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The precautionary principle



Communication (COM(2000) 1final) on the precautionary principle


  • It explains the precautionary principle which enables a rapid response to be given in the face of a possible danger to human, animal or plant health, or to protect the environment.
  • In particular, where scientific data do not permit a complete evaluation of the risk, recourse to this principle may, for example, be used to stop distribution or order withdrawal from the market of products likely to be hazardous.
  • It establishes common guidelines on the application of the precautionary principle.


The precautionary principle is detailed in Article 191 of the Treaty on the Functioning of the European Union. It aims at ensuring a higher level of environmental protection through preventative decision-taking in the case of risk. However, in practice, the scope of this principle is far wider and also covers consumer policy, European Union (EU) legislation concerning food and human, animal and plant health.

The definition of the principle shall also have a positive impact at international level, so as to ensure an appropriate level of environmental and health protection in international negotiations. It has been recognised by various international agreements, notably in the Sanitary and Phytosanitary Agreement (SPS) concluded in the framework of the World Trade Organisation (WTO).

Recourse to the precautionary principle

According to the European Commission the precautionary principle may be invoked when a phenomenon, product or process may have a dangerous effect, identified by a scientific and objective evaluation, if this evaluation does not allow the risk to be determined with sufficient certainty.

Recourse to the principle belongs in the general framework of risk analysis (which, besides risk evaluation, includes risk management and risk communication), and more particularly in the context of risk management which corresponds to the decision-making phase.

The Commission stresses that the precautionary principle may only be invoked in the event of a potential risk and that it can never justify arbitrary decisions.

The precautionary principle may only be invoked when the three preliminary conditions are met:

  • identification of potentially adverse effects;
  • evaluation of the scientific data available;
  • the extent of scientific uncertainty.

Precautionary measures

The authorities responsible for risk management may decide to act or not to act, depending on the level of risk. If the risk is high, several categories of measures can be adopted. This may involve proportionate legal acts, financing of research programmes, public information measures, etc.

Common guidelines

The precautionary principle shall be informed by three specific principles:

  • the fullest possible scientific evaluation, the determination, as far as possible, of the degree of scientific uncertainty;
  • a risk evaluation and an evaluation of the potential consequences of inaction;
  • the participation of all interested parties in the study of precautionary measures, once the results of the scientific evaluation and/or the risk evaluation are available.

In addition, the general principles of risk management remain applicable when the precautionary principle is invoked. These are the following five principles:

  • proportionality between the measures taken and the chosen level of protection;
  • non-discrimination in application of the measures;
  • consistency of the measures with similar measures already taken in similar situations or using similar approaches;
  • examination of the benefits and costs of action or lack of action;
  • review of the measures in the light of scientific developments.

The burden of proof

In most cases, European consumers and the associations which represent them must demonstrate the danger associated with a procedure or a product placed on the market, except for medicines, pesticides and food additives.

However, in the case of an action being taken under the precautionary principle, the producer, manufacturer or importer may be required to prove the absence of danger. This possibility must be examined on a case-by-case basis. It cannot be extended generally to all products and processes placed on the market.


For more information, see:


Communication from the Commission on the precautionary principle (COM(2000) 1 final of 2 February 2000)

last update 30.11.2016