The Working Party on Pollution and Energy (GRPE) prepares regulatory proposals concerning motor-vehicle pollutant emissions, fuel efficiency, energy consumption, and similar environmental performance areas for consideration by the World Forum/WP.29. More than 120 government, industry, and other interested experts contribute to this work at each session.

GRPE work is closely related to European Union emissions and fuel-efficiency standards. UN Regulation Nos. 49, 83, and 101 correspond respectively to the EU emissions standards for light passenger vehicles (e.g., Euro 6), heavy vehicle emissions standards (e.g., EURO VI), and fuel-efficiency and CO2 emissions standards for light passenger vehicles.

GRPE usually convenes during January and June of each year and supervises a number of subgroups working on specific technical aspects of vehicle powertrain environmental performance.