(d) In the European Union emissions of nitrogen oxides (NOx),total hydrocarbon (THC), nonmethane hydrocarbons (NMHC),carbon monoxide (CO) and particulate matter (PM) are regulated for most vehicle types,including cars, trucks (lorries),locomotives, tractors and similar machinery, barges, but excluding seagoing ships and aeroplanes. Emission standards set quantitative limits on the permissible amount of specific air pollutants that may be released from specific sources over specific time frames.