Therefore, the positive pressure air respirator must be used in the environment where the oxygen concentration is lower than 18.5%. Generally speaking, underground pipelines, mines, cellars and tunnel lights are all anoxic environments. People should first measure the oxygen concentration when entering these environments. Because people's breathing will consume oxygen, even if the oxygen concentration in the local underground space meets the breathing requirements, we suggest using positive pressure air respirator to prevent people from consuming too much oxygen.
3. Using positive pressure air respirator toxic gas to pollute the environment. Gases such as carbon monoxide and hydrogen sulfide are toxic gases, and symptoms of deep poisoning will appear when inhaled slightly. Therefore, in order to ensure their own life safety, when entering the environment with toxic gas, we should use positive pressure air respirator, make good preparations for protection, and use positive pressure air respirator for fire fighting and rescue, hazardous chemical leakage treatment and other scenarios.