Countries continue to advance approaches to support alternatives assessment and substitution of chemicals of concern. Substitution can occur as a response to regulatory activity or in anticipation of regulations or even in non-regulatory scenarios where a company may wish to switch to an alternative substance or technical solution. This document summarises approaches used to support alternatives assessments and substitution by countries and lessons learned. This second edition is based on responses received to a questionnaire as well as discussion from the 2022 OECD Workshop on Government Approaches to Incentivise Substitution. In addition, the document summarises third-party approaches to substitution and economic approaches to incentivise substitution, which are further elaborated in other documents also discussed at the workshop. Links to the topics of innovation and safe and sustainable by design are also drawn.