The precautionary principle has acquired a firm place in the governance of modern society. It guides decision makers faced with risks, scientific uncertainty, and public concerns. It allows them to adopt precautionary measures even when scientific uncertainties about environmental and health impacts of new technologies or products remain. However, it is also a very debated principle, in particular with respect to its influence on innovation.Footnote 1

On the one hand, the precautionary principle is seen as a tool that helps scientists, innovators, policy makers, politicians, and societal organizations to reflect on which technologies need to be developed, which threshold of damage can be allowed and which level of uncertainty is acceptable to society.Footnote 2 As such, the principle functions as a theoretical construct that has created, in many different fields, a common language through which common concerns could be tackled.

As Gee argues, in the face of uncertainty, ignorance and complexity, and wider public engagement, societies could pay attention to the lessons of past experience and use the precautionary principle, to anticipate and minimize many future hazards, whilst stimulating innovation. As the case studies in the 2013 Report on Late Lessons from Early Warnings have shown, the timely use of the precautionary principle can often stimulate rather than hamper innovation, in part by promoting a diversity of technologies and activities, which can also help to increase the resilience of societies and ecosystems to future surprises.Footnote 3

On the other hand, the precautionary principle has been criticized as vague, incoherent, unscientific, arbitrary and the like.Footnote 4 The precautionary principle came under attack academically especially from 2005 onwards, when Cass Sunstein portrayed it as incoherent and lacking any orientation in his ‘laws of fear’.Footnote 5 Sunstein argues that risks exist on all sides of social situations, and that precautionary steps may create dangers of their own. Precautionary measures to reduce one risk may induce side-effects or so-called risk–risk trade-offs, such as increases in other countervailing risks. Therefore, Sunstein argues that in a world of risks on all sides, the precautionary principle points nowhere.Footnote 6 Moreover, critics argue that precautionary measures may be costly, and worry that measures to restrict new technologies may actually inhibit innovation.Footnote 7

Recent times have seen the rise of ‘responsible research and innovation’ (RRI), indicating that innovation and precaution can go hand in hand. RRI can be defined as a “transparent, interactive process by which societal actors and innovators become mutually responsive to each other with a view on the (ethical) acceptability, sustainability and societal desirability of the innovation process and its marketable products.”Footnote 8 It represents, therefore, the ongoing process of aligning research and innovation to the values, needs and expectations of society,Footnote 9 addressing the observation that innovation—as a goal in itself—does not always lead to results that are beneficial to society as a whole or else may be accompanied by negative side effects.Footnote 10

With this in mind, the aim of this Chapter is to increase understanding of the perceived tension between the precautionary principle and innovation, by examining how the precautionary principle is applied in EU law and by the EU courts. This Chapter is based on research carried out in the context of the EU-funded project entitled REconciling sCience, Innovation and Precaution through the Engagement of Stakeholders (RECIPES).Footnote 11 RECIPES is based precisely on this idea that the responsible application of the precautionary principle and the consideration of innovation aspects do not necessarily contradict each other. Building on this idea, the RECIPES project aims to reconcile and align science, innovation, and precaution by developing tools and guidelines to ensure that the precautionary principle is applied while still encouraging innovation. The RECIPES project is working closely with different stakeholders through interviews, workshops, and webinars.Footnote 12

This Chapter is structured as follows. In Section “Introduction”, we briefly outline how the precautionary principle is implemented in the EU. We discuss in particular the Commission Communication on the Precautionary Principle of 2000, as this document aims to give guidance on how to apply the precautionary principle at EU level.

In Section “The Precautionary Principle in EU Law”, we discuss how the precautionary principle is applied in practice. First, we examine its practical application since 2000 by the EU institutions in legal acts. Taking a bird’s-eye perspective, we examine whether and how the precautionary principle is explicitly applied in EU legal acts, and whether—and to what extent—the guidelines that were developed by the European Commission in its Communication have been applied. We do this by means of a literature review and an empirical study looking at all legal acts that mention the term precautionary principle.

Section “Application of the Precautionary Principle Since 2000 by the EU Institutions in Legal Acts” focuses on how the EU courts apply the precautionary principle in case law. As will be set forth below, the courts visibly struggle with this goal, and certain inconsistencies have arisen.

Section “Application of the Precautionary Principle by the European Courts in Court Rulings from 2000 to 2019” provides some concluding remarks and will elaborate in particular on the difficulties experienced by the EU courts in reviewing precautionary measures and dealing with science and scientific uncertainty.

The Precautionary Principle in EU Law

In 1992, the Maastricht Treaty formally introduced the precautionary principle within the then EC Treaty as a principle of environmental law and policy. Article 130(2) EC Treaty (now Article 191 (2) TFEU) stipulated that the EU’s environmental policy was to be based on inter alia the precautionary principle. It also provided that “environmental protection requirements must be integrated into the definition and implementation of other Community policies.”Footnote 13

Today the precautionary principle is generally recognized to be a principle of EU law.Footnote 14 However, Article 191(2) of the Treaty on the Functioning of the European Union (TFEU) does not provide a definition of the precautionary principle. Instead, it states:

Union policy on the environment shall aim at a high level of protection taking into account the diversity of situations in the various regions of the Union. It shall be based on the precautionary principle and on the principles that preventive action should be taken, that environmental damage should as a priority be rectified at source and that the polluter should pay.

