The Future of Occupational Exposure Limits

July 23, 2002
With OSHA's PEL process stalled and voluntary exposure guidelines under attack, it is time to look at other paths for developing scientifically sound exposure limits.

The processes for establishing voluntary occupational exposure limits (OELs) by nonprofit organizations have been legally and scientifically challenged recently. This follows a long history of legal challenges to the standards developed by the Occupational Safety and Health Administration (OSHA). The uncertain future that OEL development faces is a critical concern for safety and health practice in the United States and around the world.

The industrial hygiene profession, as well as other allied environmental and public health disciplines, relies on OELs to assist in our everyday public health professional judgments. Much like physicians, we do not research the toxic effects of every chemical for every situation. Medicines have a range of effects with prescribed procedures for their use. The physician exercises individual judgment in each case, but relies on a scientific body of widely accepted evidence that benefits the many.

How the best scientific level is to be determined in the future is the focus of the OEL development debate. In this article, we will examine several of the processes for establishing and updating OELs, and explore future scenarios with each of them. We must examine our current situation and decide what the optimum OEL process could be and why.

Scenario One: The future extends as it is now, while the OSHA PEL process remains unchanged.

The United States has a very strict process that provides ample checks and balances before an OSHA regulatory limit is promulgated. The advantage is this is an OEL process that is not easily ethically compromised and is transparent, fully participatory and attempts to be fair to all. Finally, yet importantly, it is legally enforceable. In 32 years of practice, OSHA PELs have saved many workers' lives and reduced risk from exposure to chemical and physical agents.

Developing new standards or updating PELs to keep pace with scientific knowledge, however, has been difficult at best. The anti-regulatory trend in American society from the 1980s has largely stalemated updating PEL activities and not permitted most PELs to keep pace with science. The effort to update PELs via adoption of American Conference of Governmental Industrial Hygienists' Threshold Limit Values in the late '80s and early '90s was rebuffed by the left and the right of the political spectrum.

Where does that put us today? Most environmental, health and safety professionals will admit that strict adherence by employers to OSHA's PELs, especially older ones or those that have not kept pace with scientific health risk knowledge, will not protect a company from liability or be able to be argued as a gold standard of occupational health care for its workers. In the emergent knowledge economy, the minimum protection the government specifies is not acceptable for worker protection.

The "standard of care" argument regarding occupational exposure limits is played out frequently in the courts. This is where decisions about OELs will reside more in the future if an OSHA PEL process that stakeholders can accept and trust is not developed. That PEL process must be expedient, efficient, scientifically sound and sufficiently protective. If OSHA PELs are largely judged obsolete and the current voluntary OEL processes are compromised or subject to lawsuit challenges, then courts of law will become the primary venue where public health and medical professionals will argue their OEL cases to jury audiences, the outcome being the de facto standard for the moment.

If the OSHA PEL process is not sufficiently improved, either by providing the resources to make the current process more expedient and scientifically sound or through some other major modification, the result will be greater liability, decreased confidence in the agency to effectively protect workers and less reliance on the agency. This is not a statement about the dedicated OSHA staff and leadership, but more a reflection of what the likely results will be if current trends continue.

Scenario Two: Voluntary nonprofits and guideline-making; the American National Standard Institute (ANSI) Z-37 OEL committee revisited.

Perhaps it is time to revive the long sunsetted ANSI Z-37 committee for OELs and provide it a modern, 21st-century face. ANSI has a long history of developing voluntary consensus standards amongst competitive industries. The possible intent of some of these U.S. national standards is for draft international standards purposes. ANSI has three standards development processes: a committee, a canvass and an accredited organization. Additionally, ANSI has instituted an audit system for its standard-generating secretariats to ensure that processes are operating properly and fairly.

A reconstituted ANSI Z-37 committee, perhaps with subcommittees for individual substances or agents, may provide a means to reach conclusions about OEL guidelines. Given our electronic information age, a committee, or possibly an electronic canvassing process in addition to a committee, may provide the United States with a fair means to develop ANSI OEL guidelines.

