The Trade That Raised America's Steel — Under a Rain of Sprayed Asbestos

Sprayed fireproofing, applied while the raising gang worked

From the mid-1950s until the 1973 EPA ban on spray-applied asbestos, structural steel was coated with sprayed asbestos fireproofing — Monokote, Cafco, and similar products — to give the steel a fire rating. On a typical high-rise or industrial job, the fireproofing crew sprayed the steel on the lower floors while the iron workers were still connecting steel on the floors above. Fiber rained down onto the raising gang, coated their tools and clothes, and hung in the air of the enclosed floors below. The iron worker did not choose or apply the material — but he worked in the middle of it every day the spray crew was on the job.

Overspray, cutting, and rework

Iron workers returning to a floor to hang iron, adjust connections, or set additional steel after fireproofing had been applied disturbed the dry, friable asbestos coating — knocking it loose, cutting through it, and re-releasing fiber. Welding and burning near sprayed steel drove off and aerosolized the coating.

Industrial jobs surrounded by asbestos-lagged equipment

On power-plant, refinery, and steel-mill erection, iron workers set the structural steel and equipment supports in and around boilers, turbines, and process piping that were wrapped in asbestos block lagging and pipe covering — being installed, cut, and torn out by other trades in the same space.

Confined spaces and inadequate ventilation

Enclosed building floors during fireproofing, the interiors of industrial structures, and the decks below active spray work were poorly ventilated when they were ventilated at all. The fiber that went into the air stayed in the air, and stayed in the worker's lungs.

Respiratory protection came too late

The EPA did not ban spray-applied asbestos fireproofing until 1973, and OSHA's first asbestos regulations came in 1971 — after nearly two decades of iron workers on sprayed-steel jobs. Even then, enforcement was uneven and respirators were not consistently required or encouraged. Most iron workers who worked the sprayed-fireproofing era completed those years with very little respiratory protection at all.

The occupational-health record

Dr. Irving Selikoff's Mount Sinai research documented elevated mesothelioma incidence across the construction trades exposed to sprayed asbestos and adjacent insulation. The disease pipeline, driven by mesothelioma's 20-to-50-year latency between exposure and diagnosis, continues today — the cohort that worked the 1950s-1973 sprayed-fireproofing era is being diagnosed now, and will be for the next two decades.

1896 — The founding

The International Association of Bridge, Structural, Ornamental and Reinforcing Iron Workers was founded on February 4, 1896, in Pittsburgh, Pennsylvania — the industrial capital of American structural steel. The union maintains its international headquarters in Washington, D.C. From the first riveted skyscrapers through the modern bolted, welded, and rebar-reinforced era, IW members have erected the structural skeleton of America's built environment.

1900s–1950s — Growth with structural steel

The trade grew alongside the steel-framed skyscraper, the long-span bridge, the industrial plant, and the power station. Iron workers erected, riveted, bolted, and welded the steel skeleton of it all. Through the early decades the fire protection for that steel was masonry and concrete encasement — but in the mid-1950s a cheaper, faster method arrived: spray-applied asbestos fireproofing.

1950s–1973 — The sprayed-fireproofing era

From the mid-1950s until 1973, sprayed asbestos fireproofing (Monokote, Cafco, and similar) was applied to structural steel on high-rise and industrial jobs across the country — frequently while iron workers were still erecting steel on adjacent floors. This is the era of the trade's most concentrated asbestos exposure, and exactly the cohort now showing the highest mesothelioma incidence rates among retirees.

1973 — The spray ban

The EPA banned spray-applied asbestos fireproofing in 1973 (following its 1971 designation as a hazardous air pollutant under the Clean Air Act), and OSHA's first asbestos regulations came in 1971. Non-asbestos fireproofing formulations replaced the sprayed asbestos products over the following years.

1980s–today — Post-asbestos era

By the late 1970s and 1980s, sprayed asbestos fireproofing was gone from new construction. Members who entered the trade after that worked under a substantially safer regime. But the disease pipeline from the 1955-1973 sprayed-fireproofing cohort continues. Iron workers who worked those jobs are the population now being diagnosed with mesothelioma and other asbestos-related cancers at extreme rates relative to the general population — and the next two decades will continue to draw heavily from that cohort.