While developed countries have reduced fuel sulphur levels to 10 parts per million (ppm), in developing and transitional countries the average sulphur levels (particularly in diesel fuels) are high and may even reach 10,000 ppm. PCFV efforts to lower sulphur levels in fuels, by improving refinery technology and/or fuel import standards have resulted in major progress in Africa, Latin America, Asia and Eastern Europe. 

Low sulphur fuels are critical to lowering direct emissions of particulate matter from on-road traffic (that are of great concern due to their health impacts) and black carbon emissions (an important climate pollutant).