Corporate influence on threshold limit values

Our plain-English summary of Corporate influence on threshold limit values, by B.I. Castleman, G.E. Ziem (American Journal of Industrial Medicine, 1988).

The study

• Authors: B.I. Castleman, G.E. Ziem
• Journal: American Journal of Industrial Medicine
• Published: 1988;13(5):531-59
• Type of article: Historical article
• Cited by: 119 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 000198).

Abstract

Investigations into the historical development of specific Threshold Limit Values (TLVs) for many substances have revealed serious shortcomings in the process followed by the American Conference of Governmental Industrial Hygienists. Unpublished corporate communications were important in developing TLVs for 104 substances; for 15 of these, the TLV documentation was based solely on such information. Efforts to obtain written copies of this unpublished material were mostly unsuccessful. Case studies on the TLV Committee's handling of lead and seven carcinogens illustrate various aspects of corporate influence and interaction with the committee. Corporate representatives listed officially as "consultants" since 1970 were given primary responsibility for developing TLVs on proprietary chemicals of the companies that employed them (Dow, DuPont). It is concluded that an ongoing international effort is needed to develop scientifically based guidelines to replace the TLVs in a climate of openness and without manipulation by vested interests.

In plain English

This 1988 article was a historical review of how the American Conference of Governmental Industrial Hygienists (ACGIH) set Threshold Limit Values (TLVs), which are workplace exposure limits. The authors reviewed the 1986 TLV Documentation for all chemical substances, tried to obtain the unpublished company material it cited, and examined old committee files. They judged that unpublished corporate communications were important for 89 substances and were the only basis for 15 more. That made 104 in all, over one sixth of the fewer than 600 substances listed. They found written copies of far less than half of this material. Committee minutes from 1972 to 1976 showed Dow and DuPont representatives taking primary responsibility for TLVs on their own companies' products. For asbestos, a 1968 proposal to tightly control crocidolite was dropped. ACGIH adopted 5 f/cc in 1974, two years after OSHA set that level, and in 1980 set 2 f/cc for chrysotile with lower limits for crocidolite and amosite. The authors called this a major conflict of interest and proposed an international effort to replace the TLVs. They noted that their judgements were subjective.

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: Historical and documentary review of the ACGIH TLV-setting process, with case studies of lead and several carcinogens (including asbestos)
• Who was studied: The chemical substances (fewer than 600) listed in the 1986 ACGIH TLV Documentation, plus historic TLV committee files at NIOSH and material requested from 17 corporations
• Exposure: Reliance on unpublished corporate communications and industry participation in setting TLVs. The asbestos case study covered limits for asbestos generally and for chrysotile, crocidolite and amosite.
• Main results:
  • For 89 substances, the 1986 Documentation placed important reliance on unpublished corporate communications.
  • 15 further substances were assigned TLVs based only on unpublished corporate studies and reports.
  • The authors located written copies of far less than half of this unpublished corporate material.
  • Of 17 corporations asked for the documentation they had provided, nine sent old documentation or commented on their work.
  • From 1972 to 1976, corporate representatives (from Dow and DuPont) bore primary responsibility for TLV documentation on their own companies' major products.
  • A 1968 proposal to stringently control exposure to crocidolite asbestos was dropped before the 1968 TLV book was published.
  • ACGIH adopted a TLV of 5 f/cc for asbestos in 1974, two years after OSHA had set a standard at that level.
  • The authors judged that industry members documenting TLVs for their own companies' products was a major conflict of interest.
• The authors' conclusion: The authors concluded that an international effort should be mounted to gradually replace the TLVs.
• Limitations the authors state:
  • Deciding whether unpublished information was important in setting a TLV was a matter of the authors' judgement.
  • The authors expected that other experts doing the same review would produce slightly different lists.
  • ACGIH refused access to the TLV committee minutes for the last 10 years.
  • Most of the unpublished corporate communications could not be obtained in written form.

Topics

Medical terms in this study, explained in our Lexicon: Threshold Limit Value (TLV).

Related studies

• The origin and development of the asbestos Threshold Limit Value: scientific indifference and corporate influence — D.S. Egilman, A.A. Reinert (1995)
• The role of threshold limit values in U.S. air pollution policy — J.C. Robinson, D.G. Paxman (1992)
• The limits of thresholds: silica and the politics of science, 1935 to 1990 — G. Markowitz, D. Rosner (1995)
• Time to reconsider TLVs — L. Djerassi (1988)
• Present threshold limit value in the U.S.A. for asbestos dust: a critique — E.L. Schall (1965)
• Talc, Asbestos, and Epidemiology: Corporate Influence and Scientific Incognizance — T.H. Tran, J.E. Steffen, et al. (2019)

Browse more research in American Journal of Industrial Medicine, or return to medical research.