WHAT IS REGULATORY TOXICOLOGY?
Regulatory toxicology is a subfield of regulatory science, which addresses the intersection of science with regulation, namely how the science of toxicology is developed, evaluated, and applied in regulatory decision-making. Toxicology is one of the most common fields of scientific knowledge utilized in regulatory science, as regulatory agencies often are required to identify and quantify the health risks of the products and activities they seek to regulate. Regulatory toxicology, which must straddle traditional scientific methodologies with the public policy world of regulation, strains to adhere to the standards of good toxicological science while also providing relevant inputs to decision-making, which often asks questions that science cannot answer completely or with any certainty. It is the tension between these two different worlds of science and policy that raise many of the most important and challenging issues in regulatory toxicology, many of which are addressed in this chapter.
Over the past 50 years, the field of regulatory toxicology has grown enormously as the intersection between regulation and toxicology has expanded dramatically. With the enactment of a series of environmental, health, and safety laws in the United States, Europe, and elsewhere in the 1970s and 1980s, regulatory agencies increasingly rely on toxicological science to identify potential hazards, prioritize chemicals and other potentially toxic substances, and provide the data used for assessing and managing risk. Regulators are not merely consumers of toxicological studies but also help shape toxicology science in important ways. Regulatory programs have provided a major impetus for improvements in toxicology methods, and they have stimulated a demand for toxicology studies that meet various regulatory requirements. Some programs, such as regulatory programs for licensing drugs, devices, food additives, and pesticides, explicitly demand toxicology studies as a condition for marketing products. Other statutory and regulatory requirements, such as the recent program requiring agencies to screen chemicals for their endocrine disruptor capability, or agencies to evaluate the safety of new nanotechnology applications, are a major driver for the development of new types of toxicological assays.
Regulatory agencies have exercised important influence over the design and conduct of toxicology studies. For example, the United States Environmental Protection Agency (EPA) is empowered by the Toxic Substances Control Act (TSCA) to promulgate standards for different types of toxicology (and other scientific) investigations. Likewise, the U.S. Food and Drug Administration (FDA) has long issued guidelines for laboratory studies submitted in support of food additives and drugs. Both agencies have adopted requirements governing laboratory operations and practice, known as Good Laboratories Practice (GLP). Communication between government officials and laboratory scientists flows in both directions. Government testing standards are influenced strongly by the prevailing consensus among toxicologists, many of whom work in regulatory agencies. Similar standards have been established at the international level through the Organization for Economic Co-operation and Development (OECD).
THE SCIENCE/POLICY INTERFACE IN REGULATORY TOXICOLOGY
There are critical differences between the objectives and ...