The Precautionary Principle

Report of UNESCO's expert group on the Precautionary Principle, adopted by the World Commission on the Ethics of Scientific Knowledge and Technology (COMEST) at its fourth session (March 2005). Available in English and French.

Below I quote Annex 1. of the report in its entirety.

Practical guidance: frequent questions about the precautionary principle

What is the goal of the PP?

The goal of the PP is to protect humans and the environment against uncertain risks of human action by means of pre-damage control (anticipatory measures). The PP provides a rational approach to the satisfactory and ethically justified management of uncertain risks to public health, society or environment. It aims to use the best of the ‘systems sciences’ of complex processes to make wiser decisions. The PP is to supplement, but not necessarily replace, other management strategies that fall short of being able to handle large-scale scientific uncertainty and ignorance: ‘When human activities may lead to morally unacceptable harm that is scientifically plausible but uncertain, actions shall be taken to avoid or diminish that harm’.

What conditions trigger the consideration of the PP?

Generally speaking, the PP applies when there is plausible evidence of possible harm but scientific uncertainty and ignorance makes it impossible to reliably quantify and characterize the risks. More specifically, one needs to check whether:
* there exist considerable scientific uncertainties or even ignorance about the anticipated harm;
* there exist scenarios (or models) of possible harm that are scientifically reasonable (that is, based on some scientifi cally plausible reasoning);
* it is currently impossible to reduce the uncertainties without at the same time increasing ignorance of other relevant factors by higher levels of abstraction and idealization;
* the potential harm is indeed sufficiently serious or even irreversible for present or future generations or otherwise morally unacceptable;
* there is a need to act now, since effective counter-action later will be made significantly more difficult or costly at any later time.

What actions are consistent with the PP?

The PP calls for measures that either are likely to prevent the possible harm from occurring or are likely to contain or reduce the possible harm should it occur. In principle, there will always be a range of possible strategies that would satisfy this requirement. One may impose certain constraints on the range of such measures. One may, for example, require that the actions be:
(a) non-discriminatory in their application, i.e. similar situations are treated similarly,
(b) consistent in scope and nature with comparable measures from equivalent areas,
(c) proportional to the chosen level of protection and the scope of the harm,
(d) chosen with due consideration of positive and negative consequences (including non-monetary costs and benefits) and with an assessment of the moral implications of both action and inaction,
(e) subject to continuous review and monitoring, and that the main burden of providing evidence for safety rests on the proposers of a new technology or activity.
Even under these conditions a variety of possible precautionary actions may remain, ranging from simple restrictions upon a practice, strengthening the resilience of the system, the development of effective controlling (remediating) technologies, to a total ban of the activity. The final choice will always be value-based.

Who decides on the PP?
What is an appropriate decision procedure?

Since the application of the PP involves the explicit consideration of values that are affected by it, since values differ in society, the processes leading up to a final choice of action should be largely participatory and inclusive. The cultural plurality in risk attitudes varying from risk-aversion to willingness to take risks implies that the question of how society ought to deal with risks can only be answered in public debate – a debate in which people will necessarily discuss their perception of risks and risk management from different points of view and different conceptual and ethical frameworks. Only if decisions can acquire some robustness in terms of social and political acceptability do they stand a chance of being effective over time.

What makes a reasonable ground for concern?

A mere fantasy or crude speculation that an activity or new technology causes harm is not enough to trigger the PP. Grounds for concern that can trigger the PP are limited to those concerns that are plausible or scientifi cally tenable (that is, not easily refuted). Some form of scientific analysis is mandatory. The hypothesis that an activity can cause harm should be consistent with background knowledge and theories. If a hypothesis requires one to reject widely accepted scientifi c theories and facts, then it is not plausible. The hypothesis should posit causal mechanisms or processes, or if no causal mechanism is known, there should be some evidence of a possible statistical correlation. However, if a hypothesis posits radically new and unfamiliar mechanisms and processes, it is not plausible. Further, obscure and complex hypotheses are not as plausible as simple and straightforward ones.

Under what conditions is the PP not the best way to go?

Generally speaking, there are three classes of cases where the PP should not be used. The first class is when the scientific uncertainties can be overcome in the short term through more research, or when the uncertainties are simply understood as low probability of harm (in that case it is only a question of the chosen level of protection). However, in some cases the potential consequences can be of a nature and magnitude that makes them morally unacceptable even if the probability is very low, for instance, extinction of mankind. The second class is when the potential harm is not morally unacceptable, e.g. when the harm is restricted to individuals who voluntarily engage in the activity and are informed about the possible consequences. The third class of cases is when the harm is reversible and it is likely that effective counter-action is not becoming more diffi cult or costly, even when one waits until the fi rst manifestations of the harm eventually occur. In this case a ‘wait and see’ strategy might be used.

Some say that the PP does not provide clear guidance/is not a good administrative principle. Is that a problem?

The PP provides a rational framework for managing uncertain risks. However, the PP
in itself is not a decision algorithm and thus cannot guarantee consistency between cases. Just as in legal court cases, each case will be somewhat different, having its own facts, uncertainties, circumstances, and decision-makers, and the element of judgement cannot be eliminated. In this respect it resembles other ethical and legal principles. Principles of law constitute important tools for crystallization of new concepts and values. A strength of the PP being a principle is its open-endedness and fl exibility, which creates a possibility and an incentive for social learning. Different areas of application and different legal frameworks may lead to more specific guidance and regulations. The repeated use of State practice and consistent opinio juris are likely to transform the PP into a customary norm. Among the principles emanating from international declarations, the PP is legally relevant and cannot be disregarded by the countries in the international order, nor by legislators, policy makers and courts in the internal sphere. Precautionary measures should in any case be judged transparently on a case-by-case basis, and be subjected to scrutiny from many parties.