In order to provide guidance on the application of the precautionary principle in further EU law-making, the European Commission issued a non-binding Communication on the Precautionary Principle in 2000.Footnote 15 The Commission does not provide a definition of the precautionary principle in this Communication. Rather, the Communication sets out some constituent elements of the precautionary principle. It intends to provide guidance but not to prescribe “the final word, rather, the idea is to provide input to the ongoing debate both at Community and international level.”Footnote 16 As with other general notions contained in EU legislation, the Communication sees European decision makers—and ultimately the courts —as responsible for elaborating the details of its application.Footnote 17

Accordingly, the Commission describes the situations in which the precautionary principle should be applied:

In those specific circumstances where scientific evidence is insufficient, inconclusive or uncertain and there are indications through preliminary objective scientific evaluation that there are reasonable grounds for concern that the potentially dangerous effects on the environmental, human, animal or plant health may be inconsistent with the high level of protection chosen for the Community.Footnote 18

Important hereby is that the Commission requires the presence of “reasonable grounds” for considering “potentially dangerous effects.” However, crucial terms, such as “scientific uncertainty” are left undefined.Footnote 19

The Communication draws an important distinction between, on the one hand, the decision to make use of the precautionary principle, i.e., the factors that trigger the application of the precautionary principle, and, on the other hand, the decision as to which kind of precautionary measures are to be adopted in each case and under which conditions.Footnote 20 Both decisions are eminently political by nature, depending on the level of risk that society is willing to accept, but they must, however, be based on scientific evidence.

With respect to the factors that may trigger the principle, the Communication states that such triggering “presupposes that potentially dangerous effects deriving from a phenomenon, product or process have been identified, and that scientific evaluation does not allow the risk to be determined with sufficient certainty.”Footnote 21

This sentence echoes the definition of the principle established by the European Court of Justice (or seen as such by the legal doctrine) in the 1996 BSE case, which referred to the circumstances under which the principle could be triggered (see below).Footnote 22 The Commission insists that, in any event, the principle cannot be invoked in order to justify the adoption of arbitrary decisions, and the decision should be based on the strongest possible scientific evaluation.Footnote 23

As such, the Communication provides three prerequisites for invoking the precautionary principle: the identification of possible negative effects, the performance of a scientific evaluation and the existence of scientific uncertainty.Footnote 24

Hence, some form of scientific evaluation or analysis is mandatory; the fact that in cases of scientific uncertainty no full risk assessment can be carried outFootnote 25 (and hence no scientific consensus can be established) does not preclude invocation of the precautionary principle. Hypothetical concerns are not sufficient to trigger the precautionary principle. Grounds for concern that can trigger the precautionary principle are limited to those that are plausible or scientifically tenable. These concerns are based on empirical input and/or modelling outputs that lead to the plausible scientific hypothesis that serious harm appears possible. In the Pfizer caseFootnote 26 (see below), for example, the European General Court required “as thorough a scientific risk assessment as possible, account being taken of the particular circumstances of the case at issue.”Footnote 27

Most notably, the Communication states that risk assessment consists of four components, namely hazard identification, hazard characterization, appraisal of exposure and risk characterization, and that an attempt to complete those four steps should be performed before any decision to act is adopted.Footnote 28 The risk assessment can give policy makers a more concrete idea of the extent of uncertainty and the means by which it might eventually be solved. In that regard, the Communication prescribes that due attention should also be paid to advice given by a minority fraction of the scientific community, provided that the credibility and reputation of this fraction are recognized.Footnote 29

In a second step, the Communication elaborates on the types of measures to be adopted once the decision to invoke the precautionary principle is taken. In that regard, it specifies from the outset that applying the precautionary principle does not necessarily lead to measures to be designed to produce legal effects that are open to judicial review. A broad range of measures are conceivable, such as funding research programs, informing the public about the potential risk surrounding a certain product or substance, or even in some cases a decision not to take action at all.Footnote 30 Furthermore, the Commission establishes guidelines in relation to those precautionary measures, to be followed by policy makers, comprising six components:Footnote 31

First, the Communication provides that precautionary measures should be proportional to the chosen level of protection.Footnote 32 This does not mandate achieving the unrealistic goal of a ‘zero-risk’ situation; nevertheless, under certain circumstances, the level of uncertainty is such that drastic measures such as bans may be imposed.

