Toxic gases can exist in production raw materials and can be detected by toxic gas detectors. For example, most organic chemicals (VOC) may also be present in by-products of various aspects of the production process, such as ammonia, carbon monoxide, hydrogen sulfide, etc. They are the most hazardous hazards to workers. This hazard includes not only immediate harm, such as physical discomfort, morbidity, death, etc., but also long-term harm to the human body, such as disability, cancer, etc. The detection of these toxic and harmful gases is an issue that our developing countries should start to pay full attention to. TWA (8-hour statistical weighted average), STEL (15-minute short-term exposure level), IDLH (immediate lethal dose) (ppm) and MAC (maximum allowable concentration in the workshop) mg/m3 of common toxic and harmful gases. Depending on the type of gas, its TWA, STEL, IDLH, MAC and other values will be different. Currently, for the detection of specific toxic gases, we use special gas sensors most. It can include the above. All gas sensors listed also include the photoionization detectors introduced in the previous two chapters. Among them, the most common method for detecting inorganic gases, with relatively mature technology and the best comprehensive indicators is the constant potential electrolysis method, which is what we often call electrochemical sensors.

At present, we pay more attention to the detection of gases that can cause acute poisoning, such as hydrogen sulfide, hydrogen cyanide, etc., but not enough attention to the detection of gases that can cause chronic poisoning, such as aromatic hydrocarbons, alcohols, etc. In fact, the latter is very important to workers' health. The safety hazards are no less than those of gases that can cause acute poisoning! They may cause cancer and other invisible diseases, affecting workers' lifespan and health. In addition to the cognitive reasons for the emergence of this phenomenon, the lack of suitable organic gas detectors that can detect lower concentrations on the market is also an important reason. With the development of science and technology and the improvement of people's health awareness, people are no longer satisfied with just "coming to work happily and going home safely", but are pursuing higher quality of life and living conditions. People are not only concerned about today's work, but also about tomorrow - their life after retirement.