The following toxic gases are the ones most commonly encountered:

  Carbon monoxide: This kind of gas is mainly produced in the process of mine fire and gas and coal dust explosion. It is colorless, odorless and odorless. It is lighter than ordinary air. It mostly exists in the middle and upper part of the roadway. It is a very toxic gas. When the concentration of air reaches 0.4%, people will lose consciousness in a short time and die soon.
After death from poisoning, the face and lips are pink, and there are small red spots under the thighs and armpits.
  Nitrogen dioxide: This gas mainly comes from downhole firing. Pure nitric oxide is a red-brown gas. The underground nitric oxide has been diluted by the air flow, so it is generally grey-white. It has a strong irritating smell, heavier than the general air, and mostly exists in the middle and lower part of the roadway. It is a highly toxic gas, which has a strong corrosive effect on human eyes, respiratory tract and lung tissue, and can be induced. Pulmonary edema, cor pulmonale, etc. When the concentration of nitrogen dioxide in the air reaches 0.025%, people can die in a short time. Special attention should be paid here to the fact that such gas poisoning is often delayed and often occurs 4-6 hours after the well is lifted. Attention must be paid to it.
  Sulphur dioxide: It is mainly produced by coal oxidation and spontaneous combustion of coal containing sulphur, as well as by blasting in sulphur-bearing coal seam. This gas is colorless, has a strong sulfur odor, heavier than ordinary air, and mostly exists in the middle and lower part of the roadway. Sulfur dioxide has a strong stimulating effect on human eyes and respiratory system. When its concentration in the air reaches 0.05%, it will cause bronchitis, emphysema, and serious death in a short time.
  Hydrogen sulfide: Hydrogen sulfide gas often exists in coal seam, which is released naturally in the process of coal falling. Some substances decay and sulfur-containing minerals can also decompose into hydrogen sulfide when they meet water. This kind of gas is colorless, slightly sweet and smells of rotten eggs. It is heavier than ordinary air. It mostly exists in the middle and lower part of the roadway. It is a kind of gas with strong toxicity. It can stimulate the mucosa of human eyes, nose and throat. When the concentration of air reaches 0.1%, people will die in a short time.
  Through the use of toxic and harmful gas detector, staff can be prompted to take safety measures or start relevant automatic control devices, so as to ensure safe production in factories and avoid major accidents. If you are interested, pls contact us: Email: info@china-oceanus.com; Tel: +86-371-60998169