The precautionary principle enables decision-makers to adopt precautionary measures when scientific evidence about an environmental or human health hazard is uncertain and the stakes are high.
It first emerged during the 1970s in German law and has since been endorsed by the international community in a number of environmental treaties and by the EU in the Maastricht Treaty. It has also been recognised in the national legislation of certain Member States.
The precautionary principle divides opinions. Some see it as a pointless and potentially dangerous principle that hinders progress. Others believe that it helps protect human health and the environment from complex hazards.
There is no universally accepted definition of the precautionary principle. Interpretations mainly vary according to the degree of scientific uncertainty that could prompt action by the authorities. The European Commission, UNESCO and the European Environment Agency have each put forward their own definition. Furthermore, the European Court of Justice has contributed to its interpretation and the extension of its scope.
The application of the precautionary principle is also subject to different interpretations. Most experts agree that the precautionary principle does not call for specific measures such as bans or reversing the burden of proof. However, experts and institutions do not agree on the method for determining when to apply precautionary measures (cost-benefit analysis, risk trade-off analysis, cost-effectiveness analysis, pros and cons analysis of action and inaction, etc.). Examples of the application of the precautionary principle include declining bee populations, climate change, fish-stock management, genetically modified organisms or the use of antimicrobials as growth promoters.
The application of the precautionary principle presents many challenges, especially with regard to the treatment of complexity, hazard assessment, research and economic activities. However, it also presents opportunities, mainly regarding the possibility of reducing the overall costs of environmental and health research for society.
The precautionary principle is closely linked to governance. It raises a number of questions regarding risk governance (risk assessment, management and communication). Furthermore, since precautionary measures are usually applied following a political decision based on scientific knowledge, science-policy interfaces are particularly important. Since they are extremely diverse, these interfaces are confronted with several challenges. Finally, there is considerable debate about the link between precaution and innovation. The concept of 'responsible research and innovation', which is enshrined in the Horizon 2020 European research framework programme, seeks to reconcile these two aspects.