A Pollutant Release and Transfer Register (PRTR) is a publicly accessible database or inventory of chemicals or pollutants released to air, water and soil and transferred off-site for treatment. It brings together information about which chemicals are being released, where, how much and by whom. The OECD supports countries in establishing and implementing a Pollutant Release and Transfer Register to develop, disseminate and harmonise information, methodologies and tools. The OECD also assists countries in establishing and implementing Best Available Techniques based policies to achieve integrated pollution prevention and control, by providing knowledge, and best practices amongst countries and different stakeholders.