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Science In TSCA Reform

August 12, 2013 | A version of this story appeared in Volume 91, Issue 32

This guest editorial is by Rainer Lohmann, Heather M. Stapleton, and Ronald A. Hites. Lohmann is a professor of oceanography at the University of Rhode Island. Stapleton is an associate professor of environmental chemistry at Duke University. Hites is a distinguished professor of public and environmental affairs and of chemistry at Indiana University, Bloomington.

The Toxic Substances Control Act (TSCA) of 1976 tasks the Environmental Protection Agency with regulating the manufacture and sale of chemicals in the U.S. to protect the public from risks to health and the environment. When Congress passed TSCA 37 years ago, the chemical industry listed all the substances they had in production at that time and those they anticipated producing. The list of more than 60,000 substances became the TSCA Inventory. TSCA assumed that these compounds were safe until proven otherwise, and few tests of their effects on human health or natural ecosystems were carried out. This assumption was fundamentally unsound.

Legislation now before the Senate, called the Chemical Safety Improvement Act of 2013 (CSIA), makes some improvements over TSCA (see page 24). CSIA would require EPA to classify chemicals as high or low priority for safety assessment and to evaluate the safety of high-priority chemicals entering the marketplace and those already in commerce. High-priority chemicals are those “that are highly toxic and that people could be highly exposed to, … [that could] pose a high hazard, or to which there is widespread exposure” (C&EN, June 10, page 22). Presumably, if EPA finds a high-priority chemical unsafe because a safety assessment determines that it poses an unreasonable risk, EPA can ban or otherwise regulate it.

These changes are welcome. However, we think the U.S. can do better by emphasizing science. High-throughput in vitro screening assays for evaluating many toxic end points should be developed and considered for use in the mandatory testing of new chemicals. CSIA should take into account that the potential effects of chemicals must be evaluated over long periods of time, particularly for sensitive populations. CSIA should recognize these challenges and be less proscriptive and more holistic. And it should be harmonized with chemical regulations in Europe, Japan, Canada, and Australia; the U.S. does not need to reinvent the wheel.

TSCA and CSIA are designed to evaluate chemicals independently, one chemical at a time. Yet humans and the environment are often exposed to complex mixtures. Studies have shown that a cocktail of many individual compounds all present at their no-effect levels can still result in significant adverse effects. In addition, because many chemical manufacturers sell their products as mixtures, safety evaluations should be conducted not only on individual chemicals but also on the mixtures as marketed.

Neither TSCA nor CSIA limits the period during which a chemical and the associated data can be considered proprietary. This should change. Chemical companies should have only a few years during which information they submit to EPA will be considered confidential. After this time, information should be publicly available, including site-specific production data. Without information on chemical identity, it becomes almost impossible for scientists to identify these chemicals in the environment and to assess human exposure levels. And because research on many chemicals is hindered by a lack of authentic standards, samples of any chemical substance produced or imported into the U.S. should be archived in a national repository funded by the chemical industry. These changes will open a dialogue among industry, academia, and nongovernmental organizations to identify problem substances and to assess safer alternatives.

TSCA reform is needed, and the scientific community must be at the table as Congress rewrites TSCA. With scientific input, the U.S. can learn from past mistakes and benefit from decades of research on the environmental fates and effects of chemicals. Many of us have dedicated our professional lives to better understanding chemicals’ environmental concentrations, properties, transport, fates, and effects. We need to get involved through our scientific organizations and our representatives in Congress.

Rainer Lohmann
Heather M. Stapleton
Ronald A. Hites

Views expressed on this page are those of the author and not necessarily those of ACS.


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