The Inside Story
Vinyl Chloride: Dissolving Finger Bones
From 1953 to 1972, the Manufacturing Chemists Association Chemical Safety Data Sheet for vinyl chloride recommended 500 parts per million (ppm) as an acceptable average exposure level over the course of a workday. Yet by 1959, industry scientists had compelling evidence that this level of exposure was not safe, and that vinyl chloride was injuring workers at levels well below the 500 ppm daily average. One scientist was unusually candid in his assessment of the risk:
Industry sponsored animal tests at that time detected "liver injury" after inhalation of vinyl chloride for just six months at 100 ppm, 5 times less than the acceptable daily level for workers. (view entire document) After conversations with Dow scientists who were not able to find a dose of vinyl chloride in animals that did not cause harm, a Union Carbide memo reported that "vinyl chloride monomer is more toxic than has been believed." (view entire document)
But the industry did not respond. Even after Dow researchers published a paper in 1961 reporting that vinyl chloride was toxic at levels well below 500 ppm, companies did nothing to warn workers that vinyl chloride was hazardous, or to lower allowable exposure levels below 500 ppm. Dow apparently adopted a 50 ppm standard in 1961. At the time there were no legally enforceable workplace chemical exposure limits.
By the mid-1960s the first waves of injured workers were appearing. There were reports of acroosteolysis (AOL), referred to in industry documents as "the hand disease," an insidious and debilitating condition that, in the most extreme cases, was manifested by degeneration of the bones in the tips of the fingers. Workers' finger bones were dissolving, but rather than opening an investigation of the issue, the industry opted for evasive medical exams, and a gag on all dissemination to workers of information relevant to the situation.
A 1964 internal memo from B.F. Goodrich is instructive:
Continuing on, the memo states:
As evidence of the disintegrating hand problem mounted throughout the 1960s in Europe and the United States, the industry attempted to directly influence the science. A 1966 internal Monsanto memo recounts B. F. Goodrich's reaction to the mere possibility of a publication describing the diseases in the peer-reviewed literature:
That particular intervention was unsuccessful, but not to be deterred, the Monsanto memo further reports that:
A 1967 article by B.F. Goodrich scientists in the Journal of the American Medical Association finally did report the "basic characteristics of this disease." But in line with the overall strategy of downplaying the significance of the findings in relation to vinyl chloride, the authors state that: "The specific causes are unknown" (view entire document) and that the condition is not particularly serious: "We have observed no serious disability in any of these cases." (view entire document)
But the industry knew otherwise. A November 1964 internal Goodrich memo notes that the company has observed "bone resorption" in the tips of the fingers of it workers, and that "In some cases this is quite marked." A January 1966 memo from Monsanto recounts a conversation with a B.F. Goodrich Corporate Vice President who reported that AOL was occurring in workers not directly involved in cleaning the vinyl chloride polymerization reactors, or so called "kettles":
In June 1968, B. F. Goodrich was still guarding information on scores of cases of the disease at its vinyl chloride and polyvinyl chloride facilities as "confidential" and "not to be disseminated." (view entire document) A Goodrich memo at the time reports 49 cases and then goes on to say:
Widespread AOL across the industry was a powerful indication that vinyl chloride was far more toxic than previously believed, and affected workers through systemic action. But the industry ignored the warning signs. On November 24, 1969, the MCA Plastics Committee resolved that it would not accept further proposals for additional research into the causes of acroosteolysis. (view entire document)
Shutting down investigations, however, could not stop the inevitable progress of the disease among vinyl chloride workers. "The hand disease" was a warning of much worse afflictions to come.
last updated: march.27.2009