Fiber Glass Chemistry and Technology

Our plain-English summary of Fiber Glass Chemistry and Technology, by C.P. McCord (1967).

The study

• Author: C.P. McCord
• Published: Journal of Occupational Medicine, Volume 9 No7. July 1967.
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library. The article is still under copyright, so we describe it here rather than post it.

In plain English

This 1967 article from the Institute of Industrial Health at the University of Michigan was a descriptive overview of fibrous glass. It was not a research study, and it did not discuss asbestos. The author explained that fiber glass is generally classed as a borosilicate glass because it contains boric oxide. It was first produced commercially in the early 1930s, and the fibers are almost always coated with binders, lubricants, sizes and coupling agents. The article listed raw materials and binder chemicals, described only the wool manufacturing process, and listed typical products. The short section on biologic effects included the following statements. Skin irritation occurs among fiber glass makers, particularly new workers, but is not remarkable. No free silica occurs in the glass fibers. Animal experiments with fiber glass particles placed in the respiratory tract failed to provoke a condition whose name is garbled in the text. No clinical cases of lung cancer had been traced to fiber glass. Exposure to possibly harmful ancillary chemicals was not covered. Much of this section is damaged in the scanned text.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Descriptive overview article on fibrous glass chemistry, manufacture and uses; no original study data, methods or statistics
• Who was studied: The author studied no people or animals. The article describes fibrous glass and the manufacture of wool-type fiber glass products.
• Exposure: Fibrous glass (wool and textile fibers), generally a borosilicate glass containing boric oxide, coated with binders such as phenol formaldehyde and urea formaldehyde resins. Fiber diameters are stated as .00012 in. to .00400 in. (printed '00400 in.', confirmed by the spelled-out 'four-hundred-one-hundred-thousandths'), compared with human hair at .00066 in. to .00715 in.
• Main results:
  • Fibrous glass was first produced for the commercial market in the early 1930s
  • The smallest fiber diameter given was .00012 inch
  • Among fiber glass makers, particularly new workers who are most exposed, skin irritation occurs but is described as not remarkable
  • Free silica is a raw material, but the author stated that no free silica occurs in the glass fibers or the final products
  • In animal experiments, putting fiber glass particles into the respiratory tract failed to provoke a lung condition. Its name is garbled in the text, appearing only as 'pnclll:oco-'.
  • The author wrote that no clinical cases of lung cancer had been traced to fiber glass as the source
  • Some chemicals used alongside fiber glass production may possess some harmful properties. Examples given are partially polymerized phenol formaldehyde, urea formaldehyde and epoxy resins, fluorides and trichlorethylene.
• The authors' conclusion: In a badly damaged passage, the author appears to have stated that fiber glass is not a known carcinogen and that its biologic effects amount to superficial and transitory irritation
• Limitations the authors state:
  • The author stated that fiber glass makers' exposures to the potentially harmful ancillary chemicals were not considered in the article
  • Only the wool production process was discussed, not the textile yarn process

Topics

Medical terms in this study, explained in our Lexicon: Lung Cancer.

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