Second, the measures should be non-discriminatory in their application.Footnote 33

Third, especially where it proves impossible to adequately characterize the risk due to factors such as lack of data, the measures should be consistent in scope and nature with similar ones already taken in equivalent areas in which all scientific data are available.Footnote 34

Fourth, where appropriate and possible, the Communication states that a cost–benefit analysis should precede the adoption of proposed measures, which implies weighing both economic and non-economic concerns when considering their consequences.Footnote 35 In that regard, the Communication specifies that, in line with the Court’s case law, the protection of health must take precedence over economic considerations. Once again, having added that any such analysis should only take place “where appropriate and possible” implies that this is a decision for policy makers.Footnote 36

Fifth, the measures should be subject to review in the light of new scientific data. This implies, on the one hand, that even though resulting measures are only intended to be provisional, they should not be revoked until the underlying uncertainties are resolved; and, on the other hand, that scientific research ought to be continued, and that any measures should be subsequently reviewed and potentially modified in light of new scientific findings.Footnote 37

As a final guideline on the adoption of precautionary measures, the Communication prescribes that the latter should be capable of assigning responsibility for producing the scientific evidence necessary for a more comprehensive risk assessment.Footnote 38 This is the question of to whom the burden of proving the safety of a product, substance or process should be assigned. In that regard, the Commission indicates that in cases where approval mechanisms were established prior to the development of a product, the burden of proof was placed, a priori, on the manufacturer. Prior approval schemes are common and uncontroversial precautionary measures among EU Member States and also third countries. Despite involving burdensome procedures, they give producers an opportunity—before bringing a product or substance to market—to reconsider whether to proceed with it. If a producer goes through the entire process and its product is ultimately recognized as being safe and commercialized, it benefits from a situation of sensible legal certainty.Footnote 39 Where no prior approval system was established, the Communication prescribes that ad hoc precautionary measures could nevertheless be adopted with the effect of reversing the burden of proof onto the producer. According to the Commission, this should not, however, constitute a general rule.Footnote 40

Although the Communication was generally welcomed by the European Council, the Council, the European Parliament, Member States and stakeholders, academic literature published in the early 2000s has been quite critical of the Communication.Footnote 41 The main criticisms of the Communication raised in the academic literature are:Footnote 42

  • The Communication does not provide a definition of the precautionary principle. Hence, it does not give proper guidance on how the precautionary principle can then best be used;Footnote 43

  • Contrary to its declared goals, the Communication does not place meaningful and effective constraints on the application of the precautionary principle. While imposing a ‘balancing’ activity in deciding whether or not to have recourse to the principle, the communication apparently tipped in favor of adopting preventive measures. Hence, it failed to set a risk threshold triggering its invocation;Footnote 44

  • It is naive to assume that decisions based on the precautionary principle can be reversed when new scientific findings become available, as this ignores the problem of technical stigma;Footnote 45

  • The Commission does not provide a means to assess and determine which hazards should be prioritized over others in considering the precautionary principle;Footnote 46

  • The Communication does not address the problematic issue of risk–risk trade-offs;Footnote 47

  • Although in principle the Commission favors cost–benefit analysis, it also argues that this should consider not only the costs to the EU but also those associated with a number of non-economic considerations such as public acceptability, leaving the Commission plenty of vague language for interpretation.Footnote 48

Importantly, the literature has criticized the Commission’s view that the precautionary principle “pertains to risk management and not also to risk assessment.” In this context, we agree that the precautionary principle should be seen as a general governance principle employed throughout the overall process of framing, assessment, evaluation, and management.Footnote 49

In the next section, we examine how the EU institutions have applied the precautionary principle in practice, and whether the Communication has been followed.

Application of the Precautionary Principle Since 2000 by the EU Institutions in Legal Acts

As a baseline for the RECIPES project, an extensive review was conducted of whether and how the precautionary principle has been referred to in the adoption of legal acts since 2000.Footnote 50

In order to understand how the precautionary principle is used in practice by the EU institutions in legal acts, the context of its use must first be understood. Therefore, we first examined how many legal acts employ or refer to the precautionary principle. To this end, we conducted an advanced search on the Eur-Lex portal for the term [precautionary principle] in EU legal acts.

The search returned a total of 135 legal acts, of which 94 (40 regulations, 27 directives and 27 decisions) remained in force in July 2019 which then formed the basis of our further analysis.

A few observations need to be made concerning the number of acts. Firstly, it is clear that the total number of acts found (i.e., 135 acts in a period of 19 years, with 94 of these remaining in force) is quite small in view of the fact that, annually, the EU legislator currently adopts approximately 150 legislative acts and the Commission almost 2000 executive acts (both delegated and implementing). Here, it is important to underline that we did not look into acts that may apply precautionary approaches without explicitly mentioning the precautionary principle. This would be particularly relevant for acts concerning food safety (because of the General Food Law) and the environment (in view of Article 191 TFEU). Consequently, in practice, there may be more situations in which the precautionary principle is being applied. It is therefore acknowledged that the bird’s-eye perspective, and hence the search for the term [precautionary principle] in legal acts, is an important starting point but that further research is needed to precisely grasp the actual application of the precautionary principle in EU legal acts.

