Narcogun CM-343 Spray Fireproofing

Product Description

Narcogun CM-343 was a spray-applied fireproofing material manufactured by Narco and sold primarily for use in industrial and commercial construction settings. Produced during the period from 1965 through 1977, the product was designed to meet fire-resistance requirements by coating structural steel, decking, and other building components with a thick, insulating layer of material applied under pressure through specialized spray equipment.

Spray-applied fireproofing of this type became a standard feature of large-scale industrial and commercial construction during the postwar decades. Building codes in many jurisdictions required that structural steel framing be protected against the effects of high heat, which can cause steel to lose load-bearing integrity. Products like Narcogun CM-343 fulfilled that requirement by adhering to steel surfaces and forming a thermally resistant barrier intended to slow the transfer of heat during a fire event.

The Narcogun CM-343 product line was marketed under Narco’s brand and distributed to contractors engaged in industrial construction, including manufacturing facilities, power plants, warehouses, and similar large-footprint structures built during the 1960s and 1970s. Its formulation and delivery system were characteristic of the wet-spray fireproofing technologies in widespread use throughout that era.

Asbestos Content

Narcogun CM-343 contained chrysotile asbestos as a functional component of its formulation. Chrysotile, sometimes referred to as white asbestos, is a serpentine-form mineral fiber that was extensively used in spray-applied fireproofing products because of its heat resistance, tensile strength, and ability to bond with binding agents to form a durable, adhering coating.

In spray fireproofing applications, chrysotile asbestos fibers were typically combined with Portland cement, mineral wool, or other binders and mixed with water to create a slurry that could be projected onto surfaces through a spray nozzle. The asbestos fibers served both as a reinforcing matrix and as a heat-resistant component of the finished coating.

Chrysotile asbestos has been classified as a known human carcinogen by the International Agency for Research on Cancer (IARC) and is regulated as a hazardous material under OSHA’s asbestos standards (29 CFR 1910.1001 and 29 CFR 1926.1101). The U.S. Environmental Protection Agency’s Asbestos Hazard Emergency Response Act (AHERA) framework also addresses chrysotile-containing building materials, requiring identification and management of such materials in certain regulated environments.

Despite industry claims in earlier decades that chrysotile posed fewer health risks than amphibole asbestos varieties, scientific and regulatory consensus has firmly established that occupational exposure to chrysotile asbestos fibers is associated with mesothelioma, asbestosis, lung cancer, and other serious diseases.

How Workers Were Exposed

Workers exposed to Narcogun CM-343 fell primarily into the broad category of industrial workers involved in the construction, maintenance, renovation, or demolition of facilities where the product was applied. Because Narcogun CM-343 was a spray-applied product, the nature of its application created significant potential for airborne fiber release throughout multiple phases of a building’s lifecycle.

During Application: Workers operating spray equipment mixed dry or pre-bagged Narcogun CM-343 with water and projected the resulting slurry onto structural steel and other surfaces. This process generated visible clouds of dust and aerosolized material. Workers in the immediate area, including spray equipment operators and helpers, experienced direct exposure to airborne asbestos fibers. Nearby tradespeople working in the same open structure, such as ironworkers, pipefitters, electricians, and laborers, were also present in the work environment during spray operations and were exposed to fibers that remained suspended in the air or settled on surfaces throughout the work area.

During Drying and Finishing: After application, the fireproofing material required time to cure. Workers who entered areas where freshly applied Narcogun CM-343 was drying, or who disturbed the coating during finishing operations, risked dislodging fibers from the partially set material.

During Maintenance and Renovation: Buildings constructed with spray fireproofing products applied in the 1960s and 1970s frequently required maintenance work on mechanical systems, utilities, and structural components. Workers who drilled into, cut around, or otherwise disturbed Narcogun CM-343 fireproofing during routine maintenance or renovation work were exposed to fibers released from the damaged coating. Industrial facilities in particular required ongoing maintenance that brought workers into repeated contact with existing fireproofing materials over many years.

During Demolition: Workers involved in demolishing or salvaging structures containing Narcogun CM-343 fireproofing faced exposure when the material was broken apart, removed, or disturbed in bulk. Prior to modern asbestos abatement regulations, this demolition work often proceeded without respiratory protection or wet-suppression methods.

The friable nature of spray-applied chrysotile fireproofing is well-documented in occupational health literature. Friable asbestos-containing materials can be crumbled by hand pressure, releasing fibers into the air. OSHA and EPA regulations specifically address friable spray-applied asbestos fireproofing as among the highest-risk categories of asbestos-containing building material.

Narcogun CM-343 is a Tier 2 product for purposes of legal remedy, meaning that no dedicated asbestos bankruptcy trust has been established specifically to compensate claimants for exposure to this product. Legal options for individuals injured by exposure to Narcogun CM-343 involve civil litigation in the tort system rather than administrative trust fund claims.

Litigation records document claims brought against Narco and, in many cases, against other defendants in the asbestos litigation system in connection with spray-applied fireproofing exposures. Plaintiffs alleged that manufacturers of asbestos-containing spray fireproofing products, including products of this type, knew or should have known that their products released hazardous asbestos fibers during normal use and that they failed to adequately warn workers of those hazards.

Plaintiffs alleged that this failure to warn, combined with the widespread use of products like Narcogun CM-343 in industrial settings, caused or contributed to the development of mesothelioma, lung cancer, and asbestosis in workers who were exposed during their careers.

Because no Narco-specific trust fund exists, individuals seeking compensation for Narcogun CM-343-related injuries should consult with an attorney experienced in asbestos litigation. Depending on the facts of a given case, additional claims may be available against other parties in the exposure chain, including building owners, general contractors, and other product manufacturers whose materials were present at the same job sites.

Diagnosed individuals or surviving family members should gather employment records, union records, co-worker testimony, and any available documentation of the products present at worksites where exposure occurred. This documentation is essential to supporting a civil asbestos claim.

This article is provided for informational and reference purposes. It does not constitute legal advice. Individuals with questions about asbestos exposure or legal options should consult a qualified attorney.