Toxicity and Safety of Nanomaterials in Food Packaging Applications: A Dimension-Based Review

Nanomaterials are increasingly used in food packaging polymers to enhance barriers, strength, and antimicrobial properties, raising important questions about their migration into food and potential health risks. Driven by these concerns, this review evaluates the toxicity and safety of nanomaterials in food packaging from a dimensional perspective. It explores how dimensionality (0D, 1D, 2D, and 3D) influences nanoparticle transport, gastrointestinal transformation, biological fate, and toxicological responses. Comparing published migration studies, we find that 0D metal and metal oxide nanoparticles tend to migrate more into acidic and aqueous simulants, while 2D nanoclays and graphene-based materials generally release fewer particles but can still emit ionic or fragment species during long-term storage. Correspondingly, IC₅₀ and EC₅₀ values reported across intestinal and hepatic cell models vary significantly among different dimensional classes, indicating that nanomaterials of similar chemistry are not toxicologically identical if they have different dimensions. Although current research offers extensive short-term in vitro and in vivo data, evidence for long-term, low-dose, oral exposure remains very limited. Overall, these findings highlight the need for safety assessments tailored to dimensionality, including realistic migration data, advanced gastrointestinal models, and studies on chronic dietary exposure to support the responsible development of nano-enabled food packaging.