Nevertheless, on the basis of these data it can be observed that, although the precautionary principle is applied to a broad range of topics, it remains primarily a feature of the traditional sectors such as environmental, consumer and health protection. This coincides with the Commission’s Communication.Footnote 51 Academic research, moreover, shows that for the invocation of the precautionary principle it matters which Directorate General (DG) is responsible for addressing the risk issue in question. For example, DG Environment has been found to be more willing to propose precautionary policies than DG Industry.Footnote 52

Importantly, the research also showed that, where the precautionary principle is used as a guiding principle, the reasons for doing so are often poorly explained. Moreover, only six of the legal acts provide a definition of the precautionary principle. The first notable attempt to define the precautionary principle was made in the General Food Law in 2002. Article 7 of this Regulation emphasizes the use of the precautionary principle in response to scientific uncertainty and as part of “risk management.” It also clearly establishes the provisional nature of precautionary measures, by stating that they are adopted “pending further scientific information for a more comprehensive risk assessment” (Art. 7(1)) and are subject to review “within a reasonable period of time” (Art. 7(2)). The trigger for the use of the principle, specified here as “possibly harmful effects on health,” must necessarily remain imprecise. This corresponds to the definition and criteria established in the Commission’s 2000 Communication.

Article 7, General Food Law (Regulation 178/2002)

  1. 1.

    In specific circumstances where, following an assessment of available information, the possibility of harmful effects on health is identified but scientific uncertainty persists, provisional risk management measures necessary to ensure the high level of health protection chosen in the Community may be adopted, pending further scientific information for a more comprehensive risk assessment.

  2. 2.

    Measures adopted on the basis of paragraph 1 shall be proportionate and no more restrictive of trade than is required to achieve the high level of health protection chosen in the Community, regard being had to technical and economic feasibility and other factors regarded as legitimate in the matter under consideration. The measures shall be reviewed within a reasonable period of time, depending on the nature of the risk to life or health identified and the type of scientific information needed to clarify the scientific uncertainty and to conduct a more comprehensive risk assessment.

As this is one of the rare instances in which a clear definition of the precautionary principle is spelled out, it is not surprising that references to the General Food Law are also contained in other legal acts. This is the case in two other food-related Regulations as well as the Regulation on plant protection products.Footnote 53

Besides this, the precautionary principle is identified only in one other act of general application revealed by our search: Article 2 of a Council Decision on the Protocol on the Implementation of the Alpine Convention in the field of transport (Transport Protocol). Compared to the definition laid down in the General Food Law, the threshold for triggering the precautionary principle seems slightly higher in the Transport Protocol, which makes reference to “serious irreversible effects on the health and the environment,” albeit indicating that this also means “potential harmfulness.” The General Food Law, in contrast, departs from “potential harmful effects on health.”

With regard to the requirement of scientific uncertainty, both legal acts show similarities. The Transport Protocol refers to situations where “research has not yet strictly proven the existence of a cause-and-effect relationship” between substances and potential harm, whereas the General Food Law mentions that “scientific uncertainty persists.” The measures to be taken in such situations are those “intended to avoid, control or reduce effects” of such harm (Transport Protocol) or “risk management measures” necessary to ensure health protection (General Food Law).

The formulation of the action to be taken differs slightly. Whilst the Transport Protocol links with the triple negative formulation of the Rio Declaration in stating that measures “should not be postponed” by reference to uncertainty, the General Food Law holds that measures “may be adopted.”

Moreover, the General Food Law clearly states that the measures are of a “provisional” nature and “pending further scientific information”; in contrast, no such indication is given in the Transport Protocol definition, although this is one of the requirements foreseen in the 2000 Communication.

It can therefore be said that there is no single definition of the precautionary principle in EU legal acts. The EU General Food Law regulation is quite exceptional in that it expressly defines the precautionary principle for application in that sector. EU environmental legislation provides no equivalent definition, although the TFEU (Treaty on the Functioning of the European Union) directly refers to the precautionary principle as a basis for EU environmental policy. This has left the precautionary principle open to interpretation within the environmental policy area.

On the one hand, this is advantageous as it allows for flexibility and the possibility to adapt to individual needs of environmental problems. Commentators have generally viewed the lack of general definition of the precautionary principle at EU level positively, as the principle’s application differs across the range of policies and must be context specific. Quite evidently, this has led to different approaches and interpretations. This is why both the literature and the Commission, instead of giving a firm definition, prefer to speak of the “constituent parts”Footnote 54 of the precautionary principle.

Whilst it is neither necessary nor possible to strive for a general legal definition of the precautionary principle in EU law, it is of crucial importance that procedures for the application of the principle, such as the ways in which risk assessments are performed, the transparency in dealing with uncertainties, and how different strengths of evidence for action are evaluated and chosen, are similar and predictable.Footnote 55

Our analysis of legal acts reveals, however, that the invocation of the precautionary principle is diverse and seems to leave gaps with regard to a precise definition and application of the principle. Scholarly analyses confirm these findings. Garnett and Parsons reviewed a small sample of Directives and Regulations and concluded that the precautionary principle was applied differently in EU law, and with very little consistency across cases regarding the conditions for taking precautionary action and the basis for imposing regulation.Footnote 56 Their review of a limited numbers of legal acts (4 Regulations, 4 Directives and 3 Decisions of the EU legislators and the Commission) reveals that application of the precautionary principle varies in strength from weak to moderate and strong precaution.

