Best Available Techniques (BAT)
The Industrial Emission Directive (IED) and the best Available Techniques

"Best available techniques": the most effective and advanced stage in the development of activities and their methods of operation, demonstrating the practical suitability of particular techniques to form, in principle, the basis of ELVs and other permit conditions aimed at avoiding and, where this proves impossible, generally reducing emissions and impact on the environment as a whole;

"Best": the most effective techniques for achieving a high general level of protection for the environment...