Since the beginning of serious environmental regulation in the 1970s, the United States (and later Europe) has increasingly, and seemingly inexorably, adopted a risk-based approach to the regulation of environmental threats and, in particular, of toxic chemicals and pesticides. In these regulatory systems-the Toxic Substances Control Act' (TSCA); the Federal Insecticide, Fungicide, and Rodenticide Act2 (FIFRA); and the toxics provisions of general pollution statutes3-the extent of regulation is primarily determined by a highly quantitative evaluation of the toxic potency of a chemical and the degree of human exposure, resulting in quantitative assessment of the likelihood of harm to human health. An aggressive and comprehensive program of chemical regulation is severely restricted by the information demands of this approach, however, because a wide "data gap" exists between the information required to justify regulation and the information that is actually available.
This Article has three objectives and three central Parts. First, it traces the rise of risk as the basis for chemical regulation, distinguishing between two different meanings and functions of risk in chemical regulation. second, it demonstrates how the adoption of particular risk-based strategies can result in a severe imbalance between the demand for and the supply of chemical information.4 Third, building on the different functions and meanings of risk, it offers a fundamentally different approach to chemical regulation, which reduces the demand for chemical information (bridging the data gap, so to speak) rather than attempting the ultimately unattainable goal of completely supplying it (filling the gap). This Article is thus a variation on the Symposium theme of "harnessing the power of information": It advocates harnessing the demand for information as the most promising way to make the existing and foreseeable supply of chemical information more effective in supporting a robust program of protective regulation.
II. The Rise of Risk
Risk has a lengthy history in the legal response to damage to persons and property, and over time different legal frameworks have emphasized different functions and meanings of risk.5 Before tracing the conceptual development of risk, therefore, it will help to distinguish the functions and meanings. In order to be effective, or even coherent, a regulatory system must describe both the preexisting conditions that call for regulatory attention and the future conditions that regulatory action is supposed to achieve. The "before" and "after" states of the world can be called the trigger and standard, respectively.6 The trigger defines the problem, and the standard describes the appropriate regulatory response. Thus, under the Clean Air Act,7 if the Environmental Protection Agency (EPA) finds that a facility is emitting a hazardous air pollutant (the trigger), then it must apply restrictions equivalent to the maximum achievable control technology (the standard).8 Under the Delaney Clause,9 if the Food and Drug Administration (FDA) finds that a nonpesticide chemical causes cancer in man or animal (trigger), then it must prohibit the use of the chemical as a food additive (standard).10
As we will see, risk has been used for both of these functions in chemical regulation, that is, as the definition of the problem to be solved and as the means of disciplining or constraining the response to the identified risk. Risk is able to perform these dual functions because it has two distinct lexical meanings. According to Merriam-Webster's, risk means both "possibility of loss or injury" and "the chance of loss or the perils to the subject matter of an insurance contract; also: the degree of probability of such loss."" The first has an open-ended meaning roughly equivalent to "danger" or "threat." The second meaning is probabilistic and implies greater precision. It suggests a quantitative approach to describing the extent of the likelihood of a harm occurring. …