The above shows that the guidelines laid down in the Commission’s Communication are not followed consistently in legal practice. These findings could cast doubt on the impact of the 2000 Communication. Löfstedt, for example, argues that the Communication has been little used in practice, and calls for a review of the Communication.Footnote 57 These findings, moreover, largely correspond to those of a study on the use of the precautionary principle in EU Environmental policies performed by Milieu for the European Commission in November 2017. The latter study, for example, shows that certain aspects, such as methodologies for assessing risk and the question of when precautionary action is required, vary across the different environmental sectors. This can be explained by the differing, content-specific approaches taken.Footnote 58 However, as indicated above, a coherent application of procedures for the application of the principle, such as the ways in which risk assessments are performed, transparency in dealing with uncertainties, and how different strengths of evidence for action are evaluated and chosen, are of fundamental importance to avoid tensions between the precautionary principle and innovation.

We can also refer here to the Ombudsman’s view of the precautionary principle as a principle of good administration.Footnote 59 This consideration may link up, on one side, with the acceptance of a lack of a general legal definition of the precautionary principle in EU law and, on the other side, with the view that one should look more closely into establishing similar and predictable procedures for its application.

Application of the Precautionary Principle by the European Courts in Court Rulings from 2000 to 2019

Besides examining how the precautionary principle has been referred to in the adoption of legal acts since 2000, the RECIPES project also examined how the European Court of Justice has dealt with the precautionary principle. In this regard, we performed a literature review, a review of seminal Court cases and a quantitative analysis.

As a preliminary matter, it should be noted that the Court of Justice of the European Union (CJEU) interprets EU law to ensure it is applied consistently across all EU Member States, and settles legal disputes between national governments and EU institutions. It can also be used by individuals, companies, or organizations to take action against an EU institution if they feel it has infringed their rights. The CJEU is divided into two courts: the Court of Justice, which deals with requests for preliminary rulings from national courts, actions for annulment and appeals; and the General Court, which rules on actions for annulment brought by individuals, companies and, in some cases, governments of EU Member States.Footnote 60

Definitions of the Precautionary Principle

As the 2000 Communication did not provide a definition of the precautionary principle, CJEU case law is crucial in determining when, how and by whom the precautionary principle may be relied upon in the EU legal order.Footnote 61 However, the courts visibly struggle with this role and certain inconsistencies have arisen.

References to the precautionary principle in case law of the Court of Justice and the General Court between 2000 and 2019 are generally considerably more detailed than references in legal acts. In total, the Eur-Lex search for the expression [precautionary principle] yielded 147 results. This includes judgments by both the General Court and the Court of Justice in procedures under articles 260, 263, 267 and 340 TFEU. The codes used by Eur-Lex indicate that the subject areas covered in these judgments are similar to the findings in legislation. The codes for environment (70 instances), approximation of laws (53), agriculture and fisheries (41) as well as health (21) were used most often.Footnote 62

The courts have made important contributions to the understanding of the precautionary principle in milestone cases, namely: Alpharma (2002), Artegodan (2002), Pfizer (2002), Solvay Pharmaceuticals (2002), Paraquat (2007), Gowan (2009), SPCM (2009), Afton (2010), Bayer CropScience (2018) and Confederation Paysanne (2018). We refer to these cases to show tendencies in the EU courts’ application and interpretation of the precautionary principle.

The courts have given various definitions of the precautionary principle, which have been formalized over time. Generally, we can observe that the courts use three different formulations of the precautionary principle, one of which is further differentiated depending on whether the principle is invoked by the Commission or a Member State.

Above, we already reported on the Court’s definition of the precautionary principle to be applied by the EU institutions in the BSE case, which has been repeated as a standard formulation in many other cases:

Where there is uncertainty as to the existence or extent of risks to human health, protective measures may be taken without having to wait until the reality and seriousness of those risks become fully apparent.Footnote 63

A similar formulation is used for the Member States:

It is clear that such an assessment of the risk could reveal that scientific uncertainty persists as regards the existence or extent of real risks to human health. In such circumstances, it must be accepted that a Member State may, in accordance with the precautionary principle, take protective measures without having to wait until the reality and seriousness of those risks are fully demonstrated.Footnote 64

In other cases, the courts stated that:

The precautionary principle allows the adoption of provisional risk management measures necessary to ensure a high level of health protection when, following an assessment of available information, the possibility of harmful effects on health is identified but scientific uncertainty persists [pending further scientific information].Footnote 65


Where it proves to be impossible to determine with certainty the existence or extent of the alleged risk because of the insufficiency, inconclusiveness or imprecision of the results of studies conducted, but the likelihood of real harm to public health persists should the risk materialise, the precautionary principle justifies the adoption of restrictive measures.Footnote 66

These definitions consistently point to scientific uncertainty as the main factor for invoking the precautionary principle, allowing for restrictive measures. Moreover, case law that was issued after the 2000 Communication makes mention of the provisional character of the risk management measures whilst also pointing out that precautionary action may only be taken following an initial assessment of the available information. Our analysis reveals that no explicit evidence of risks is necessary in order for the regulator to rely on the precautionary principle.

Limited Judicial Review of the Precautionary Principle

We reviewed cases in which the precautionary principle was invoked, in order to define commonalities with respect to the Courts’ review of these cases. The analysis of the cases selected shows that the courts’ review is limited to a small number of potential factors. These factors can be broadly divided into three categories: first, the reasons for triggering the use of the principle; second, the considerations that the regulator must take into account in the decision-making phase; and third, the requirements that any resulting measures must comply with.

