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Disclosing Chemical Hazards to Reduce Workplace Health and Safety Risks

A National Institute for Occupational Safety and Health survey conducted in 1972 found that “approximately 25 million U.S. workers, or one in four, [were] potentially exposed to one or more of...nearly 8000 hazards” and that 40 to 50 million Americans, amounting to over 20 percent of the population, may have been exposed to hazardous chemicals. Often neither employers nor employees were aware of the presence of hazardous substances in the workplace. Lack of knowledge hampered diagnosis and treatment when workers became ill from chemical exposure.


Responding to this problem in the 1970s, unions, public interest groups, and state legislators promoted the idea of a workers’ “right-to-know” about chemical exposures and associated dangers. The federal Occupational Safety and Health Administration (OSHA) had issued standards specifying limits on levels of benzene, lead, and some other extremely toxic chemicals, but promulgating separate standards for hundreds of thousands of hazardous chemical products seemed impractical. Instead, labor and other public interest groups pressed for an approach based on greater transparency. In 1981, the Carter administration proposed a disclosure requirement that would have applied “to virtually all businesses that used hazardous substances.” The Reagan administration, however, proved more hostile to greater transparency, prompting unions to shift their lobbying efforts from the federal to the state level. As a result, many states—including New Jersey, Pennsylvania, and Illinois—adopted their own right-to-know laws by the mid 1980s. At that point, industry groups supported adoption of a uniform federal standard as an alternative to variable state right-to-know laws, and the federal hazard communication standard was adopted in 1983. The Reagan administration narrowed the initial rule to require only manufacturing firms to disclose chemical information. OSHA argued that manufacturing amounted to 32 percent of total employment and accounted for more than 50 percent of illnesses caused by exposure to chemicals.


The requirement created a two-part chain of disclosure. First, chemical manufacturers and importers evaluated the hazardousness of the substances they produced or imported and disclosed that information to employers who purchased their products. Second, employers made the information available to workers who handled hazardous substances. Manufacturers and importers attached to containers of hazardous chemicals descriptive labels listing the identity of the substance, a hazard warning, and the company’s name and address. Chemical manufacturers also provided employers with material safety data sheets that contained more extensive information about chemical identity, physical and chemical characteristics, physical and health hazards, precautions, and emergency measures. Finally, in plants where workers were exposed to hazardous substances, employers were required to provide the data sheets and train employees in accessing chemical information, protecting themselves from risk, and responding to emergencies.


Many labor and consumer groups were unsatisfied with the disclosure system’s limited scope, however. Soon after its approval, United Steelworkers of America, AFL-CIO-CLC, and Public Citizen attacked the standard’s narrow scope and preemption of sometimes stronger state right-to-know laws. Rejecting the Reagan administration’s rationale for limiting disclosure to manufacturing firms, the U.S. Court of Appeals in 1985 directed the secretary of labor to extend disclosure to all sectors. In 1987, a new court ruling confirmed that all industries where employees were potentially exposed to hazardous chemicals had to comply with the disclosure requirements. By 2004, OSHA estimated that over 30 million American workers were exposed to hazardous chemicals in their workplaces and that the hazardous chemical reporting system affected around 3 million workplaces and 650,000 chemical substances.


Over time, chemical manufacturers improved their disclosure of chemical hazards. Manufacturers responded to employers’ requests for additional chemical information and sought to limit their potential liability for willfully hiding information on dangerous chemicals. A 1992 study by the GAO found that 56 percent of surveyed employers reported “great” or “very great” improvement in the availability of information, and 30 percent said they substituted less-hazardous chemicals because of the information they received.


Material safety data sheets became a routine method of conveying product information about both hazardous and non hazardous chemicals. Many firms now post on the Internet data sheets for all their products, and a number of Web sites offer searchable databases. Some manufacturers use disclosure as a competitive tool, offering their customers more information than OSHA requires, including guidance on how to comply with disclosure requirements, training materials, and experts to assist customers.


Manufacturers and employers also improved the quality of the reported information. Responding to criticism about the quality of material safety data sheets, the Chemical Manufacturers Association convened a committee to develop guidelines for the preparation of such sheets. Their effort contributed to the adoption of a voluntary industry standard for these sheets in 1993, which was subsequently endorsed by OSHA. Despite progress of this kind and several OSHA guidelines aimed at improving disclosure, chemical hazard disclosure ranked second in the list of the ten most violated OSHA standards in 2005, accounting for over 8 percent of all violations.


The extent to which workers comprehend disclosed information about chemical hazards and take protective measures in response also remains unclear. Surveys have shown that employees are generally able to understand only around 60 percent of information in chemical data sheets, with more-educated workers doing significantly better than those who are less educated. Even in cases where workers understand safety information, surveys suggest that they often make only limited use of it. It is also interesting to note that all documented cases suggesting that training and information disclosure have a positive impact on workers’ behavior involve unionized firms where labor organizations may have played an intermediary training or information-disseminating role.


At the international level, OSHA played an important role in the development of an international format for chemical classification and labeling, leading to the United Nations’ adoption of a globally harmonized standard in 2002. In 2012, OSHA modified its hazard communication standard to adopt the UN's harmonized standard, which is already implemented in 72 countries. The harmonized standard includes more specific criteria for the classification of health and physical hazards as well as for the classification of mixtures. These changes should ensure that evaluations of hazardous effects are consistent across manufacturers. Under the new standard, labels include a harmonized signal word, a pictogram, a hazard statement and a precautionary statement. Finally, the new material safety data sheets have a consistent 16-section format to make the information readily accessible for employers, workers and health professionals. Chemicals crossing borders will carry consistent information to improve risk communication and safety across countries. The timeline for implementing the changes introduced by the harmonized standard started in December 2013 and will end in June 2016.  


Updated May 2016


This case study is drawn from Full Disclosure, Fung, Graham and Weil, 2007.


Occupational Safety and Health Administration


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