What are the vehicle emission standards for annual inspections?

[McCaleb]

Vehicle emission standards are the National IV standard. The following are the harmful substances and hazards of vehicle emissions: Harmful substances in vehicle emissions: Vehicle emissions contain hundreds of different compounds, including pollutants such as solid suspended particles, carbon monoxide, carbon dioxide, hydrocarbons, nitrogen oxides, lead, and sulfur oxides. Hazards of vehicle emissions: While directly harming human health, vehicle emissions also have a profound impact on the environment of human life. Sulfur dioxide in the emissions has a strong irritating odor and, when reaching a certain concentration, can easily lead to "acid rain," causing soil and water sources to acidify and affecting the growth of crops and forests.