专家回应网传“高铁二氧化碳超标”：未超标准限值2500ppm

Core Viewpoint - The reported CO2 concentration levels in high-speed train carriages do not exceed safety standards set by relevant regulations, and the standards for rail vehicles differ from those for buildings [1][2]. Group 1: CO2 Concentration Standards - The CO2 concentration control standard for passenger trains in China is set at a maximum of 2500 ppm according to TB/T 3493-2017, while European standards allow up to 5000 ppm [1]. - The reported values circulating online reference the GB 50736-2012 standard for civil buildings, which is not applicable to passenger trains [1]. Group 2: Air Quality Management in Trains - High-speed trains are designed with a fully sealed body, and air exchange is managed entirely by the air conditioning system, providing a fresh air volume of over 15 m³/h per person, with air exchange rates of 6 to 12 times per hour [1]. - During operation in non-tunnel sections, CO2 levels typically remain below 1500 ppm; however, when passing through tunnels, pressure protection measures may temporarily increase CO2 levels without impacting passenger health [2].