Precaution, Scientific Development and Scientific Uncertainty under the WTO Agreement on Sanitary and Phytosanitary Measures

The World Trade Organization (WTO) Appellate Body has noted that the precautionary principle will be relevant to the interpretation of the WTO Agreement on Sanitary and Phytosanitary Measures in various ways, although the Appellate Body has declined to determine the status of the precautionary principle for international law or to find that it has been written into the SPS Agreement. The Appellate Body's awareness of precaution, the dynamics of scientific research and the nature of scientific uncertainty is to be welcomed. This awareness is helpful in dealing with new and emerging issues, such as the question of when a risk assessment relied upon by a WTO member becomes outdated by virtue of subsequent scientific developments. If maintained, an overly rigid approach to risk assessment, with a tight temporal focus, will inadequately acknowledge the natural processes of flux in the development of scientific knowledge.