Skip to content

About PERC

All Areas of Focus

All Research

Facing The Unknown

  • John Graham

    The concept of a universal precautionary principle apparently has its origins in early German and Swedish thinking about environmental policy. The idea was to encourage policymakers to practice foresight in order to prevent long-range environmental problems. The concept was included in the Amsterdam Treaty of 1997, a step toward establishment of the European Union, but the concept was left undefined and was applied only to environmental policy. In the past twenty years, there have been numerous references to precaution in various international treaties, statements of advocacy groups, and academic writings, but the significance of the principle in international law remains uncertain.

    There has been growing international interest in precaution. Reacting to criticism that the principle was too ambiguous, the European Commission in 2000 issued a formal “Communication” that extended the applicability of the precautionary principle to public health and consumer protection as well as environmental policy. The German Marshall Fund has been working with Duke University to sponsor several informal dialogue sessions involving governmental officials and academics from Europe and the United States. Several months ago, the Canadian government released a “framework” document for the application of precaution in science-based decisions about risk.

    The United States government believes it is important to understand that, notwithstanding the rhetoric of our European colleagues, there is no such thing as the precautionary principle. Indeed, the Swedish philosopher Per Sandin recently documented 19 versions of the precautionary principle in various treaties, laws, and academic writings. Although these versions are similar in some respects, they have major differences in terms of how uncertain science is evaluated, how the severity of consequences is considered, and how the costs and risks of precautionary measures are considered. The United States government believes that precaution is a sensible idea, but there are multiple approaches to implementing precaution in risk management. A single “precautionary principle” is not one of them.


    Webster’s 2nd edition of the New World Dictionary defines precaution as “care taken beforehand” or “a measure taken beforehand against possible danger.” Understood in this way, precaution is a well-respected notion that is practiced daily in the stock market, in medicine, on the highway, and in the workplace. In both business and politics, decision makers seek the right balance between taking risks and behaving in a precautionary manner.

    Before joining the Office of Management and Budget, I served for 17 years on the faculty of the Harvard School of Public Health. I learned that public health historians have documented the preventable pain and suffering that can occur from insufficient consideration of the need for precaution. We in the United States felt that pain as a result of how we handled emerging science about tobacco, lead, and asbestos. The major health problems from these substances could have been reduced or prevented altogether if decision makers had reacted to early scientific indications of harm in a precautionary manner.

    We should not belittle the scientific complexities in each of these examples, however. Take the link between smoking and lung cancer. Although this link now seems obvious, in the middle of the previous century it was not obvious to many competent and thoughtful physicians. They knew that many lifetime smokers never developed lung cancer and that some lung cancer patients had never been smokers. Compounding the problem was the inability of laboratory scientists to produce lung tumors in laboratory animals exposed by inhalation. It took large-scale statistical studies of smokers to resolve the issue, including a large-scale study of the health of British physicians.

    In each of these examples (tobacco, lead, and asbestos), epidemiology, not the experimental sciences, played the pivotal role in identifying health risks. Ironically, epidemiology is now one of the more controversial contributors to public health science.


    There is no question that postulated hazards sometimes prove more serious and/or widespread than originally anticipated. Ralph Nader has argued that this is the norm in regulatory science, and the European Commission recently issued a report of case studies where hazards appear to have been underestimated. However, the dynamics of science are not so easily predicted. Sometimes claims of hazard prove to be exaggerated, and some predictions of doom have simply not materialized.


    One is the “dismal theorem” of the Reverend Thomas Malthus, who hypothesized in 1798 that population would grow exponentially while sources of sustenance would only grow arithmetically. Thus, living standards would fail to rise beyond subsistence levels. Malthus did not foresee the technological advances that have allowed both population and standard of living to rise steadily and substantially.

    A more recent example concerns the artificial sweetener saccharine. The Food and Drug Administration attempted to ban saccharine based on experimental laboratory test results showing that huge doses of saccharine cause bladder cancer in rodents. (Congress overturned the FDA’s action.) With the benefit of hindsight, it now appears that the FDA’s attempted ban may have been poorly grounded in science. The federal government recently removed saccharine from the official list of carcinogens.