We will now discuss each of these categories.

Review of Reasons for Triggering the Use of the Precautionary Principle

First, the Courts must decide whether the invocation of the precautionary principle was justified. Here, the Court attempts to define the precautionary principle and examines the elements that justify the use of the precautionary principle. In this stage, the Court only reviews whether the conditions for applying the precautionary principle are fulfilled (i.e., the sufficiency of scientific uncertainty) and ensures that the regulator does not base its decision on purely hypothetical risks.

In the milestone case involving Pfizer, the Court of First Instance (now General Court) for the first time discussed the interpretation and the correct application of the precautionary principle and defined the conditions for triggering the application of the precautionary principle.Footnote 67

According to the judgment:

in case of scientific uncertainty as to the existence of a risk to human health, the EC institutions as well as the Member States may invoke the precautionary principle in order to adopt protective measures, in spite of the fact that a proper risk assessment showing conclusive scientific evidence cannot be conducted.Footnote 68

More specifically, the factors for triggering the precautionary principle are further described with regard to two different elements. First, the requirement that the risk on which the action is based may not be hypothetical is emphasized. As has been demonstrated previously, this is one of the elements the Court is indeed willing to review.

Second, the Court moreover applies the definition of the precautionary principle to very specific authorization procedures and emphasizes above all the need for ‘solid evidence’. Thus, the Court requires sufficient evidence in order to conclude that there is insufficient scientific information about the prevalence of certain risks. This is what van Asselt and Vos have referred to as the ‘uncertainty paradox’.Footnote 69 Whilst an insufficient amount of evidence can, in principle, be a reason for the Court to review decisions, this had an effect in the decisions analyzed only where procedural errors were made. The exact level of uncertainty needed is difficult to assess and therefore, in practice, only subject to a very limited review.

In procedural terms, it is important for the regulator to conduct a risk assessment in order to provide the required level of ‘solid evidence’. In practice, however, this requirement is not always fulfilled. In several cases (Alpharma, Solvay) no risk assessment was performed, and the Court did not reprimand the Commission or the Council for not conducting a risk assessment. Instead, the Court “acted as a super risk assessor,” whereas it ought to have determined whether the risk manager conducted a risk assessment and whether this was done according to the procedural requirements. In its place, the Court constructed uncertainty as the absence of full safety.Footnote 70

The academic literature emphasizes that other cases show the same lack of a proper risk assessment.Footnote 71 In Afton, the Commission did not conduct a risk assessment to determine the negative impact of MMT (methylcyclopentadienyl manganese tricarbonyl, a fuel additive) on pollution abatement techniques.Footnote 72 In Bayer CropScience, the Court accepted expert consultations as a sufficient form of risk assessment.Footnote 73 Furthermore, both Alemanno and Zander argue that in both the Paraquat and Gowan court cases the European court has supported the use of the precautionary principle to ban substances without robust scientific evidence of their potential effects (and in Paraquat the Court even found that the Commission must act in a precautionary manner).Footnote 74

However, in various cases the Court states that:

In the domain of [human health], the existence of solid evidence which, while not resolving scientific uncertainty may reasonably raise doubts as to the safety of a substance justifies, in principle, [the refusal to include that substance…]. The precautionary principle is designed to prevent potential risks.Footnote 75

The Court has therefore repeatedly held that:

The risk assessment cannot be based on purely hypothetical considerations.Footnote 76

Van Asselt and Vos argue that, in Pfizer, the Court equated scientific uncertainty with diverging opinions and thereby constructed its own definition of uncertainty.Footnote 77 They highlight the possibility that, in this manner, the precautionary principle might be applied whenever one qualified scientist holds a diverging opinion.Footnote 78

Janssen and van Asselt (2013)Footnote 79 examined post-Pfizer case law to determine whether the problematic ruling of the Court in Pfizer had set a precedent. They identified several tensions and inconsistencies in the Court’s rulings on Pfizer, Alpharma, Artegodan and Solvay Pharmaceutical (all during 2002), both with respect to the prerequisites for invoking precautionary principle and also the measures eventually taken. Furthermore, Janssen and Rosenstock criticize the Court’s lack of vision on how to deal with uncertainty and precaution.Footnote 80 Janssen and van Asselt hold that, in Pfizer, the General Court used scientific disagreement as a way of constructing uncertainty about the risk in question. The Court referred to diverging opinions between experts, which was subsequently used to legitimize the application of the precautionary principle.Footnote 81

Moreover, in Alpharma, uncertainty was not only constructed through a lack of scientific consensus; moreover, the Court also argued in terms of analogy with other antibiotics. In this case, there were no risk assessments performed on the specific substance bacitracin zinc. The Court, however, ruled that “all antibiotics and all nitrofurans have similar characteristics and should be treated in the same way.”Footnote 82 As Janssen and van Asselt argued, this argumentation entails that substance-specific characteristics are no longer relevant to risk assessments, and that commonalities suffice.Footnote 83 Analogy was also applied in the Solvay case involving the antibiotic Nifursol and subsequently in the cases of both Gowan and Bayer CropScience. Janssen and Rosenstock argue that, with this approach to establishing uncertainty, the precautionary principle could easily become a tool to prohibit marketing of products.Footnote 84

Review of Considerations Taken Into Account in the Decision-Making Phase

Second, the decision-making process itself requires a complicated assessment of scientific data on the one hand and societal preferences on the other, both of which are difficult issues for a court to review. The EU courts indeed declare in many cases their review to be limited to manifest errors.

