The Treasury

Global Navigation

Personal tools


Environmental Risk Management in New Zealand - Is There Scope to Apply a More Generic Framework? - PP 06/06

Precautionary principle: origin, definitions and interpretation

The following section outlines the origin and various definitions and interpretations of the precautionary principle.

Widespread application of the precautionary principle

Although the precautionary principle originated in Europe in the early 1970s, it was not until the 1992 United Nations Conference on Environment and Development that the principle received broad international recognition. It was positioned as an underlying element of the broader framework of sustainable development. Since then, it has spread rapidly in multilateral agreements, international laws and domestic laws and policies dealing with: climate change, biodiversity, endangered species, fisheries management, wildlife, trade, food safety, pollution controls, chemicals regulation, exposure to toxins, and other environmental and public health issues (Peterson, 2006). It is being applied in the context of a broader risk management framework in the United States, European Union, United Kingdom and Canada, although there is some variation in how it is being interpreted and applied.

Definition of  the precautionary principle

While there are numerous definitions, the most widely quoted is the one in the Rio Declaration (Principle 15) as previously outlined. Under this definition, the triggering factor is the “threat” of serious or irreversible damage. Once the approach has been triggered, the wording “allows” but “does not require” action to be taken and leaves this open for governments to decide on a case-by-case basis. There are similar definitions in various international treaties including: the 1992 Convention on Climate Change, the 1992 Convention on Biological Diversity and the 2000 Protocol on Biosafety.

The principle's general formulation is both a strength and a weakness.

There is much criticism of the precautionary principle due to its lack of clarity (eg, Majone, 2002; Treich, 2001). However, the general formulation is both the strength and weakness of the precautionary principle. It is a strength because it has a high degree of generality and may be applied to all environmental protection and health safety issues, whereas excessive prescription could remove the flexibility needed to take into account the circumstances of each case (eg, Cooney, 2005; Peterson, 2006). It is also a weakness because it offers little guidance for regulatory policies (Treich, 2001).

While most definitions of the precautionary principle share common features, there are some key areas of difference (Peterson, 2006):

  • What level of threat or harm is sufficient to trigger application of the principle (the threshold of harm)?
  • Are the potential threats balanced against other considerations, such as costs or non-economic factors, in deciding what precautionary measures to implement?
  • Does the principle impose a positive obligation to act or simply permit action?
  • Where does the burden of proof rest to show the existence or absence of harm?
  • Is liability for environmental harm assigned and, if so, who bears the liability?

Forms of the precautionary principle

Based on these differences, different versions of the principle can be categorised as weak, moderate or strong (Cooney, 2005; Peterson, 2006; Wiener, 2002). The particular formulation of the principle is a key factor determining the economic consequences of precautionary measures.

Weak version

The least restrictive allows, but does not require, preventive measures.

The weak version is the least restrictive and allows preventive measures to be taken in the face of uncertainty, but does not require them (eg, Rio Declaration 1992; United Nations Framework Convention of Climate Change 1992). To satisfy the threshold of harm, there must be some evidence relating to both the likelihood of occurrence and the severity of consequences.

Some, but not all, require consideration of the costs of precautionary measures. Weak formulations do not preclude weighing benefits against the costs. Factors other than scientific uncertainty, including economic considerations, may provide legitimate grounds for postponing action.

Under weak formulations, the requirement to justify the need for action (the burden of proof) generally falls on those advocating precautionary action. No mention is made of assignment of liability for environmental harm.

Moderate version

The presence of an uncertain threat is a positive basis for action.

In moderate versions of the principle, the presence of an uncertain threat is a positive basis for action, once it has been established that a sufficiently serious threat exists. For example, the United Kingdom Biodiversity Action Plan states:

“In line with the precautionary principle, where interactions are complex and where the available evidence suggests that there is a significant chance of damage to our biodiversity heritage occurring, conservation measures are appropriate, even in the absence of conclusive scientific evidence that damage will occur." (Department of the Environment (UK), 1994)

Usually, there is no requirement for proposed precautionary measures to be assessed against other factors such as economic or social costs. The trigger for action may be less rigorously defined, for example, as “potential damage”, rather than as “serious or irreversible” damage as in the weak version. Liability is not mentioned and the burden of proof generally remains with those advocating precautionary action.

Strong version

The strong version differs from other versions in requiring action and reversing the burden of proof.