    Students of risk science are aware that the number of alleged hazards far exceeds the number that are ever proven based on sound science. Consider the following scares: electric power lines and childhood leukemia, silicone breast implants and autoimmune disorders, cell phones and brain cancer, and disruption of the body’s endocrine system from multiple, low-dose exposures to industrial chemicals. In each of these cases, early studies that suggested danger were not replicated in subsequent studies by qualified scientists. On the other hand, when early studies are replicated by independent work, as occurred with the acute mortality events following exposure to fine particles in the air, public health regulators should take this information seriously in their deliberations.

    Given that the dynamics of science are not predictable, it is important to consider the dangers of excessive precaution. One is the threat to technological innovation. Imagine that it is 1850 and the following version of the precautionary principle is adopted: No innovation shall be approved for use until it is proven safe, with the burden of proving safety placed on the technologist. Under this system, what would have happened to electricity, the internal combustion engine, plastics, pharmaceuticals, the Internet, and the cell phone? Technological innovation occurs through a process of trial-and-error and refinement, and this process could be disrupted by an inflexible version of the precautionary principle.

    Many risk specialists in the United States regret some policy steps we have taken on the basis of precaution. The Three Mile Island incident, for example, had a large policy impact-a de facto moratorium on the construction of new nuclear power plants in the United States-although even today there is no evidence that the accident caused significant public health harm. We have become more deeply dependent on fossil fuels for energy, and now precaution is being invoked as a reason to enact stricter rules on use of fossil fuels. Part of the answer may rest with clean coal technologies and renewable energy, but we should not foreclose the advanced nuclear option.

    Some argue that the United States is more tolerant than Europe of the possible risks of bioengineered foods, global climate change, and industrial chemical exposures. However, a fair analysis would also show that Europe has been less precautionary than the United States on diesel engine exhaust, environmental tobacco smoke, and lead in gasoline.

    A subjective concept such as “the precautionary principle” is dangerous because it permits what conservative scholars have called “precaution without principle.” In particular, the principle may be easily manipulated by commercial interests for rentseeking purposes. According to Henry I. Miller and Gregory Conko (Washington Times, Sept. 10, 2003), the European Union policy on genetically modified organisms creates a “bizarre bureaucratic distinction that favors certain classes of products widely made in Europe.” That is precisely what the World Trade Organization found in its earlier decision against the European Union ban on hormone-treated beef, a ban that had no grounding in public health science.


    There are recent signs of progress from Europe. Take the response of Brussels to “mad cow disease.” Once the British government and industry had taken all reasonable steps to address this problem, Brussels instructed member states of the European Union to lift their bans on beef imports from the United Kingdom. All member states complied except France, which invoked the precautionary principle. Brussels took France to the European Court of Justice, which ruled against France, indicating that speculative appeals to the precautionary principle must have some grounding in science.


    While it is fashionable to criticize Europe on the subject of precaution, and much of that criticism is deserved, it should be noted that the European Commission’s official views on precaution are becoming more nuanced. In the February 2000 Communication, for example, we found the following views that are similar to the perspective of the U.S. government:

    1. Precaution is a necessary and useful concept but it is subjective and susceptible to abuse by policymakers for trade purposes.
    2. Scientific and procedural safeguards need to be applied to risk management decisions based on precaution.
    3. Adoption of precautionary measures should be preceded by objective scientific evaluations, including risk assessment and benefit-cost analysis of alternative measures.
    4. There are a broad range of precautionary measures, including bans, product restrictions, education, warning labels, and market-based approaches. Even targeted research programs to better understand a hazard are a precautionary measure.
    5. Opportunities for public participation-to discuss efficiency, fairness, and other public values-are critical to sound risk management.


    In summary, two major perils are associated with an extreme approach to precaution. One is that technological innovation will be stifled. A second peril, more subtle, is that public health and the environment will be harmed as the energies of regulators and the regulated community are diverted from known or plausible hazards to speculative and illfounded ones. For these reasons, please do not be surprised if the U.S. government continues to take a precautionary approach to calls for adoption of a universal precautionary principle in regulatory policy.

    John D. Graham is administrator of the Office of Information and Regulatory Affairs at the Office of Management and Budget. He gave this lecture before the Heritage Foundation on October 20, 2003. It is reprinted with permission.

    Written By
    Related Content