The essential-use concept is a tool that can guide the phase-out of per- and polyfluoroalkyl substances (PFAS) and potentially other substances of concern. This concept is a novel approach to chemicals management that determines whether using substances of concern, such as PFAS, is truly essential for a given functionality. To assess the essentiality of a particular use case, three considerations need to be addressed: (1) the function (chemical, end use and service) that the chemical provides in the use case, (2) whether the function is necessary for health and safety and critical for the functioning of society and (3) if the function is necessary, whether there are viable alternatives for the chemical for this particular use. A few illustrative examples of the three-step process are provided for use cases of PFAS. The essential-use concept takes chemicals management away from a substance-by-substance approach to a group approach. For PFAS and other substances of concern, it offers a more rapid pathway toward effective management or phase-out. Parts of the concept of essential use have already been widely applied in global treaties and international regulations and it has also been recently used by product manufacturers and retailers to phase out substances of concern from supply chains. Herein some of the common questions and misinterpretations regarding the practical application of the essential-use concept are reviewed, and answers and further clarifications are provided.

中文翻译：

---

寻找可行的必要性：关于“必要用途”概念的常见问题和误解

必要用途概念是一种工具，可以指导逐步淘汰全氟和多氟烷基物质 (PFAS) 以及其他可能引起关注的物质。这个概念是一种化学品管理的新方法，它确定使用关注物质（如 PFAS）对于给定的功能是否真正必不可少。为了评估特定用例的重要性，需要考虑三个因素：(1) 化学品在用例中提供的功能（化学品、最终用途和服务），(2) 该功能是否对健康和安全和社会运作的关键，以及 (3) 如果该功能是必要的，是否有针对该特定用途的化学品的可行替代品。为 PFAS 的用例提供了三步过程的一些说明性示例。必要用途概念将化学品管理从逐个物质方法转变为群体方法。对于 PFAS 和其他受关注物质，它提供了一条更快速有效管理或逐步淘汰的途径。部分必要用途概念已广泛应用于全球条约和国际法规中，最近也被产品制造商和零售商用于逐步淘汰供应链中的关注物质。此处回顾了有关必要用途概念实际应用的一些常见问题和误解，并提供了答案和进一步说明。它为实现有效管理或逐步淘汰提供了更快速的途径。部分必要用途概念已广泛应用于全球条约和国际法规中，最近也被产品制造商和零售商用于逐步淘汰供应链中的关注物质。此处回顾了有关必要用途概念实际应用的一些常见问题和误解，并提供了答案和进一步说明。它为实现有效管理或逐步淘汰提供了更快速的途径。部分必要用途概念已广泛应用于全球条约和国际法规中，最近产品制造商和零售商也使用它来逐步淘汰供应链中的关注物质。此处回顾了有关必要用途概念实际应用的一些常见问题和误解，并提供了答案和进一步说明。