The precautionary principle is a doctrine that states that if an action carries an inherent risk of harm to the public, but there is no scientific consensus that such harm will result, the onus of showing that the action will not cause such harm is on the person advocating for the action. In other words, the precautionary principle advocates for policy makers to err on the side of caution where there is a potential for public harm. Most often, this principle is expressed in the context of environmental regulations, namely global warming. While the precautionary principle is often part of the natural decision-making of governments on a day-to-day basis, it is not usually statutorily required. However, some governing bodies, such as the European Union (EU), have embodied the doctrine in many of their laws.
There are two basic underlying tenets of the precautionary principle. First, policy makers must understand the risks of harm that stems from a particular action prior to its occurrence. Second is the existence of an obligation to take reasonable measures to avoid such harm even if there is no scientific proof that the harm will result. While these two tenets are fairly general and could be applied to any policy decision, the precautionary principle is typically only applied when there is an adequate reason to believe that a significant risk of harm exists. Additionally, the second tenet’s statement about “reasonable measures” implies that the cost of taking — or not taking — such measures should be balanced against the risk and magnitude of the potential harm.
The precautionary principle is most commonly illustrated in terms of environmental effects of policy. For example, governments may create regulations that restrict the carbon emissions of certain industries based on the potential effects of a high level of emissions on global warming, even if there is no scientific proof that those emissions actually contribute to the problem. The mere likelihood that some harm will result is enough under the precautionary principle to justify such regulation. It does not, however, flow from the principle that governments should completely shut down the industry considering that only “reasonable measures” should be taken.
Generally speaking, the precautionary principle is just one of many approaches a government’s policy makers may employ when deciding how to handle an issue. However, some governmental bodies have codified the principle within their statutes. For instance, the European Commission has placed different articulations within EU laws. Not only is it explicitly stated within some of the EU’s environmental statutes, but it has expanded into other areas such regulation of the safety of food and other forms of consumer protection.