If you were ever wondering about why asbestos was used – the following passage shows how useful it could be.

Read all about how Asbestos became such a commonly used material in “Asbestos & Fire”.

This trend had three effects on asbestos mining. First, it made previously marginal deposits of short fibers economically attractive, with the result that old deposits and their tailings could be reworked into the shorter grades of fiber; and new mines opened to exploit deposits that had not previously been considered worth the trouble. New mines were opened overseas in Morocco, Egypt, China, and Australia and in Maine and California in the United States.43 Even Alaskan “mountain leather,” or paligorskite, a dark and usually soggy asbestiform mineral resembling untanned hide when dry and previously thought unworkable, was the subject of experiments in the making of filters and acoustical and shock insulation. Alaskan tremolite had reportedly been used by the U.S. government during the war as a filtering agent for blood plasma.44

Second, demand encouraged the exploration of new uses for the material since in the lower grades it was no longer as expensive relative to other materials as it had been in the 1920s. It was already in use as a filler for plastics, including so-called “Ebonized asbestos,” in electrical insulation applications such as switchboards in the 1930s; and additional uses for asbestos combined with rubber or phenolic compounds (plastics) were added almost every year during the late 1940s, 1950s, and 1960s. Ebonized asbestos was approved by the U.S. Navy Bureau of Engineering in the 1930s and was widely used in industrial electrical installations as well. The material reportedly would withstand temperatures as high as 2,800 degrees Fahrenheit but could be worked with carpenter’s tools, unlike its predecessors in the same applications, marble and mica.45 It also weighed considerably less than either.

Some of the new uses for the mineral were relatively glamorous-literally space age, such as the phenolic-impregnated asbestos flame shield adopted by the U.S. Army for the Pershing missile and the simpler asbestos insulation used in backyard rocketry by teenagers. The product manager of RaybestosManhattan described the new phenolics with evident patriotic pride in Plastics World in 1958

A special family of asbestos-reinforced plastics materials has been developed here at Raybestos-Manhattan for specific use in missilry [sic]. These materials have gone into missile fins and shrouds, rocket launcher bodies and tubes, rocket throats and cones, silver traps for propellant barriers and rocket tailcap insulators, to mention a few.

Titan, Polaris, Sidewinder and Terrier missiles are using laminated or molded asbestos as heat insulation shields, tubing and heat diverters. The Navy’s Vanguard is equipped with an asbestos-phenolic nose cone intended to streamline the rocket and to insulated the enclosed satellite from friction-generated heat in high-speed upward flight as well as to protect the rocket itself from the ram effect of aerodynamic loading.

These parts for missiles feature high-strength to small-weight ratio (an important fact in rocketry), an extremely high modulus of elasticity at low and elevated temperatures, resistance to blistering, delamination and erosion when subjected to high temperatures and thermal shock.

In 1964, the year before the New York Academy of Sciences published its volume of papers on asbestos, two especially flashy new uses for asbestos were announced. One was “the extension skirt for the second-stage engine of thel Gemini 4 space rocket (which was made of asbestos felt impregnated with a specially developed phenolic resin;” the other was powdered asbestos “use the reinforcing agent in the joining of the various reinforced plastic parts of the Chevrolet Corvette automobile body. 46 Other uses of the period were more pedestrian: heat-resistant ball valves for oil and gas pipes, asbestos-nitrile rubber gaskets used in off-road equipment and compressors, asbestos plastic bearing materials, and fire-curtain walls for railroad engine roundhouses.47

Third, the marketability of floaters and refuse encouraged mining and manufacturing companies to install more effective dust-removal systems. Efforts to control dust for health reasons in asbestos factories and mills had begun during the 1920s; and after publication of a U.S. Public Health Service standard of 5 million particles per cubic foot of air in 1938, the American Conference of Governmental Industrial Hygienists and many states adopted this figure by 1950 as one below which “new cases of asbestosis would not appear,” as the health service expressed it.45 Predictably, industrial firms responded grudgingly to this standard, much as coal mines did when measures to reduce black lung were introduced and as cotton mills were to do later when required to reduce levels of the airborne cotton trash that causes byssinosis.49 Between the reluctance of

spend money on dust-control equipment in a period of slack business, the parlous condition of state labor department inspection budgets during the Depression, and concerns by unions and others dependent on the income stream from what manufacturing jobs had survived the downturn of 1929-39, dust-control standards in many U.S. industries were not often vigorously enforced in the decade immediately preceding World War II.

Dust-control equipment originally installed to protect the health of workers, however, began to seem more economically reasonable when it collected a product that could be sold at a profit; and measures were taken in most mining and manufacturing operations that handled raw asbestos to recover as much of the dust as was possible with the technology of the period. Even good dust collection technology still left a great deal of dust on floors, ceilings, walls, machinery, and other surfaces, a problem that had still not been solved by the mid-1980s. Nevertheless, companies that could afford the outlay during the


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