What does Euro IV emission standard mean?

[Albuquerque]

Euro IV standard refers to the Euro IV emission standard, which was implemented at the end of 2005 and is an important standard for vehicle exhaust emissions, currently enforced in most countries. Composition of vehicle emission pollutants: Vehicle emission pollutants mainly include HC (hydrocarbons), NOx (nitrogen oxides), CO (carbon monoxide), PM (particulate matter), etc. These are primarily emitted through the vehicle's exhaust pipe. Approximately 45% of HC and a very small amount of other pollutants are emitted from the crankcase and fuel system. Hazards of pollutants: Among the aforementioned vehicle emission pollutants, CO is a product of incomplete fuel combustion and poses significant harm to human health. HC mainly results from fuel evaporation and incomplete combustion, consisting of over 200 different components, including carcinogenic substances. NOx is formed by the combination of nitrogen and oxygen under high temperature and pressure conditions in the combustion chamber. After being emitted into the atmosphere, it turns into NO2 (nitrogen dioxide), which is highly toxic and has adverse effects on both humans and plant growth. It is one of the main substances responsible for acid rain and photochemical smog.