3.4 The Precautionary Principle
One of the key principles of environmental law and its application to nanotechnology is thought to be the precautionary principle. There are many references to this principle and its moral and political significances. Originally, it emerged in Germany in the 1970s. One of its well-known formulations is the Principle 15 Rio Declaration from the year 1992, which stated that “[i]n order to protect the environment, the precautionary approach shall be widely applied by States according to their capabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation” [43]. The use of the precautionary principle, however, has been quite limited, mostly on certain types of cost-benefit analyses [44]. There is an application of the precautionary principle in French legislation. The French Barnier law, accepted in 1995 and named for the then – Minister for Agriculture and Fisheries, Michel Barnier, lists certain axiomatic principles for environmental jurisprudence in France. It states inter alia that “[t]he absence of certainties, given the current state of scientific and technological knowledge, must not delay the adoption of effective and proportionate preventive measures aimed at forestalling a risk of grave and irreversible damage to the environment at an economically calculable cost” [8].
Philosophically, this application of the precautionary principle to legislation is weakly grounded, especially in relation to the conceptual footing of the notion of “precaution,” as shown by Jean-Pierre Dupuy and Alexei Grinham, who write:
When the precautionary principle states that the ‘absence of certainties, given the current state of scientific and technical knowledge, must not delay etc.,’ it is clear that it places itself from the outset within the framework of epistemic uncertainty. The assumption is that we know that we are in a situation of uncertainty. It is an axiom of epistemic logic that if I do not know P, then I know that I do not know P. Yet, as soon as we depart from this framework, we must entertain the possibility that we do not know that we do not know something. In cases where uncertainty is such that it entails that uncertainty itself is uncertain, it is impossible to know whether or not the conditions for application of the precautionary principle have been met. If we apply the principle to itself, it will invalidate itself before our eyes [8].
It could be argued that, in specific cases, the precautionary principle has a certain practical value. The principle has been studied by Thomas Faunce and his colleagues, who have explored the principle in an Australian context, evaluating how health hazards of engineered nanoparticles in sunscreens containing titanium dioxide (TiO2) and zinc oxide (ZnO) have been addressed. In 2006, the US Food and Drug Administration (FDA) addressed the risks caused to humans and the environment with regard to different consumer products, such as sunscreens. After this, Faunce and his colleagues in Australia specifically evaluated whether the precautionary principle was utilized by the Australian Therapeutic Goods Administration (TGA) regarding the permission to approve marketing of the sunscreens. The specific problem of the precautionary principle is that it is extremely difficult to assess what level of risk is acceptable. The principle is ambiguous, allowing random application and possibly preventing research and development that might be useful in alleviating the environmental harm it causes. Furthermore, Faunce and his coauthors note that “the precautionary principle, on any rational analysis, does not express some incontrovertible, monolithic regulatory truth, but rather sets framework within which precautionary measures practicably may be taken” [45].
In their conclusion, the authors note that assessing the legal framework with the precautionary principle presents challenges. It is practically impossible to evaluate what measures exist for legislators that could be based on the precautionary principle. In the case of introducing sunscreens with engineered nanoparticles to the consumer market, the alternatives are limited. It would be possible to introduce a total ban on the use of engineered nanoparticles or to introduce a requirement that engineered nanoparticles are considered new ingredients when sunscreens are evaluated. A third option would be to introduce labels that inform consumers to notice that engineered nanoparticles were used to develop the sunscreen. Finally, it would be possible to have a sort of panel or other bureaucratic institution to follow the marketing and sales of sunscreens that contain engineered nanoparticles, such as TiO2 and ZnO. However, none of these options could be considered very meaningful, according to Faunce and his coauthors. Thus, the precautionary principle lacks usability and is too vague for the purposes for which it was intended [45].
As to whether TiO2 is dangerous to human health, mixed results have been reported in the literature. In Nanotechnology: Health and Enviromental Risks, Jo Anne Shatkin concludes that “[t]he available data do not appear to be sufficient at present to derive quantitative hazard assessment for nano-TiO2 or for nanomaterials in general” [46]. Similarly, Deb Bennett-Woods notes in Nanotechnology: Ethics and Society that “… sunscreens using nanoparticles of titanium dioxide have been on the market for some time and there is evidence that particles cannot penetrate otherwise healthy skin to a depth that would allow absorption into the body” [25]. Nevertheless, both authors state the need for further research in this area. The problem with sunscreens is that they are not always used in ideal conditions, and taking this factor into account would affect the results of toxicity studies. For example, the users are not limited to healthy individuals, and sunscreens are often used on abnormal skin. In addition, Thomas Faunce and his colleagues note that when there is a lack of data, as well as evidence that is contradictory, there is a danger that the precautionary principle becomes only “a formula for doing nothing” [45]. Thus, from the perspective of environmental hazards and nanotechnology, there is strong need to develop other conceptual tools to assist in risk assessment and ethical evaluation in regulating the research and development of new consumer applications. With a different approach, say Faunce and his colleagues, TGA's decision that those sunscreens including engineered nanoparticles such as TiO2 and ZnO do not require new testing because they are considered the equivalents of their counterparts might have had different results [45].