A more substantive precautionary principle of international law is evolving as new treaties articulate new measures of precaution in different contexts. Although there is considerable controversy over how to articulate or define a precautionary "principle" of law, the goal is to ensure that the mere lack of scientific knowledge about risks cannot justify a failure to take appropriate precautions. Where we have sufficient evidence of risk, we often take precautions, despite a lack of certainty about those risks. The question arises, however, what the difference is between adopting a precautionary principle and merely taking precautions. Put another way, what is to be gained by adopting a precautionary principle at all, as compared to merely taking precautions? This Article explores that question by using the example of food safety regulation in the United States. My principal conclusion is that although precautionary measures for achieving food safety in the United States are some of the oldest and most successful in the world, even such measures fall short when they are evaluated from the unifying perspective of the precautionary principle.

Any articulation of the precautionary principle would apply at two distinct levels of decisionmaking: (1) decisions about the factual situations that trigger justifiable recourse to precautionary measures; and (2) the management decisions to select the desired level of protection and to establish measures to achieve that level of protection. The first aspect involves primarily risk assessment, while the second is part of risk management. This Article examines these levels of decisionmaking in the regulation of food safety in the United States. My objective is not, of course, to provide a comprehensive survey of that regulatory structure. Rather, the goal is to use food safety regulation to find concrete examples of the difference between merely taking precautions and adopting the precautionary principle. A byproduct of this examination is a more detailed account of what it means to adopt the precautionary principle.