A workshop titled "Using Sentinel Species Data to Address the Potential Human Health Effects of Chemicals in the Environment," sponsored by the U.S. Army Center for Environmental Health Research, the National Center for Environmental Assessment of the EPA, and the Agency for Toxic Substances and Disease Registry, was held to consider the use of sentinel and surrogate animal species data for evaluating the potential human health effects of chemicals in the environment. The workshop took a broad view of the sentinel species concept, and included mammalian and nonmammalian species, companion animals, food animals, fish, amphibians, and other wildlife. Sentinel species data included observations of wild animals in field situations as well as experimental animal data. Workshop participants identified potential applications for sentinel species data derived from monitoring programs or serendipitous observations and explored the potential use of such information in human health hazard and risk assessments and for evaluating causes or mechanisms of effect. Although it is unlikely that sentinel species data will be used as the sole determinative factor in evaluating human health concerns, such data can be useful as for additional weight of evidence in a risk assessment, for providing early warning of situations requiring further study, or for monitoring the course of remedial activities. Attention was given to the factors impeding the application of sentinel species approaches and their acceptance in the scientific and regulatory communities. Workshop participants identified a number of critical research needs and opportunities for interagency collaboration that could help advance the use of sentinel species approaches.

Public concern for animal welfare has been expressed through legislative control of animal use for experimental purposes since the first legislation was introduced in 1876 in the United Kingdom. Legislative control of animal use has been introduced in virtually every developed country, with major initiatives in Europe (1986) and the United States (1966 and 1985). Advances in scientific thinking resulted in the development of the concept of the three Rs—refinement, reduction, and replacement—by Russell and Burch in 1959. The field has expanded substantially since, with specialist scientific journals dedicated to alternatives, World Congresses organized to discuss the scientific and philosophical issues, and European and U.S. validation organizations being launched. Current scientific attention is focused on validation of alternative methods. The underlying scientific principles of chemical toxicity are complicated and insufficiently understood for alternative methods for all toxicity endpoints of importance in protecting human health to be available. Important lessons have been learned about how to validate methods, including the need to have prediction models available before the validation is undertaken, the need to understand the variability of the animal-based data which is to be used as the validation standard, and the need to have well-managed validation programs. Future progress will depend on the development of novel methods, which can now be validated through international collaborative efforts.

The OECD Workshop, held on 22-24 January 1996 in Solna, Sweden, was an important first step to achieve internationally harmonized principles and criteria for the validation and acceptance of alternative toxicological test methods. There was broad participation from all interested parties, including over 50 representatives from animal welfare organizations, government regulatory and research agencies, industry and academia. The Workshop used existing work on criteria from many organizations, including recent publications from CAAT, ECVAM and ICCVAM. The Workshop participants a) reached consensus on harmonized principles and criteria for the validation and acceptance of toxicological test methods, with an emphasis on alternative tests; b) developed guidance for Validation procedures; c) developed general principles for testing strategies and tiered testing schemes that could incorporate alternative tests; and d) developed draft tiered testing schemes for dermal and ocular irritation that will be proposed in revised OECD testing guidelines. The OECD Workshop report will form the basis for an OECD Guidance Document that will describe the validation process in greater detail.The proposals and recommendations of the OECD Workshop were discussed during a World Congress Workshop in Utrecht. This contribution presents a synopsis of this Workshop.

An international workshop on harmonization of validation and acceptance criteria for alternative toxicological test methods was convened by the Test Guidelines Programme of the Organisation for Economic Cooperation and Development (OECD) on 22-24 January 1996, in Solna, Sweden. The objective for the first of the three subjects discussed was to reach consensus on harmonized principles and criteria for the validation and acceptance of any new or revised test methods, including both animal and nonanimal methods. Background references included recent documents from the European Center for Validation of Alternative Methods (ECVAM), and the US Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM). Specific criteria were developed that new and revised test methods should meet in order to be considered as having undergone adequate validation or to be considered acceptable for regulatory use. Recommendations were developed for other considerations, including: the need for flexibility, validation of test methods in a battery approach, validation of adjunct tests, parallel submission of data from existing and new methods, and acceptance of patented test methods. Internationally harmonized criteria for validation and regulatory acceptance are expected to facilitate worldwide review and adoption of improved toxicological test methods that will support enhanced protection of human health and the environment, and benefit animal welfare by the replacement, reduction, and refinement of animal use.