Daan Bodson, LL.M in European Union Law, Université Panthéon-Assas (Paris 2)
Photo credit:
US Dept of Defense, via Wikimedia
Commons
Introduction
More than two
years after the WHO declared COVID-19 no longer a global emergency, its impact
is still felt. Remote work has become routine in many sectors, younger generations
speak more openly about mental health, and the pandemic has left its mark on EU
law. Faced with extraordinary circumstances, Member States adopted
extraordinary restrictions, which in turn prompted courts to revisit how
fundamental freedoms like free movement are balanced against public health.
Many of the
measures aimed at restricting the spread of the virus involved limiting the
free movement of individuals, one of the fundamental rules of the EU legal
order. When these restrictions were challenged before the EU courts, both the
ECJ and the EFTA Court delivered landmark rulings. For the first time, they
brought the precautionary principle squarely into free movement case law.
This contribution
revisits that jurisprudence and asks what it means beyond the pandemic. Since
neither court confined its reasoning to COVID-19, the question arises: can
precaution also justify restrictions in other policy fields marked by
scientific uncertainty? I argue that Nordic
Info (C-128/22, 5 Dec 2023) and LDL
(E-5/23, 21 Mar 2024) lowered the threshold for Member States to justify
restrictions under the precautionary principle, and that this reasoning can
also support measures against mental health risks from social media usage.
The case law:
Nordic Info and LDL
Setting the
stage: National measures aimed at limiting the spread of COVID-19
On December 5th
of 2023, the ECJ rendered its Nordic Info judgement, in which it ruled
on the legality of a Belgian measure banning all non-essential travel to
“red-listed countries”. These red-listed countries were designated based on epidemiological
data available at the time. The national measure was challenged by a travel
agency specializing in trips to Scandinavia. In the LDL judgement,
rendered by the EFTA Court a few months after Nordic Info, the Court
ruled on the legality of a Norwegian law requiring individuals travelling from
abroad into Norway to subject themselves to a quarantine period spent in a
specific “quarantine hotel”.
Both courts readily
classified these measures as restrictions on the free movement of persons under
the EU
Citizens’ Directive (and its extension to the EEA). This legislation,
however, allows for restrictions on grounds of public health (Art. 27 & 29),
yet sets some safeguards to these limitations, such as a right to an effective
remedy, and a proportionality check (Art. 31).
In both cases,
the main legal question thus was whether or not the restrictions were
considered proportionate. Remarkably, and for the first time in free movement
case law, both courts expressly included the precautionary principle into this
proportionality test. This novel introduction could significantly reshape the
proportionality assessment in situations where the precautionary principle
applies.
Understanding
the precautionary principle
The precautionary
principle is well-established in EU law. It regularly appears in judgments of
both the ECJ and the EFTA Court and informs many policy fields. At its core,
the principle provides a legal and policy tool for decision-makers faced with scientific
uncertainty combined with potential risks. Where evidence of harm is
insufficient, inconclusive, or uncertain, but the stakes are significant,
legislators may intervene proactively without waiting for full scientific
proof. As the ECJ stated in Nordic Info: “if there is uncertainty as to
the existence or extent of risks to human health, a Member State must be able,
under the precautionary principle, to take protective measures without having to
wait until the reality of those risks becomes fully apparent” (para. 79).
In practice, the
principle applies when there are indications of risk but no certainty about its
precise magnitude, its long-term effects, or the most effective mitigating
measures. In such cases, national or EU legislators retain discretion to
determine the level of protection they wish to guarantee. The degree of
scientific uncertainty will, however, shape the extent of that discretion: the
greater the uncertainty, the broader the space for precautionary action.
This principle
features in many fields of EU policy. The TFEU explicitly prescribes that the
principle shall guide the EU’s environmental policy. ECJ case law (e.g., C-157/96)
and legislation (e.g., regulation
178/2002) has further broadened the scope of application of the principle
to all types of risks to environmental, human, animal, or plant health.
The European
Commission’s 2000 Communication
on the precautionary principle further clarified its scope and criteria.
The Communication underlined that the precautionary principle doesn’t allow for
arbitrary restrictions. Measures must still comply with broader EU law
requirements, such as proportionality, non-discrimination, consistency,
examination of costs and benefits and dynamic review. These principles ensure
that precaution remains balanced and doesn’t overly interfere with the internal
market.
The novelty:
introduction of the precautionary principle in free movement case law
Whilst the
precautionary principle itself is far from new in the EU legal order, its
application in free movement case law in the Nordic Info and LDL
cases is new. In both cases, the courts were confronted with a situation of
scientific uncertainty: at the time, there was no conclusive knowledge about
how COVID-19 spread, how lethal it was, or which measures were most effective.
Yet Member States had to act to protect public health. Against this background,
the courts held that the precautionary principle applied, granting national
authorities wider discretion to define their own level of health protection and
to adopt restrictive measures to limit contagion.
Ordinarily, the
proportionality test for restrictions on free movement follows three steps:
-
Suitability: the measure must
be capable of achieving its stated aim.
-
Necessity: there must be no
less restrictive measure that is equally effective.
-
Proportionality stricto
sensu: the benefits of the measure must outweigh the rights it restricts.
What changed in
these cases is that the precautionary principle softened the evidentiary
demands at each stage:
-
Suitability: Instead of
requiring proof that the measure was demonstrably effective, it was sufficient
that, in light of limited scientific knowledge, the measure appeared reasonably
capable of achieving its aim.