Strong versions of the principle differ from the weak and moderate versions in reversing the burden of proof. Strong versions justify or require precautionary measures and some also establish liability for environmental harm, which is effectively a strong form of “polluter pays”. For example, the Earth Charter (2000) states:

“When knowledge is limited apply a precautionary approach …. Place the burden of proof on those who argue that a proposed activity will not cause significant harm, and make the responsible parties liable for environmental harm.”

Reversal of proof requires those proposing an activity to prove that the product, process or technology is sufficiently “safe” before approval is granted. Requiring proof of “no environmental harm” before any action proceeds implies the public is not prepared to accept any environmental risk, no matter what economic or social benefits may arise (Peterson, 2006). At the extreme, such a requirement could involve bans and prohibitions on entire classes of potentially threatening activities or substances (Cooney, 2005).

There has been a gradual transformation to a stronger form.

Over time, there has been a gradual transformation of the precautionary principle from what appears in the Rio Declaration to a stronger form that arguably acts as restraint on development in the absence of firm evidence that it will do no harm.

There are substantial issues around how the burden of proof is applied.

There are substantial issues around how the burden of proof is applied. Through increasing costs, this can delay innovation and affect the viability of innovative industries and those that depend on their products. This may encourage them to change their activities or relocate to other jurisdictions with less stringent standards of proof, resulting in a loss in capability in the home country.

Critique of the precautionary principle

The likelihood of problems arising depends on the way the precautionary principle is formulated and implemented.

There are a number of problems associated with applying the precautionary principle. The likelihood of these problems arising depends on the way the principle is formulated and implemented. Application of the principle within an integrated risk management framework, with well designed guidelines that allow for a range of options and the costs, benefits and risks to be considered, may help avoid these problems.

Peterson (2006) summarises the most frequent criticisms of the principle:

  • Excessive discretion - where decision-makers have a high level of discretion as to when and how to apply the precautionary principle and the regulatory framework is not applied consistently, this may lead to unpredictable and inconsistent environmental management decisions, which create high costs for businesses and inhibit corporate planning (Harding and Fisher, 1999). Lack of clarity can provide opportunity for legal challenge through the courts, where the principle may be interpreted differently from what was intended by the policy maker. This does not provide industry with sufficient guidance or certainty.
  • Reversal of the burden of proof – this could impose excessive costs on developers and producers, although it does not necessarily dictate who will pay the costs. According to Peterson (2006), a more important factor influencing the costs could be the “standard” of proof required to satisfy authorities.
  • Distortion of regulatory priorities – this may occur through application of the precautionary principle (Majone, 2002) by redirecting regulatory attention from known or plausible hazards to speculative or ill-founded ones (Graham, 2004). This could increase environmental damage. It highlights the need to prioritise risks within a broader risk management framework and to assess the costs and benefits.
  • Stifling of technological innovation and paralysis of development – this is claimed by Graham (2004) and Hahn and Sunstein (2005) and could occur under stronger versions of the principle, depending on how they are applied and the standard of proof of safety required. The counter-argument is that application of the precautionary principle may lead to some innovation in alternatives if firms know that certain avenues have been closed off. However, this is likely to be at the margin compared with the wider stifling effect that strong forms of the principle can have.
  • Costs of precautionary measures - some highlight the costs of measures taken to avoid potential harm, but frequently overlook or discount the potential benefits, which could be substantial (eg, the experience with asbestos). If the hazard does not eventuate, expenditure on avoidance measures may be seen as wasted. However, in a cost-benefit context, this may not be the case if the expected benefits outweighed the costs, the most cost-effective and efficient alternative was chosen and the best available information was taken into account at the time.
  • Perverse consequences from precautionary measures - may result from a failure to recognise that regulatory measures have costs, as well as benefits, and may themselves give rise to risks (Hahn and Sunstein, 2005).
  • Misuse as a protectionist barrier - the precautionary principle is open to misuse and opportunistic manipulation by rent-seeking and commercial interests (Gollier and Treich, 2003; Graham, 2004; Majone, 2002; Treich, 2001). For example, commercial interests may oppose a competing product on the grounds that it could have unproven harmful impacts. The precautionary principle may also be used as a disguised form of protectionism and has been implicated in a number of trade disputes. An example is the European Union imposing import barriers on hormone treated beef and genetically modified food products.
Page top