The precaution principle in international agreements

The precaution principle is not yet formally enshrined in international environmental law. But it has begun to appear in a number of national and international agreements and looks for further extension in formal law. For example, the US Federal Water Pollution Control Act of 1972 contains a provision for zero discharges of pollutants, based on the best available technology. The Federal Insecticide Fungicide and Rodenticide Act of 1976 places the burden of proof on the manufacturer to show that a proposed formulation is safe. Other national legislation relating to toxic or potentially big-accumulative substances adopts similar positions (see Cameron and Abouchar, 1991, for a review).

In practice, the precautionary principle is being applied in various stages:

Stage 1: A ban on substances that are known or presumed to be toxic, or persistent, or big-accumulative in commons arenas (e.g. seas, space, atmosphere).

Stage 2: A strict control, using burden of proof on promoter and application of best available technology, on activities or substances where a causal link to possibly severe environmental damage is deemed likely.

Stage 3: The control of hazardous wastes, via the application of scientific and economic balancing, notably BATNEEC (see below), clean technology, company audits, and regulatory audits where the balance of probabilities favours action sooner rather than later.

Stage 4: The reduction in nutritive elements in common areas where accumulation could prove costly, and where staged action is consistent with a "least regrets" policy.

Stage 5: The coupling of more research and programmed preventative investments in global change issues, notably global warming, sealevel rise, and loss of biodiversity.

The prior statement of the precautionary principle came in the London Declaration of the Second North Sea Conference, 1990: "In order to protect the North Sea from possibly damaging effects of the most dangerous substances, a precautionary approach is necessary which may require action to control inputs of such substances even before a causal link has been established by absolutely clear scientific evidence."

This has been converted into programmes of action by the Oslo and Paris Commissions for controlling the deposition of toxic wastes to air and land respectively. Subsequently the Bergen Ministerial Declaration on Sustainable Development in the ECE region (May 1990) stated: "Where there are threats of serious or irreversible damage, lack of full scientific certainty should not be used as a reason for postponing measures to prevent environmental degradation." Article 130R of the Single European Act of 1985 also refers to the principle of preventative action.

All these positions are not absolute. Coupled to them is a call for more research, so as to be sure that risky strategies of precaution are always advanced with the support of carefully judged scientific and economic appraisal. This is not a cop-out. It is a recognition that, under conditions of uncertainty, there could be serious inefficiencies of resource allocation in acting too expensively, too precipitously. Precaution thus is not an unfettered principle.