Leachables are chemical entities that migrate spontaneously from the final container closure system, packaging components and/or processing equipment under recommended conditions of product use and storage. Unlike leachables, extractables are generated under exaggerated temperature and time conditions in the presence of an appropriate solvent. Increasing evidence suggests that leachables may pose a safety risk by causing toxicity, carcinogenicity, immunogenicity and/or endocrine dysregulation. These substances may also alter product physico-chemical properties via interaction with the active pharmaceutical ingredient or the excipients in product vehicle, thereby adversely affecting the final product quality. The evaluation of leachable compounds begins with a thorough identification of extractable compounds released from the production and packaging components under exaggerated conditions. The set of observed extractables helps to identify possible targets to be monitored in a subsequent leachables study over extended time periods. Although extractables and leachables also present a challenge for the safe use of device components (e.g., metered dose inhalers, dry powder inhalers, nasal spray devices or various implants), this review focusses on a safety risk assessment for specified therapeutic biological protein products. Regulatory, safety and scientific considerations in evaluating extractables and leachables are discussed, along with strategies for the analytical identification, quantification and monitoring.