-
Necessity: Courts did not
demand a fully substantiated comparison of alternatives. A measure passed this
step unless it was evident that another, less restrictive option would
be equally effective (Nordic Info, para. 90).
-
Proportionality stricto
sensu: In the balancing of interests, scientific uncertainty itself tipped
the scales in favor of public health. Far-reaching restrictions were upheld
even without full certainty as to their effectiveness.
In short, the
precautionary principle did not replace the proportionality test but
recalibrated it: lowering the threshold of proof and granting Member States
greater leeway when acting under conditions of scientific uncertainty.
Beyond
COVID-19: precautionary principle and digital well-being
The case law on
COVID-19 restrictions carries implications well beyond the pandemic itself.
Crucially, neither the ECJ nor the EFTA Court confined their reasoning to
emergency circumstances, and Advocate General Emiliou even stressed in his Opinion
in Nordic Info that the case had to be assessed under the “ordinary”
rules of EU law. This suggests that the interpretive shift brought by the
precautionary principle is not an exceptional tool for crisis management, but
part of the general framework for justifying restrictions on free movement.
This raises a
broader question: if precaution can justify far-reaching measures in times of
scientific uncertainty about public health, could it also apply in other fields
where risks are emerging but not yet conclusively proven? One particularly
pressing area is digital well-being. With growing evidence of the mental health
risks linked to social media and addictive algorithms, especially for young
people, the same legal reasoning could potentially empower Member States to
adopt preventive measures.
Social media,
addictive algorithms and associated mental health risks
Social media
platforms rely on algorithms that continuously predict and adapt to user
preferences. By generating personalized feeds designed to maximize engagement,
these systems keep users online longer and, in turn, increase advertising
revenues.
Growing evidence
links such addictive algorithms and the use of social media generally to
negative mental health outcomes, particularly among children and adolescents.
Users are frequently exposed to harmful content, such as unrealistic body
images, and research increasingly associates prolonged social media use with
depression, anxiety, body dysmorphia, and even suicidal thoughts.
Because social
media is a relatively recent phenomenon, the long-term effects are not yet fully
known. Scientific studies are emerging, but uncertainty remains inherent: it is
difficult, perhaps impossible, to precisely measure the long-term mental health
consequences of algorithm-driven platforms, especially for young people.
The EU has begun
to acknowledge these risks. The Digital
Services Act (“DSA”) of October 2022 introduces obligations for “very large
online platforms and search engines,” requiring them to conduct risk
assessments, explicitly covering algorithmic systems, and to implement
reasonable mitigation measures. This reflects a policy shift toward more
stringent obligations for these large platforms, aimed at enhancing, among
other things, user well-being.
The
precautionary principle: more space for Member States to act?
Despite the DSA,
Member States may wish to go further in protecting citizens’ mental health.
Insofar as measures do not interfere with harmonized EU law, Member States can
determine their desired level of protection and take adequate measures. In
practice, this could mean considering specific obligations on tech manufacturers
(e.g., better parental control tools) or even on the accessibility of devices
to minors.
National
measures in this area are likely to restrict the free movement of services, and
possibly freedom of establishment or free movement of goods. Ordinarily, such
measures would face steep hurdles, since they would need to be justified and
proportionate, which typically was a high bar. However, under the Nordic
Info and LDL rulings, Member States now enjoy wider leeway to
justify such restrictions. The introduction of the precautionary principle into
free movement law means that scientific uncertainty no longer necessarily blocks
preventive regulation.
For precaution
to apply, three conditions must be present:
-
a potential risk, including
mental health risks for humans;
-
scientific uncertainty about
its scope or effects, and
-
the absence of full proof or
consensus related to the extent of the risk and / or the most suitable
mitigating measures.
In the case of
digital well-being, these conditions seem to be met. Academic research points
to a range of mental health risks from social media use, but the extent of the
danger and the precise causal links remain unsure. Member States could take
precautionary measures in multiple forms. Even though harmonized EU legislation,
such as the DSA, bars Member States from introducing measures within this
field, some measures are still imaginable. For example, States could require phone
manufacturers to include robust parental control tools by default.
Alternatively, Member States could consider a ban on design features such as
auto-play or endless scroll for under-16s, or even impose an age limit for the
sale of smartphones (as considered
by the UK government).
The significance
of Nordic Info and LDL is that these measures no longer need
conclusive scientific proof to survive judicial scrutiny. It is enough that
they seem reasonably appropriate, and that no evident less restrictive
alternative exists. In balancing fundamental rights, the courts signaled that
precaution may tilt the scales in favor of public health, even when other
freedoms, such as free movement of services or freedom to conduct business, are
affected.
Conclusion
The COVID-19
pandemic was not only an unprecedented test for Europe’s health systems, but it
also challenged the boundaries of EU law. In Nordic Info and LDL,
the courts expanded the role of the precautionary principle in free movement, potentially
lowering the evidentiary threshold for Member States to justify restrictive
measures. Importantly, this reasoning was not tied to emergency conditions, which
opened the door for its application in other contexts.
The growing,
though inconclusive, evidence linking social media usage and addictive
algorithms to mental health issues raises the question of whether the evolving
case law could justify regulatory measures to protect mental health in the
digital space. By extending the application of the precautionary principle, the
legal precedents set in these cases could pave the way for stronger regulations
aimed at safeguarding online well-being, particularly regarding social media
platforms and their addictive features.
