My colleague Celeste Monforton has just posted a new case study at DefendingScience.org, and it’s worth a read for anyone interested in industry attempts to bury information about products’ potential harmful effects.

The American Conference of Governmental Industrial Hygienists (ACGIH) is a private, not-for-profit, professional organization for practitioners in the field of workplace and environmental health and safety. Since 1946, ACGIH committees have studied substances to which workers are exposed and recommended Threshold Limit Values (TLVs), which are akin to exposure limits.

The reason ACGIH has come under fire is basically that it has filled a void left by OSHA inactivity – and some industries would rather see that void be left empty.

When the Occupational Safety and Health Act was signed in December 1970, it provided the Secretary of Labor with the authority to adopt any “national consensus standards” or “federal standards” for its start-up standards without going through the formal rulemaking process, and set a two-year deadline for the task. By June 1971, OSHA had adopted more than 400 workplace exposure limits for chemical substances, and most of them were based on ACGIH TLVs. While some public health advocates criticized the move, asserting that ACGIH’s process was excessively influenced by industry-employed industrial hygienists, it probably would have been difficult to set exposure limits for so many chemicals through any other mechanism.

In 1989, OSHA once again tried to use ACGIH’s extensive and ongoing TLV work to update exposure limits for more than 400 substances as part of its final air contaminants rule. This time, they weren’t so successful. Monforton writes:

Despite the Department of Labor’s satisfaction with the rule, both labor and industry groups challenged it in the U.S. Court of Appeals, with one side arguing the rules did not protect workers enough, and the other claiming the streamlined process was illegal. The Court was convinced by the arguments and in July 1992 vacated OSHA’s air contaminants rule. The Court instructed the agency of its obligation to make a risk and feasibility finding for each of the 428 substances, something that OSHA had not done in the rule. As a result of this court decision and OSHA’s unwillingness to engage in a follow-up rulemaking, nearly all of the OSHA exposure limits on the books still date back to 1968.

Although this attempt to adopt updated ACGIH TLVs ultimately failed, OSHA did succeed in making TLV information available to workers. OSHA’s 1983 Hazard Communication (HazCom) rule requires that chemical manufacturers make available Material Safety Data Sheets on the chemicals they produce. These MSDSs must include any OSHA permissible exposure limit and ACGIH TLV on the substance, and must state whether the chemical is listed in the National Toxicology Program’s Report on Carcinogens or is designated a potential carcinogen by the International Agency for Research on Cancer.

For nearly 20 years, industry groups did not seem to have any problem with the inclusion of ACGIH TLVs on MSDSs. Then, in 2000, companies that use and manufacture substances for which the ACGIH was developing TLVs began challenging ACGIH and the Department of Labor. In courts and in House committee hearings, industry attorneys advocated for removing TLVs from MSDSs – and, in some cases, for stopping ACGIH from issuing certain TLVs altogether.

The presence of ACGIH TLVs on MSDSs does not constitute any kind of regulation – employers are under no obligation to reduce worker exposures to the TLV level. The companies’ problem, then, must be that workers may want employers to reduce exposure to the level recommended by the ACGIH. They’d evidently rather spend their money suing ACGIH, which does not have such deep pockets and has had to set up a legal defense fund, than following its recommendations.

To learn about the substances companies are fighting to keep TLV-free, the Congressman who declared war on the ACGIH, and some out-on-a-limb legal arguments, read the whole case study.

Liz Borkowski works for the Project on Scientific Knowledge and Public Policy at George Washington University’s School of Public Health and Health Services.