly documented in litigation involving Durez phenolic compounds — include those employed in electrical component manufacturing, automotive parts production, and general industrial fabrication facilities where phenolic molding was performed. Plaintiffs alleged that workers in these environments were not adequately informed of the presence of asbestos in the compound or of the respiratory risks associated with inhaling asbestos-containing dust.

The latency period characteristic of asbestos-related diseases — often ranging from ten to fifty years between first exposure and clinical diagnosis — means that workers exposed to Durez phenolic molding compounds during peak production decades may only now be receiving diagnoses of mesothelioma, asbestosis, lung cancer, or other asbestos-related conditions.

This article is provided for informational reference purposes and documents publicly available information about Durez asbestos-filled phenolic molding compound. It does not constitute legal advice. Individuals seeking guidance regarding a potential asbestos claim should consult a qualified attorney.

Documented Product Identification

The following details are drawn from public asbestos litigation records, manufacturer catalog pages, technical manuals, and corporate history materials. Each item reflects the product as documented in those sources.

Documented asbestos-use period: 1972

Corporate context: Durez Division was a division of Hooker Chemical Company. Hooker Chemical Company later became part of Occidental Chemical Corporation (Occidental).

Documented asbestos components: Calidria RG-244 asbestos (thixotroping additive).

Documented asbestos-component suppliers: the public records lists the following external suppliers of asbestos-bearing packing, gaskets, and seals used in conjunction with this manufacturer’s equipment — Union Carbide (Calidria RG-244 asbestos).

Industries served: Structural resins, Polyester resin manufacturing.

Documented product lines:

• DRH-323 (Polyester Resin DRH-323) (1972). A structural vinyl resin made by thixotroping EPOCRYL Resin 21 with Union Carbide Calidria RG-244 asbestos and water for use as a thixotroped polyester resin. — asbestos components: Calidria RG-244 asbestos thixotroping agent.

Durez Division of Hooker Chemical Company purchased EPOCRYL Resin 21 from Shell Chemical Company and thixotroped it with Union Carbide Calidria RG-244 asbestos for resale as DRH-323. Shell Chemical Company manufactured the asbestos-containing resin under contract for Durez/Hooker.