Traceability in nanotechnology faces several challenges: 1. Complexity: The small size and high variability of nanomaterials make tracking difficult. 2. Cost: Implementing sophisticated tracking systems can be expensive. 3. Regulatory Variability: Different countries have different regulations, complicating global traceability. 4. Data Management: Maintaining and updating large volumes of data is resource-intensive. 5. Technology Integration: Integrating new traceability technologies with existing systems can be challenging.