The goal of this report is to characterise the current landscape of third-party (not government or regulated industry) approaches to chemical substitution across OECD countries, and in doing so, to provide information on those approaches that can be used by governments and other stakeholders to inform their chemical risk management efforts. This work responds to an ever-increasing focus on informed substitution and alternatives assessment brought about by government policies, market and supply chain factors, and consumer and worker concerns. Collectively, these approaches cover many different aspects of managing and reducing chemical risk and are targeted toward a variety of audiences—from providing tools and frameworks that help practitioners conduct alternatives assessments, to implementing training and technical assistance for practitioners as well as communities and small businesses, building the capacity of the field through professional networks, stimulating market demand for retailers and manufacturers to provide safer chemistries, and helping consumers make informed purchasing decisions.