Legal analysis: according to the national standard GB/T 18664-2002 "Selection, Use and Maintenance of Respiratory Protective Appliances" for equipping and use, when the operating environment is not oxygen deficient (oxygen concentration ≥18%), the type and concentration of hazardous gases are known, and the concentration of hazardous gases is (1) For the self-absorbing filtering type gas mask: 1) Concentration exceeds the standard <10 times, can choose self-priming filter half mask; 2) Concentration exceeds the standard <100 times, can choose self-priming filter full mask. (2) According to the type of hazardous gases and vapors to choose the applicable filter parts. (3) If protection against hazardous gases and particulate matter is provided at the same time, effective filters or a combination of filters should be selected. (4) For hazardous gases with no or poor warning, give preference to respiratory protection with an expiration indicator or isolated respiratory protection. Legal basis: The Law of the People's Republic of China on Prevention and Control of Occupational Diseases Article 8 The State encourages and supports the research, development, popularization, and application of new technologies, new techniques, new equipment, and new materials conducive to the prevention and control of occupational diseases and the protection of the health of workers, and strengthens the basic research on the mechanism and occurrence of occupational diseases, so as to raise the level of scientific and technological research on prevention and control of occupational diseases; it also actively employs the use of effective The State encourages and supports medical rehabilitation of occupational diseases and the protection of workers' health with new technologies, processes, equipment and materials. The State encourages and supports the construction of medical rehabilitation institutions for occupational diseases. Article 9 The State implements an occupational health supervision system. The administrative departments of health and labor security under the State Council are responsible for the supervision and management of the prevention and control of occupational diseases throughout the country in accordance with the duties determined by this Law and the State Council. The relevant departments of the State Council shall be responsible for the supervision and management of the prevention and control of occupational diseases within their respective areas of responsibility. The administrative departments of health and the administrative departments of labor security of the local people's governments at or above the county level are responsible for the supervision and management of the prevention and control of occupational diseases in their respective administrative areas in accordance with their respective duties. The relevant departments of the local people's governments at or above the county level are responsible for the supervision and management of the prevention and control of occupational diseases within the scope of their respective duties. People's governments above the county level health administrative departments, labor security administrative departments (hereinafter collectively referred to as the supervision and management of occupational health) should strengthen communication, close cooperation, in accordance with their respective division of responsibilities, the exercise of authority and responsibility in accordance with the law.