CM-18 Gun Mix

Product Description

CM-18 Gun Mix was a refractory castable product manufactured by Keene Corporation, a company with a broad industrial product portfolio that included numerous building materials and specialty construction compounds throughout much of the twentieth century. Gun mixes of this type were engineered for pneumatic application—commonly referred to as “gunning”—in which mixed material was conveyed through a hose and nozzle system and sprayed or projected onto surfaces at high velocity. This application method made the product suitable for lining industrial furnaces, kilns, boilers, incinerators, and other high-temperature processing equipment where refractory protection was required to withstand extreme thermal conditions.

The term “gun mix” refers to the product’s consistency and particle sizing, which were formulated specifically to flow through pneumatic gunning equipment without clogging. Once applied and cured, CM-18 Gun Mix created a dense, heat-resistant lining designed to protect structural substrates from radiant heat, flame impingement, and thermal cycling. Products in this category were widely used in steel mills, foundries, petrochemical refineries, power generation facilities, and other heavy industrial settings where continuous high-temperature operations demanded durable refractory linings that could be installed or repaired quickly.

Keene Corporation marketed products across multiple industrial sectors, and litigation records document that CM-18 Gun Mix was among the asbestos-containing materials associated with the company’s product line during the period in which asbestos was commonly incorporated into refractory and fireproofing compounds.

Asbestos Content

Refractory gun mixes produced during the mid-twentieth century frequently incorporated asbestos fibers, primarily because asbestos offered a combination of properties that were difficult to replicate with alternative materials at the time. Asbestos fibers contributed tensile reinforcement to the castable matrix, helped control cracking during thermal cycling, improved resistance to thermal shock, and enhanced the material’s ability to adhere to vertical and overhead surfaces during pneumatic application.

Plaintiffs alleged in litigation involving Keene Corporation and its affiliated product lines that CM-18 Gun Mix contained asbestos as a functional component of its formulation. The precise fiber type and percentage by weight documented in surviving product specifications may vary depending on the production period and intended application, but litigation records document that asbestos content was a material characteristic of the product as manufactured and sold during the relevant period.

Because specific asbestos percentage data for CM-18 Gun Mix has not been independently published in publicly available regulatory filings reviewed for this article, the exact formulation details are drawn from the litigation record rather than from product specification sheets or Material Safety Data Sheets (MSDS).

How Workers Were Exposed

Workers in heavy industrial environments where CM-18 Gun Mix was applied, maintained, or disturbed faced potential exposure to asbestos fibers through several distinct pathways. Industrial workers generally—including those employed in steel production, power generation, chemical processing, petroleum refining, and other manufacturing industries—represented the primary exposed population documented in litigation records.

Application and Installation: The pneumatic gunning process was a significant source of airborne fiber generation. When mixed material was propelled through nozzle equipment and impacted target surfaces, fine dust and fiber clouds could be released into the work environment. Workers operating gunning equipment, as well as those working nearby, were potentially in the path of airborne material generated during application.

Mixing and Preparation: Before pneumatic application, dry gun mix material had to be blended and introduced into the delivery system. Tearing open bags, emptying containers, and agitating dry mix created dust that could contain respirable asbestos fibers. Workers performing this preparatory work in enclosed or poorly ventilated areas faced elevated exposure potential.

Cutting, Grinding, and Surface Preparation: Where existing refractory linings required repair or replacement, workers often used mechanical tools to break out, chip, or grind away old material before applying new gun mix. Disturbing cured refractory containing asbestos generated fiber concentrations that could remain suspended in air for extended periods.

Boiler and Furnace Maintenance: Industrial maintenance personnel who entered boilers, kilns, furnaces, or other equipment lined with CM-18 Gun Mix for inspection, cleaning, or repair work faced exposure when the refractory lining was in a deteriorated or damaged condition. Spalling, cracking, and general wear of refractory surfaces over time released fibers into enclosed spaces.

Bystander Exposure: Plaintiffs alleged that workers who were not directly involved in gunning or refractory work but who performed other tasks in the same industrial areas were also exposed to asbestos fibers liberated from CM-18 Gun Mix during application and disturbance. This bystander exposure was documented across multiple trades and job classifications working in heavy industrial plants.

Asbestos-related diseases associated with occupational inhalation exposure include mesothelioma, asbestosis, asbestos-related lung cancer, and pleural disease. These conditions typically have latency periods of decades between initial exposure and clinical diagnosis.