Having government agencies or labor or trade organizations adopt these guidelines would be a separate step. ANSI is the only national standards-setting body in the world that is not a government entity. The ANSI process of consensus does not require unanimity. The stakeholder balance and participation required on the committees, canvasses and organization processes may provide a voluntary and fair means to produce OEL guidelines. Government, labor and industry would have a balanced place at the OEL development table. A challenge would be to ensure that minority viewpoints are expressed sufficiently so that one view or perspective does not dominate.

Why ANSI? It has been around for more than 100 years and has the resources and process experience that provide a shield against lawsuits. More importantly, it is a vehicle to achieve consensus on a routine basis (the revision cycle is typically five years) that has been widely accepted in U.S. commerce circles.

The nonprofit organizations that currently establish workplace occupational exposure guidelines may lack the financial resources to do it alone for much longer in the future. The resources to protect against lawsuits and to support a vibrant and open OEL process of an ANSI nature may simply be too great for any one organization to bear.

A shared secretariat among organizations, public and private, may be apropos and provide funding and greater participation. An open question would be whether an agency of the federal government would be able to become a secretariat of an ANSI OEL committee or share it jointly with a nonprofit organization, labor union or some other entity.

Scenario Three: New cooperative U.S. government advisory and guideline structures.

An occupational exposure guideline committee meeting the requirements of the Federal Advisory Committee Act (FACA) could be formed. In 1995, after several years' worth of discussion with many stakeholders, including the American Industrial Hygiene Association's Emergency Response Guidelines and Workplace Environmental Exposure Levels committees, the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances (NAC/AEGL) was formed by the Environmental Protection Agency (EPA). In 2001, the National Academy Press published the first guidelines issued by the committee.

I remember discussions in the early 1990s on developing operating procedures and requirements for the fledgling NAC/AEGL committee. The need to ensure ample stakeholder participation and compliance with FACA requirements so that an efficient and fair process for producing good scientific documents was developed was essential. In my view, the lessons learned in forming this committee and the last several years of its operation could greatly expedite the adoption of a similar process for OELs.

The NAC/AEGL process consists of a team of experts, with support from a contractor who reviews all significant scientific and toxicological data, drafting a document for the committee. The time frames of exposure and definitions of toxic effects are well-defined by the committee. The NAC approves the draft, and it becomes a proposed AEGL. Interim AEGLs are published in the Federal Register for public comment. The NAC/AEGL revises the proposed document based on public comment and sends it to the National Research Council (NRC) subcommittee for AEGLs for final evaluation. The NRC subcommittee provides advice and recommendations, but largely relies on the NAC/AEGL for the accuracy and completeness of the toxicology cited in the AEGL reports. After NRC's final evaluation, the guidelines are published by the National Academy Press.

An advantage of considering the adoption of an FACA OEL committee is that it follows legal precedents established for the government and private sector working together. It would likely not require any modification of statutory mandates of agencies participating in the process or new laws. EPA, the National Institute for Occupational Safety and Health (NIOSH) and the Agency for Toxic Substances and Disease Registry are among some of the government agencies participating in the NAC/AEGL. Funding burdens also could be shared and divided amongst participants.

What form of scientific oversight would be needed for an FACA OEL committee? Would and should the National Academy of Science (NAS) play that role as with the NAC/AEGL committee? Would oversight via another agency such as NIOSH be sufficient or preferable?

My first impression is an FACA OEL committee, adequately funded and with stakeholder participation, could produce valid scientific exposure guidelines for our profession. Additionally, depending on what kind of review and final approval mechanism is adopted (NAS subcommittee or another entity), it could provide a much-needed scientific dispute resolution mechanism for OELs.

Scenario Four: The commanding heights; the rise of a global occupational exposure limit process in a global economy.

