Durez thermoset resins

Durez Thermoset Resins

Product Description

Durez thermoset resins were a line of industrial-grade phenolic and other thermosetting resin compounds manufactured by Durez Corporation, a company that became one of the prominent names in the synthetic resin and plastics industry during the twentieth century. Phenolic thermoset resins of the Durez type were widely used across heavy industry, manufacturing, and chemical processing applications because of their exceptional heat resistance, dimensional stability, and electrical insulating properties. Once cured, these materials cannot be re-melted or reshaped—a characteristic that made them particularly attractive for demanding industrial environments where temperatures, mechanical stress, and chemical exposure were persistent concerns.

Durez-branded resin products were used in the production of molded industrial components, electrical insulators, brake linings, friction materials, coatings, adhesives, and laminated panels. They were supplied in multiple forms, including powders, granules, and liquid solutions, and were processed by industrial facilities across a range of sectors including aerospace, automotive, electrical manufacturing, and general heavy industry. Because of their versatility and durability, Durez resins became a common material in mid-twentieth-century industrial production.

The company’s history involves multiple ownership transitions and corporate reorganizations over the decades, which is relevant to understanding the litigation landscape surrounding Durez-branded products and the exposure claims associated with them.

Asbestos Content

Litigation records document that certain Durez thermoset resin formulations contained asbestos as a compounding ingredient or filler material. In the phenolic resin industry during the mid-twentieth century, asbestos fiber—particularly chrysotile and, in some applications, amphibole varieties—was incorporated into resin matrices to enhance heat resistance, mechanical strength, and dimensional stability under high-temperature processing conditions. Asbestos fillers were a known and commercially accepted component of molded phenolic compounds during this era.

Plaintiffs alleged that Durez resin products, particularly those formulated for high-heat or friction applications, included asbestos as a functional constituent of the compound. The specific fiber types, concentrations, and the full range of product lines alleged to have contained asbestos have been subjects of dispute in litigation. Documentation introduced in legal proceedings has included product formulation records, material safety information from the period of manufacture, and industry-standard specifications that called for asbestos-containing filler materials in phenolic molding compounds.

It is important to note that not all Durez thermoset resin formulations necessarily contained asbestos, and the presence of asbestos in any specific batch or product line is a factual question addressed through discovery and expert testimony in individual cases.

How Workers Were Exposed

Industrial workers who handled, processed, or worked in proximity to Durez thermoset resins represent the population most frequently identified in litigation as having sustained potential asbestos exposure. Plaintiffs alleged that exposure occurred through several distinct pathways associated with the industrial use of these resin compounds.

Mixing and compounding operations presented one significant exposure pathway. Workers who weighed, blended, or transferred raw resin powders or granules—particularly in facilities that processed the material before final molding—could generate airborne dust containing asbestos fibers. Phenolic resin powders are inherently fine-particle materials, and any asbestos filler present in the compound would become part of that airborne dust profile.

Molding and pressing operations also generated dust and particulate. Workers operating compression or transfer molding presses, trimming flashing from finished parts, or inspecting and finishing molded components could be exposed to fine dust released during these processes.

Machining and finishing represented another significant exposure route documented in litigation. Drilling, grinding, sanding, and cutting cured phenolic components—even after the resin matrix was fully hardened—could release asbestos fibers embedded within the material. Litigation records document claims from workers who performed secondary fabrication of Durez-type phenolic parts in manufacturing and industrial settings.

General industrial proximity was also cited by plaintiffs. Workers in facilities where Durez resins were used in large quantities—such as electrical equipment manufacturing plants, brake and friction component facilities, and chemical processing operations—may have sustained exposure through ambient airborne fiber contamination in shared work environments, even if they were not directly handling the resin products themselves.

The trades and occupational categories most represented in litigation involving Durez thermoset resins include general industrial laborers, plastics and composites workers, machinists, press operators, and maintenance workers who serviced equipment used in resin processing. The relevant exposure period spans approximately from the 1940s through the late 1970s, corresponding to the era during which asbestos was most commonly used as an industrial filler material before regulatory action by the Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA) curtailed its use.

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.