The responsibility of a pipe fitter – also sometimes known as a steam fitter – is to install, inspect, maintain and repair climate control systems that operate with boilers, radiators and oil burners. These tasks may also extend to such steam systems used in commercial laundries and kitchens. Pipe fitters repair pipes and pipe coverings, rethread such pipes, and do maintenance and repair work on valves. In addition, pipe fitters were frequently employed in shipyards, and sea-going vessels often contain large amounts of asbestos insulation throughout their construction – particularly in the engine room, where most pipe-fitting tasks are carried out.
Asbestos exposure is a very real danger when working with such systems, as asbestos insulation was, until the early 1980s, used anywhere that heat or flame was a danger.
“ACM” means asbestos containing material. Under the federal “Grace Rule” (named for asbestos manufacturer W.R. Grace & Company), a product may contain up to 1% asbestos and still be considered “asbestos free”.
Monokote® was a sprayed-on type of ACM insulation used for lagging steam pipes aboard steamships as well as commercial and residential buildings. While manufacturer W.R. Grace, Inc. claimed the substance was “asbestos-free,” the truth is that up until the mid 1970s, the asbestos content of Monokote was as much as 12%. According to the “Grace Rule,” the current version of this substance – Monokote MK6 may still contain up to 1% asbestos.
Possibly one of the worst asbestos offenders in the history of such litigation, W.R. Grace & Company was also the manufacturer of another so-called “asbestos free” product, marketed as Zonolite™. The primary (and according to Grace management, the only) ingredient was vermiculite, which is a form of clay that expands when exposed to heat. Highly absorbent, this substance is also found in clumping cat litter. The problem is that most of the company’s vermiculite came from its operation in Libby, Montana, where a great deal of asbestos was mined. As a result, W.R. Grace Inc. vermiculite products were usually contaminated with asbestos fibers.
One other ACM building product likely to be encountered by steam and pipe fitters is called “asbestos cement.” AC paneling is essentially a type of wallboard made from thin slabs of cement that has been reinforced with asbestos fibers. These asbestos fibers, which may be of either the serpentine or the amphibole variety, may make up as much as 10% of the material.
Serpentine vs. Amphibole
In terms of detrimental health effects, these two varieties of asbestos differ only in terms of degree. Serpentine asbestos includes chrysotile, and was perhaps the most commonly-used form of asbestos. Also known as “white” asbestos, serpentine fibers are softer and curled in shape.
Under a microscope, amphibole fibers have a spear or needle-like appearance. They are quite rigid and can do a great deal of internal damage to the lungs in a relatively short time – particularly when highly concentrated. The most common forms of these are crocidolite, or “blue” asbestos, and amosite, or “brown” asbestos. The latter contains iron oxide (hence its brown color), and is exceptionally resistant to acids and other caustic chemicals, and were therefore often used in chemical plants.
A study of cement workers in Louisiana conducted in 1987 showed that workers exposed to amphiboles suffered a slightly higher rate of the rare form of asbestos cancer known as mesothelioma – 29 per one thousand – than those exposed to serpentine, whose malignant mesothelioma rate was 22 per one thousand. Beyond this small difference, both types have been shown to be a major factor in the development of respiratory disease.