Increased global commerce likely will increase the need for consistent occupational exposure limits spanning international borders. Differing national requirements for environmental and occupational health and safety levels affect the cost of producing goods and services. (They really do!)

The scientific risk-reduction argument that human beings exposed to similar agents in the workplace under similar conditions react similarly and, thus, are in need of similar protection will move more to the forefront in the next decade. If we were speaking about nutrition or medicine, we would not argue that a quarter of the dose of penicillin is sufficient for a child in Zambia or that because people in Ethiopia cannot afford food, one-fifth of the caloric input of 2,000 calories per day will suffice. Instead, we would recognize this as an area for development, improvement and a human right needed for these folks.

From where I sit, the same is true for worker exposure across the world. A worker in South Africa, Uzbekistan or the United States is at the same level of risk for a similar duration occupational exposure and should be provided recognition of that fact and protection.

The national sovereignty issues with respect to worker exposure limits will likely fall to better science in the future. Specifically, it will not be possible in the long term to provide two levels of occupational health protection - one for developed nations and another for everyone else. Many progressive companies operating globally already realize this and operate consistently. International OEL regulations or guidelines, and lastly national and international courts, may give rise to de facto standards driving continual OEL improvement. Developing nations are continuing to look to the international community, as well as the United States as their largest export market, for signals of expected occupational health performance that will become global trade expectations or requirements.

How will global occupational health levels be developed? A possibility is that the International Labour Organization, International Standards Organization or the World Health Organization may individually or collectively set up a process for establishing international occupational exposure limits. Advantages could be universal OEL acceptance and recognition, cost and resource sharing for OEL development, improved international scientific cooperation and intergovernmental dialogue on occupational health and safety and trade.

A disadvantage would be practical application. A poor country, as with medicine and nutrition cited at the beginning of this discussion, still would not have the resources and infrastructure to immediately afford the worker protection proposed by international OELs. Recognition of what needs to be done in itself, however, would be an important first step.

Scenario Five: Around the corner, advances in molecular biological science that will affect OEL decision-making.

Due to advances in molecular biology, we are fast approaching the age of individualized nutrition, medicine and, ultimately, environmental exposure risk assessment. An improved process to develop occupational exposure limits must be flexible enough to accommodate advances in molecular biology and toxicology.

In the future, it seems likely we will know more about our individual chemistry before long-term exposure or its impact occurs, and be in a better position to do something about it. What may be a potent carcinogen to you may be of negligible consequence to me based on differences in our genetic makeup.

A case in point is beryllium. Certain individuals who have a predisposition could get a fatal beryllium-related disease at a relatively low exposure level. Others may develop no disease whatsoever, though they are subjected to a significant beryllium exposure that would kill others. It may be possible in the future to detect individuals, before first exposure, who would be at higher health risk from exposure to these materials and eliminate risk entirely. Lifestyle choices and their additive, synergistic or reductive impacts, in combination with occupational agent exposure, will be better known. This new layer of individual molecular biology, apart from the statistical norm, would need to be factored into future OEL processes.


A number of options are available to improve the occupational exposure limit process. None of the ones proposed are exclusive to the others. In fact, some or all of them may emerge as preferred OEL development approaches in one form or another. The key is the recognition and trust required for establishing an OEL process or processes that produce scientifically valuable guidelines and regulations to improve worker health.

About the author: John F. Meagher, CIH, is deputy director of the International Center for Environmental Technology (INTERCET Ltd.) in McLean, Va. Meagher is president of the Metropolitan Washington, D.C., chapter of the World Future Society (MWWFS), an author/contributor to the MWWFS newsletter "Future Takes" and a professional member of the World Future Society. He is the immediate past president of the American Industrial Hygiene Association's Potomac Section (Washington, D.C./Northern Virginia). His views and opinions are his own. He can be reached by e-mail at [email protected], by telephone at (703) 734-1454 or by fax at (703) 734-3241.

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