On the 1st August, 2025, the Court of Justice of the European Union (CJEU) delivered its definitive verdict: it upheld the annulment of the 2020 classification that had designated certain powdered forms of titanium dioxide (TiO₂) as a Category 2 carcinogen when inhaled.
This judgment marks a pivotal moment – not only for the titanium dioxide industry but also for the broader arena of chemical regulation and judicial oversight.
For industry stakeholders, the ruling is a win. Manufacturers will no longer have to adhere to the “Suspected of causing cancer by inhalation” labelling and safety data sheet requirements for TiO₂ in powdered form. As one industry advocate put it, the ruling is nothing short of a “miracle,” preventing a potential “tsunami effect” across raw material sectors.
Manufacturers of both liquid and solid mixtures containing sufficient fine-particle TiO₂ were also required to label products with supplemental hazard statements:
- EUH211: “Warning! Hazardous respirable droplets may be formed when sprayed. Do not breathe spray or mist.” (for liquids)
- EUH212: “Warning! Hazardous respirable dust may be formed when used. Do not breathe dust.”
The Heart of the Judgment: Intrinsic vs. Contextual Risk
This ruling reflects a critical principle: regulatory classification must be rooted in intrinsic hazard, not context-limited, conditional outcomes.
The General Court determined that carcinogenic classification based on particle form, size, and concentration – not purely on chemical identity – amounted to an extrinsic risk, not an intrinsic property of TiO₂.
TiO₂ itself isn’t universally carcinogenic. It only poses a cancer risk in powdered form, with specific fine-particle content, and under conditions such as “lung overload” (the cancer effect was observed in rats, under chronic inhalation exposure at high concentrations leading to lung overload – where the lungs’ natural clearing mechanisms are overwhelmed. No conclusive evidence showed the same risk in humans at real-world exposure levels).
Can inhaled particles that only become harmful under defined exposure thresholds still be deemed intrinsically dangerous? The General Court said no.
By invalidating this classification, the court reaffirmed the necessity of relying on robust scientific evidence, accurate exposure scenarios, and tested thresholds, not on speculative or worst-case constructs.
Advocate General vs. Final Ruling
Advocate General Ćapeta, in her February 2025 opinion, took a broad view: EU courts should limit their review to procedural missteps -not second-guess scientific assessments. She argued that “courts are not scientists” and cautioned against overstepping into regulatory territory. Moreover, she suggested the concept of intrinsic properties should accommodate physical forms, arguing that dismissing context-linked hazards undermines regulatory efficacy.
Yet, the CJEU pushed back. It affirmed that agencies like the Committee for Risk Assessment must demonstrate they genuinely assessed all relevant factors, especially when decisions affect industry and public health alike.
Scientific Rigour Over Regulatory Caution
Make no mistake – science demands rigour. Labelling powders with Carc. 2, H351 (inhalation), and affixing EUH statements, was a precautionary move, but it risked overstating the hazard.
In regulatory realms, especially within the chemical sector, nuance matters: not all inert substances in powdered form should be equated with inherent carcinogens.
This ruling doesn’t dismiss the utility of safety measures. It merely insists these measures, be they testing protocols, exposure limits, or labelling rules, must be anchored in clear, reproducible science:
- Particle-size analysis, to establish whether TiO₂ contains ≥ 1% particles ≤ 10 μm;
- Dosage-response modelling, illustrating actual risk at realistic exposure levels;
- Occupational safety frameworks, ensuring that even if a hazard exists under extreme exposure, it can be managed effectively (e.g., ventilation, PPE).
A Win for Evidence-Based Oversight
This case was about ensuring that regulatory actions are based on sound science rather than assumption. The hazard classification for titanium dioxide required specific, technical conditions, namely, the presence of at least 1% of fine particles, triggering the label Carc. 2, H351 (inhalation), along with EUH211 or EUH212 where applicable. By overturning that classification, the court reaffirmed the principle that hazard identification must rely on a substance’s intrinsic properties and be backed by rigorous, transparent testing.
This decision upholds the integrity of chemical regulation – not by weakening oversight, but by demanding that it be grounded in credible scientific evidence, not precautionary labelling driven by uncertainty.
