What are the automotive emission standards?
1 Answers
China's automotive emission standards include National I, National II, National III, National IV, and National V emission standards. Currently, the domestic automotive exhaust emission standard in China is National V. The National VI standard will be officially implemented nationwide in July 2020, with some regions having already implemented the National VI standard ahead of schedule in July 2019. Here is more related information: 1. Automotive emission standards: Automotive emission standards refer to regulations on the content of harmful gases emitted from vehicle exhaust, such as CO (carbon monoxide), HC+NOx (hydrocarbons and nitrogen oxides), and PM (particulate matter, soot). Vehicle exhaust contains 150-200 different compounds. Since vehicle exhaust emissions primarily occur between 0.3 meters and 2 meters, which coincides with the human breathing range, they pose severe health hazards. The most harmful substances to humans include carbon monoxide, hydrocarbons, nitrogen oxides, and solid particulate matter. 2. Hazards of carbon monoxide: Carbon monoxide binds to hemoglobin in the blood 250 times faster than oxygen. Carbon monoxide enters the bloodstream through the respiratory system and combines with hemoglobin to form carboxyhemoglobin, thereby impairing the blood's ability to transport oxygen to various tissues, harming the central nervous system, and causing functional disorders in sensation, reaction, comprehension, memory, etc. In severe cases, it can endanger the circulatory system, posing life-threatening risks. Nitrogen oxides mainly refer to nitric oxide and nitrogen dioxide, both of which are harmful gases to humans, particularly to the respiratory system. Exposure to air with a nitrogen dioxide concentration of 9.4 mg/m³ for 10 minutes can cause respiratory dysfunction.
