Perils of the Precautionary Principle:
Lessons from the American and European Experience
D. Graham, Ph.D.
Office of Information and Regulatory Affairs
Office of Management and Budget
The Heritage Foundation
October 20, 2003
concept of a universal precautionary principle apparently has its origins
in early German and Swedish thinking about environmental policy, particularly
the need for policymakers to practice foresight in order to prevent long
range environmental problems. The concept was included in the Amsterdam
Treaty an important step toward establishment of the European
Union but the concept was left undefined and was applied only
to environmental policy. In the last 20 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.
In recent years there has been growing international interest in the subject
of precaution. Reacting to criticism that the principle was too ambiguous,
the European Commission in 2000 issued a formal "Communication"
about the precautionary principle. This Communication extended the applicability
of the principle to public health and consumer protection as well as environmental
policy. For several years, 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 USA. 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
Sandin has 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.
Given the ambiguity about the precautionary principle, it may be useful
to start with a dictionary definition. 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 OMB, I served for 17 years on the faculty of the Harvard
School of Public Health. In that capacity I learned that public health
historians have documented the preventable pain and suffering that can
occur from insufficient consideration of the need for precaution. In the
United States we felt that pain as a result of how we handled emerging
science about tobacco, lead and asbestos. Historians teach us that 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.
Take the link between smoking and lung cancer. Although this link now
seems obvious, in the middle of the previous century the link was not
obvious to many competent and thoughtful physicians. They knew that many
lifetime smokers never developed lung cancer; they also knew 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. In the final analysis, it took large-scale
statistical studies of smokers to resolve the issue. In fact, there was
a large scale study of the health of British physicians that played an
important role in building the medical consensus against smoking.
In each of these examples (tobacco, lead and asbestos), it was epidemiology
rather than the experimental sciences that played the most pivotal role
in identifying health risks. Ironically, it is epidemiology that 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 previously
argued that this is the norm in regulatory science, while 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 in fact there are cases of predictions of doom that have simply not
Consider the "dismal theorem" of the Reverend Thomas Malthus
(1798). He hypothesized that population would grow exponentially while
sources of sustenance would only grow arithmetically. The result, he predicted,
would be that living standards would fail to rise beyond subsistence levels.
However, history has shown this theorem to be incorrect. Malthus did not
foresee the technological advances that have allowed both population and
standard of living to risk steadily and substantially.
A more recent example in the USA concerns the popular artificial sweetener
saccharine. FDA declared the regulatory equivalent of war against this
product on the basis of experimental laboratory test results. The finding
was that huge doses of saccharine cause bladder cancer in rodents. While
FDA attempted to ban saccharine based on this evidence, the US Congress
overturned FDA's action. With the benefit of hindsight, it now appears
that FDA's attempted ban may have been poorly grounded in science. Just
recently, the federal government in the USA removed saccharine from the
official list of "carcinogens" for two reasons: experimental
biologists have found that saccharin causes bladder tumors in rodents
through a mechanism (cell proliferation) that is unlikely to be relevant
to low-dose human exposures; and large-scale epidemiological studies of
saccharine users have found no evidence that the product is linked to
excess rates of bladder cancer in people.
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 auto-immune disorders, cell phones and brain cancer,
and disruption of the endocrine system of the body from multiple, low-dose
exposures to industrial chemicals. In each of these cases, early studies
that suggested danger were not replicated in subsequent studies performed
by qualified scientists. Efforts at replication or verification were simply
not successful. At the same time, when early studies are replicated by
independent work, such as occurred with the acute mortality events following
exposure to fine particles in the air, it is important for public health
regulators to take this information seriously in their regulatory deliberations.
Given that the dynamics of science are not predictable, it is important
to consider the dangers of excessive precaution. One of those is the threat
to technological innovation. Imagine 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,
the cell phone and so forth? By its very nature, 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 USA regret some of the prior policy steps
we have taken on the basis of precaution. In US energy policy, for example,
the Three Mile Island incident had a large policy impact, though even
today there is no evidence of significant public health harm caused by
the accident at Three Mile Island. In fact, there has been a de facto
moratorium on the construction of new nuclear power plants in the USA.
