Differences: different concerns, ISO9000 is a quality management system, focusing on whether the product quality of enterprises meets the product quality standards and the stability of product quality; ф140000 is an environmental management system, with environmental protection as the core, which is the commitment of enterprises to minimize the environmental impact in the process of production and operation. OHSAS is an occupational health and safety management system, which pays attention to the occupational health and safety of enterprise employees, and aims to protect the occupational health and safety of enterprise employees as much as possible in the process of production and operation.