The courts operate in this decision-making phase under the precautionary principle another set of formulations. Interestingly, the courts state in various cases that the precautionary principle can ‘require’ the institutions to take action. This is in sharp contrast to other cases in which the courts held that the precautionary principle “may warrant the adoption of a restrictive measures by an institution” but “does not require it to do so.”Footnote 85 The Commission has also stated that, in its view, the precautionary principle “does not… oblige the Community institutions to follow all scientific opinion without any margin for assessment.”Footnote 86

In other cases, the courts’ formulations are variants of the same starting point: they state that the regulator must follow certain steps when applying the precautionary principle. The regulator must identify the risk and then conduct an assessment relying on relevant data. In this regard, the General Court views that risk management measures can be taken on the basis that:

Within the process leading to the adoption by an institution of appropriate measures to prevent specific, potential risks to public health, safety and the environment by reason of the precautionary principle, three successive stages can be identified: firstly, identification of the potentially adverse effects arising from a phenomenon; secondly, assessment of the risks to public health, safety and the environment which are related to that phenomenon; thirdly, when the potential risks identified exceed the threshold of what is acceptable for society, risk management by the adoption of appropriate protective measures.Footnote 87

This is also confirmed by both courts, where they state that:

The correct application of the precautionary principle presupposes, first, identification of the potentially negative consequences for health of the substances or foods concerned, and, second, a comprehensive assessment of the risk to health based on the most reliable scientific data available and the most recent results of international research.Footnote 88

These step-by-step conditions offer the courts another, much clearer, possibility for review. Whilst substantive decisions are difficult to review, these seemingly clear procedural issues can be assessed in a comprehensive way and have, as seen in the BASF case, led the General Court to annul a Commission decision.Footnote 89

Importantly, the General Court views that measures to protect human health and safety and the environment take precedence over economic interests.

The precautionary principle is a general principle of EU law requiring the authorities in question, in the particular context of the exercise of the powers conferred on them by the relevant rules, to take appropriate measures to prevent specific potential risks to public health, safety and the environment by giving precedence to the requirements related to the protection of those interests over economic interests.Footnote 90

Review of the Requirements that Measures Resulting from the Precautionary Principle Must Comply With

The measures resulting from the decision-making process are mainly reviewed by the courts to ensure that they are proportional and do not aim, unrealistically, for a “zero-risk approach.” The courts impose clear conditions: non-discrimination, proportionality and objectivity are central in the judicial review of decisions: “Such measures must not be allowed unless they are non-discriminatory, proportional and objective.”Footnote 91

Moreover, the courts repeatedly emphasized that the regulator should not aim for a “zero-risk approach.” Studies have confirmed that proportionality is subject to a more thorough review than other criteria, such as the need for new scientific data.Footnote 92 Rogers highlights that this should not be surprising, considering that the topic of proportionality has been long discussed in European circles, while the fact that precautionary actions should be subject to review has, to date, never been tested in the courts.Footnote 93 The proportionality principle is well established in EU law, and the courts have considerable practice in applying it,Footnote 94 so much so that, in Pfizer, the fourth criterion (action should be subject to costs and benefits of the proposed action) was effectively subsumed by the courts under the proportionality test.Footnote 95

Furthermore, whilst the courts emphasize that a zero-risk policy is not acceptable, it has been repeatedly criticized on this issue. Another requirement with regard to the outcome, which is clearly mentioned in the Communication but significantly less subject to judicial review, is the requirement to review the measure in light of new scientific data. It appears that in various cases the courts have ignored the temporary nature of precautionary measures. However, such re-evaluations are necessary to prevent precautionary measures becoming permanent contrary to the indications of new scientific evidence. Instead of demanding a substantive review of the latest scientific findings, the General Court found in SolvayFootnote 96 that an administrative review is sufficient when deciding on precautionary measures. Consequently, “by not insisting on a new risk assessment of the substances, the Court disregards the temporary character of the precautionary principle.”Footnote 97

The General Court’s ruling in the Artegodan case, however, differed from that in Solvay. The General Court explicitly argued that old data that had been used in previous assessments may not constitute a sufficient basis upon which to establish scientific uncertainty in the present.Footnote 98

Conclusions on the European Courts’ Application of the Precautionary Principle

In sum, the academic literature reveals several inconsistencies in the courts’ rulings in dealing with uncertain risks, which has led to several problematic patterns in which the precautionary principle is effectively utilized as a tool for risk management. The academic literature details a number of recurring issues.

