ISO 8573-1 Class 0: The Gold Standard for PurityISO 8573-1 Class 0：纯度的黄金标准 What exactly is Class 0? According to the ISO 8573-1 standard, air quality is categorized by the amount of contaminants allowed per cubic meter. Class 1 permits a tiny amount of oil (0.01 mg/m³), but Class 0 is more stringent. It is the […]