Chapter 8 - Risk Assessment and Risk Management

Abstract

Traditional risk assessment involves sequential steps of exposure assessment, hazard identification, and hazard characterization, which are merged in risk characterization. Risk management is required if unacceptable risks are identified. Hazard assessment largely relies on data on apical effects, that is, the observable outcome of substance exposure to test animals. While toxicity-testing methods are generally applicable to nanomaterials (with adaptations), their application to comprehensively test all variants of nanomaterials is neither efficient nor compliant with animal welfare statutes. Modern risk assessment approaches integrate data on intrinsic and system-dependent material properties, biophysical interactions, and cellular effects with data on exposure, biokinetics and hazard, referring to animal testing as a last resort. This serves animal welfare requirements and allows for rapid material grouping or categorization regarding risk potential so that (nano)materials of high concern can be targeted for additional scrutiny, while material categories that pose the least risk can receive expedited review.