First, with respect to the prerequisites for invoking the precautionary principle, the EU courts in some cases define uncertainty simply as differing scientific opinions, or a lack of consensus between experts. This is a delicate issue that could open up the prospect of protectionism, since differing scientific opinions can be found in many scenarios involving uncertain risks. Therefore, requirements as to the production of such scientific opinions that form the basis of regulatory measures, which experts participate, etc., become of key importance here.

Next, in various cases, the courts have accepted the use of the precautionary principle in the absence of proper scientific evidence. The courts ruled that the possibility of a risk, the absence of zero risk, or the lack of information establishes uncertainty and risk, and is therefore sufficient legal basis for precautionary measures. These are very low thresholds for invoking precautionary measures, since any form of uncertainty requires assessment of risk (which may have positive or negative outcomes). In some cases, the academic literature has criticized the courts for seemingly accepting even inadequate risk assessments.Footnote 99 Moreover, to various extents in the different cases: no risk assessments were performed by independent bodies, risk assessments were ignored, and analogy between substances and expert consultations were deemed sufficient.Footnote 100

It has been argued that the review of proportionality is often insufficiently strict.Footnote 101 Moreover, it has been asserted that the courts have also disregarded the temporary nature of risk measures by failing to insist on new risk assessments or ignoring new information, despite the requirement that each case must be reviewed based on the latest scientific evidence available. Rogers so holds that EU courts could make a provisional or interim order pending further research but, so far, they have not done so.Footnote 102

Comparing the courts’ case law with the Commission 2000 Communication, we can note that the courts do pay attention to the 2000 Communication, but—from analyzing the milestone cases—not consistently. Consequently, it appears that, in particular, the requirements for a robust risk assessment or cost–benefit analysis are not met in all cases.

Furthermore, the sample analyzed in this work is too small to provide definite conclusions, but it seems that in most cases the courts agree with a ban or upholds restrictions. It seems that the courts generally adopt a moderate to strong interpretation of the precautionary principle. These findings support those in the academic literature, in that it seems that the 2000 Communication does not provide sufficient guidance on the application of the precautionary principle. On the other hand, it should be remembered that the 2000 Communication is a non-binding guidance document and that the courts are not bound to apply the criteria proposed by the Commission.

Concluding Remarks

Our contribution highlights that the precautionary principle is employed as a principle of EU law, while there is the lack of a single definition. Turning to the practical application of the precautionary principle in the EU, our legal analysis reveals that, consequently, the criteria for precautionary action, as described in the Commission’s Communication on the precautionary principle, are not applied consistently by EU policy makers or the EU courts.

The lack of a single definition of the precautionary principle in EU law can be viewed as advantageous, as it leaves ample room for flexibility and establishing ad hoc solutions to context-specific problems. Quite evidently, this has led to different approaches and interpretations. Moreover, it leaves the EU courts with the difficult task of reviewing precautionary measures adopted by the EU institutions. Although these courts have formulated definitions and requirements for applying the precautionary principle, it is also clear that at times they are inconsistent and visibly struggle to review measures involving scientific uncertainty. Where, paradoxically, regulators tend to ask for greater scientific certainty in resolving cases of scientific uncertainty, science increasingly appears in the courtroom.Footnote 103 Yet, unless there are procedural mistakes or manifest errors of assessment, the EU courts have often been quite reluctant to annul precautionary decisions in view of the large discretion the Commission has in such cases.

To be sure, decisions involving the precautionary principle must often strike a delicate balance between risk assessments on the one hand and societal risk tolerance on the other. In addition to reasons of balance of powers and the rule of law, it is therefore quite understandable that the courts leave the EU legislator and the Commission much discretion to do so.Footnote 104

Furthermore, the courts seem largely disinterested in reviewing the supposedly temporary nature of precautionary measures. Some judgments seem to overlook the “dynamics of science,” e.g., new scientific evidence questioning prior judgement. The requirement set forth in the Commission’s Communication—that precautionary measures should be provisional, pending a reduction in the scientific uncertainty—is still to be seriously addressed by the EU courts.Footnote 105

Ultimately it is important to acknowledge the limits of science in complex judicial decision-making and to realize that “any effort to bring better science into the courtroom must respect the courts’ constitutionally specified role,” “even if doing so means, from time to time, what is, from a scientific perspective, an incorrect result.”Footnote 106 Hence, judges should remain judges; they should not become “amateur scientists.”Footnote 107 Courts should therefore leave responsibility for science-based decision making to decision makers, as advised by scientists.

In the EU context, it might be helpful for decision makers (the EU legislator, the Commission, or the Member States) to receive more guidance, perhaps in the form of a revised Commission communication. Such a revision could clarify—without losing track of the need for flexibility to adapt to the specific needs of individual problems—the role of science, and give guidance to regulators on how to deal with scientific uncertainty in decision making. This could be particularly helpful in cases where such certainty cannot presently be provided by current scientific knowledge in avoiding a quest for ever greater scientific certainty, thereby easing a perceived tension between precaution and innovation.

This is of particular importance in striking an appropriate balance between, on the one hand, concerns for health, safety, and environmental protection and, on the other hand, economic interests. It is clear that the intricacies of dealing with precautionary measures involving science and scientific uncertainty in courtrooms remain delicate and require further scholarly attention.