The concept of "essential uses" (EU) has been proposed as part of the discussions surrounding the regulatory framework for per- and polyfluoroalkyl substances (also known as PFAS or "forever chemicals"). Its aim is to question the justification for the use of hazardous chemicals in order to restrict their use more quickly and radically. In its report, Ineris examines the foundations and application of the EU concept in chemical risk management, with a specific focus on PFAS substances. It analyses the available scientific and methodological work related to the EU concept and similar approaches, and reviews the steps proposed by the European Commission for its implementation. The report specifically explores the links between the EU concept, alternatives assessment, and socio-economic considerations in applying the essentiality criteria. An illustrative application of the concept to PFAS uses is also provided. The report highlights the need for shared definitions and stakeholder consultations. It suggests that applying the EU concept would not significantly alter the current review of PFAS restrictions. In conclusion, the EU concept could help prioritise chemical risk management measures and enhance their transparency. The report makes recommendations to support its potential implementation.