Why is the national standard in China generally lower than that in Europe and America?

Because China's quality level from testing technology to industry finishing can't meet the standard compared with foreign countries, so we can only lower the standard, which is the gap. For example, the smog index, around 300 in the Imperial Capital, is actually very high abroad, just to appease people's hearts. Standards are set by people, purely for checks and balances, not to completely eliminate unqualified and unsafe. If a country's general standards are low, its evaluation and testing institutions will not set relevant high standards.