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
In comparing the actions of different countries and regions, it is important
to avoid the fallacy that Europe is precautionary while the USA is not.
The late Aaron Wildavsky, in his studies of risk regulation, observed
that cultures engage in risk selection. Some have argued that the USA
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 USA on diesel engine exhaust, environmental tobacco smoke, and lead
in gasoline. In fact, the recent comparative research by Professor Jonathan
Wiener of Duke University has found no evidence to support the popular
myth that Europe is generally more precautionary than the USA.
A subjective concept such as "the precautionary principle" is
itself dangerous because it permits what conservative scholars have called
"precaution without principle". In particular, the principle
may be easily manipulated by commercial interests for rent-seeking purposes.
According to Conko and Miller, students of biotech policy, the EU policy
on genetically modified organisms "creates a bizarre bureaucratic
distinction that favors certain classes of products widely made in Europe."
This practice is hardly new. That is precisely what the World Trade Organization
found in its earlier decision against the EU ban on hormone-treated beef,
a ban that had no grounding in public health science.
Although there are many reasons to be skeptical about Europe's stance
on precaution, there are recent signs of progress from Europe. Take the
response of Brussels to "mad cow's disease". Once the British
government and industry had taken all reasonable steps to address this
problem, Brussels instructed Member States of the EU to lift their bans
on beef imports from the UK. All member states complied except France,
who argued that French beef might still be safer than British beef and
that France has the right to invoke the precautionary principle. Brussels
took France to the European Court of Justice, where the Court ruled against
France, indicating that speculative appeals to the precautionary principle
must have some grounding in science.
Much more recently, the EC has rejected an unauthorized use of the precautionary
principle by the provincial government of Upper Austria. In March of this
year Austria notified Brussels of its proposed ban of genetically modified
seeds that the EC had approved for cultivation under the EC Directive
90/220. Upper Austria appealed to the precautionary principle but Brussels
overruled them: "Recourse to the precautionary principle presupposes
that potentially dangerous effects . . . have been identified, and that
scientific evaluation does not allow the risk to be determined with sufficient
certainty." The EC noted that Upper Austria had not made this case
and there was certainly nothing unique about the safety of GM seeds in
While it is fashionable to criticize Europe on the subject of precaution,
and much of that criticism is deserved, it should also be noted that the
EC'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 US government:
Precaution is a necessary and useful concept but it is subjective and
susceptible to abuse by policy makers for trade purposes.
Scientific and procedural safeguards need to be applied to risk management
decisions based on precaution.
Adoption of precautionary measures should be preceded by objective scientific
evaluations, including risk assessment and benefit-cost analysis of alternative
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
Opportunities for public participation to discuss efficiency,
fairness and other public values are critical to sound risk management.
In OMB's 2003 Report to Congress on the Costs and Benefits of Regulation,
we also emphasize the important role that analytic tools have in informing
regulatory judgments about precaution. There are offshoots of cost-benefit
analysis called value-of-information analysis and decision analysis that
were designed precisely for the purpose of analyzing problems with large
degrees of scientific uncertainty. These tools are already widely used
in engineering and business and are increasingly applied to environmental
issues. We urge readers to consult OMB's report for references to this
growing analytic literature on precautionary regulation.
In summary, there are two major perils associated with an extreme approach
to precaution. One is that technological innovation will be stifled, and
we all recognize that innovation has played a major role in economic progress
throughout the world. A second peril, more subtle, is that public health
and the environment would be harmed as the energies of regulators and
the regulated community would be diverted from known or plausible hazards
to speculative and ill-founded ones. For these reasons, please do not
be surprised if the US government continues to take a precautionary approach
to calls for adoption of a universal precautionary principle in regulatory