Best Available Techniques (BAT) have emerged as a key policy tool to prevent and control the emission of industrial pollutants, and thus to ensure the protection of human health and the environment. This report presents the first comprehensive analysis of approaches to establishing BAT and similar concepts around the world, including in OECD members (Korea, the United States, the European Union and New Zealand) and partners (the Russian Federation, India and the People’s Republic of China and) as well as under international conventions. The report demonstrates the key characteristics of more than nine methodologies to establish BAT and similar concepts, providing governments with good practice insights on how to effectively design or review their approach to determining BAT. It also presents a unique, international compilation of existing BAT documents, allowing interested stakeholders to seek guidance from already identified BAT. This is the second in a series of reports developed as part of the OECD’s BAT project.