In December 2020, the Ministry of Ecology and Environment (MEE) of China updated the China IV emission standards for non-road mobile machinery. It set new requirements for particle number (PN) limits, the use of Global Positioning System (GPS) tracking systems, and portable emissions measurement system (PEMS) testing for improved real-world compliance. The new requirements come in the form of amendments to the Chinese law governing diesel engines of non-road mobile machinery (China III, IV). The updated China IV standards will phase in from December 2022 for all diesel non-road equipment with engine sizes smaller than 560kW, for diesel three-wheeler trucks, and for waterway vessels with diesel engines smaller than 37 kW.