Last month, our team joined a pivotal webinar hosted by the European Food Safety Authority (EFSA), here regulatory scientists, academic experts, and industry stakeholders gathered to shape the future of nanomaterial guidance in Europe. Among the many technical and strategic discussions held, one issue stood out for its ambiguity and far-reaching implications: the treatment of organic nanoparticles in regulatory risk assessments. Are they to be considered alongside inorganic nanomaterials, or do they warrant their own regulatory pathway, as they naturally occur in food, water and environment?
EFSA’s existing guidance, as it stands, is built primarily around engineered inorganic nanoparticles—materials like titanium dioxide and silica, which exhibit high persistence, distinct surface properties, and potential to cross biological barriers. These materials have been subject to detailed scrutiny through defined toxicological endpoints and rigorous characterisation protocols.
However, as organic nanoparticles—such as lipid-based carriers, nano-encapsulated plant compounds, or polymeric particles—become more common in food, feed, and pharmaceutical applications, a regulatory blind spot emerges since their properties differ fundamentally from their inorganic counterparts. They often dissolve more readily, degrade into innocuous byproducts, and may present fewer long-term accumulation risks. Yet, this complexity makes them harder to detect, quantify, and classify within traditional frameworks.
The EFSA workshop emphasized a significant step forward in embracing a unified and scientifically innovative guidance strategy. Several key developments are especially relevant to the case of organic nanoparticles. EFSA is merging its two nanomaterial guidance documents into a comprehensive framework, recognising that many nano-enabled substances sit at the interface of multiple definitions. The Agency reaffirmed its use of Counting Rule #4, under which every identifiable particle—even those embedded in aggregates or agglomerates—is counted. This approach, while conservative, complicates matters for organic materials that may degrade before reaching systemic circulation. In fact, organic nanoparticles may not persist in systemic tissues, especially if they dissolve or are metabolised en route. However, the lack of validated tools makes it difficult to determine this reliably, raising both scientific and regulatory uncertainty.
Dissolution behaviour emerged as a critical discriminator in the need for nano-specific assessment. EFSA is planning to refine criteria to classify materials into categories based on full, partial, or negligible solubility—directly relevant for many organic nanomaterials. Furthermore, current tools such as electron microscopy and ICP-MS are not efficient for characterising organic nanoparticles. Experimental methods like hyperspectral Raman imaging or HPLC-MS are promising but not yet validated or widely accessible.
So, where does this leave regulators—and applicants? Should organic nanoparticles be regulated identically to inorganic ones, using the same standardized metrics and default assumptions or might there be justification for a different approach if they degrade rapidly and pose minimal systemic risk?
There is no clear consensus yet, but EFSA appears to be leaning toward a tiered, evidence-based approach. This would permit differential treatment only when applicants can convincingly demonstrate rapid dissolution, lack of systemic exposure, and low potential for bioaccumulation—ideally through validated methods and reproducible results.
Importantly, EFSA’s upcoming guidance, expected for public consultation by the end of 2025, will likely include decision trees for classifying borderline materials, requirements for validated solubility tests in physiological media, case studies of organic nanomaterials with successful risk assessment pathways, and clarified rules for excluding nano-specific evaluation based on demonstrated degradation.
The EFSA webinar underscored the growing need to strike a balance between precaution and practicality. Organic nanoparticles are not inherently safe, but they are also not equivalent to persistent inorganic nanoscale materials. An overly cautious approach may stifle innovation and impose burdensome testing, while a lax one could miss genuine risks.
At Innovamol, we believe that the future of organic nanomaterial regulation lies in flexibility grounded in science. With the integration of New Approach Methodologies (NAMs), AI-based modelling and harmonised guidance across agencies like ECHA, EMA and US FDA, the regulatory path is becoming clearer—though challenges remain.
Organic nanoparticles are here to stay. Whether in functional foods, veterinary applications, or novel drug delivery systems, their role is expanding—and so must our understanding of their risks and behaviours. As EFSA refines its approach to nanomaterials, the distinction between “organic” and “inorganic” may blur, but the need for smart, adaptable regulation has never been sharper.
“Not everything that counts can be counted, and not everything that can be counted counts” – William Bruce Cameron