PPE

Hazard characteristics of working in confined space

The working environment is complex

the confined space is narrow and the ventilation is not smooth, which is not conducive to the gas diffusion

1. The production, storage and use of hazardous chemicals or biochemical reaction (protein corruption), respiration, etc., produce toxic and harmful gases, which are easy to accumulate, and form a high concentration of toxic and harmful gases after a period of time< Some poisonous and harmful gases are tasteless, which can easily make operators relax their vigilance and lead to poisoning and suffocation accidents. 1n addition, the leakage or sudden influx of undercurrent around some confined working spaces, the collapse of buildings or the flow of other mobile solids (such as mud and sand) and the leakage of electric appliances are also the main reasons for the operation, The machinery used in the operation will bring potential hazards to the operators in the confined space 3. When the concentration of some toxic gases is high, they can paralyze the nerves (such as hydrogen sulfide), but can not be smelled the poor lighting and communication in confined space bring difficulties to normal operation and emergency rescue in addition, the infiltration or sudden influx of undercurrent around some confined working space, the collapse of buildings or the flow of other mobile solids (such as mud and sand), the leakage of electrical appliances and the use of machinery in operation, 1t will bring potential danger to operators in confined space it is very dangerous. Once an accident occurs, it often causes serious consequences. poisoning and suffocation of operators occur in an instant. Some toxic gases can cause death in minutes or even seconds after poisoning hydrogen sulfide (H2S) is a colorless gas, which has a special odor (rotten egg odor) and is easily soluble in water; The proportion is larger than that of air, and it is easy to accumulate in the low-lying places such as poorly ventilated urban sewage pipes, inspection wells, septic tanks, sewage tanks, pulp tanks and other kinds of fermentation tanks and vegetable pickling tanks (nitrogen compounds such as protein decomposition). Hydrogen sulfide is a kind of asphyxiating gas and a strong neurotoxin. When the concentration of hydrogen sulfide is 0.4mg/m3, people can obviously smell the odor of hydrogen sulfide; The higher the concentration is, the faster the olfactory fatigue is, and the more easily people lose their vigilance; Over 760mg / m3, pulmonary edema, bronchitis and pneumonia can occur in a short time, which may cause life-threatening; Over 1000 mg / m3, it can cause electric shock like death carbon monoxide (CO) is a colorless and odorless gas, which is slightly soluble in water, ethanol, benzene and other organic solvents; 1t belongs to flammable, explosive and toxic gas, which can form explosive mixture when mixed with air, and can cause combustion and explosion when meeting open fire and high heat. Carbon monoxide in the blood is easy to combine with hemoglobin (relative to oxygen) and cause tissue hypoxia. Mild poisoning patients had headache, dizziness, tinnitus, palpitation, nausea, vomiting and weakness, and the blood carboxyhemoglobin concentration could be higher than 10%; 1n addition to the above symptoms, the skin and mucous membrane of moderate poisoning patients were cherry red, fast pulse, irritability, unsteady gait, light to moderate coma, and the blood carboxyhemoglobin concentration could be higher than 30%; Severe patients with deep coma, pupil narrowing, muscle tension enhancement, frequent convulsions, incontinence, shock, pulmonary edema, severe myocardial damage, etc asphyxia: the process of causing hypoxia in human tissues is called asphyxia. The effects of different concentrations of oxygen on human body are as follows: it is easy to increase casualties due to blind rescue a well-known multinational chemical company once made statistics that 50% of the dead in confined space accidents are rescue workers, and the casualties increase due to improper rescue due to poor safety awareness and lack of safety knowledge, some confined space operation units and operators have not formulated a safe operation system, or the system is imperfect and not strictly implemented, the safety measures and monitoring measures are not in place and not implemented, the hazard identification is not done before the implementation of confined space operation, and the targeted emergency response plan is not formulated, Due to the lack of necessary safety facilities and emergency rescue equipment, or the lack of training and drills despite the emergency plan, the operators and guardians lack basic emergency knowledge and self rescue and mutual rescue ability, the scientific and effective rescue can not be carried out under the accident state, and the casualties are further expanded this article is a reprint of 1nternet media, which only represents the author’s point of view and has nothing to do with this website. 1f the information column articles and comments violate your legal rights, please call to let us know and we will deal with them in time

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