What are the hazards of human and animal inhalation of sulfur hexafluoride gas?- SF6在线监测系统_SF6检漏仪_SF6传感器_SF6密度继电器

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What are the hazards of human and animal inhalation of sulfur hexafluoride gas?

发布时间：2019-02-17 来源：ydlcb 浏览次数：41次

From a medical point of view, the degree of impact of various decomposition gases and products on the human body not only depends on the size of its toxicity, but also the size of the amount inhaled into the human body and the physical quality of each person. As an objective basis for judgment, Japan sets the allowable concentration of each animal substance to level 5. I.e. A - minimum lethal concentration; B - semi-lethal concentration (50% is the death concentration); C -- Short time residence limit, usually 15min; D - the lowest concentration at which toxic reactions occur; E -- for 8h a day, 40h a week of normal working time, most people work at this concentration, will not have adverse effects on health. As early as 1979, Shanghai First Medical College and the Institute of Occupational Disease Prevention and Control of Shanghai Chemical Industry Bureau conducted an investigation and animal tests on people engaged in or exposed to SF6 gas for a long time. In the occupational epidemiological survey of the workers of the two enterprises that produce and use SF6 gas, the workers who are similar in age, sex, labor intensity, professional service, smoking or not were grouped and compared, and no obvious harm was found to the health of the workers. However, from the point of view of the statistical incidence of symptoms, the number of people showing weakness, poor memory, sore throat, chest tightness is more.

In the group acute static exposure test and subacute static exposure test on animals (female rats and mice), the mice were placed in different concentrations of SF6 new gas or (in contact with the arc) in the gas group box. As a result, the acute static exposure test showed no abnormalities, while the subacute static exposure test showed mild submicroscopic structural changes in the pulmonary capillaries of one rat under electron microscopy. Whether it is caused by SF6 gas is difficult to determine due to the limited number of animals tested.

Sulfurized gases are non-toxic, but are heavier than gases found so far, about five times the density of air. So once this gas leaks, it is easier to deposit at the bottom of the space. When the concentration is high, it is easy to shine into the human body and cause harm. It will cause oxygen discharge in the low zone. People are often active in the indoor low area, and even when they enter the cable trench and cable shaft, suffocation or even death will occur in serious cases. Therefore, monitoring the sulfur hexafluoride content and oxygen content in the environment is the key to ensure the safety of people working in the environment.

On the other hand, about 90% of sulfur hexafluoride gas is used for insulation and arc extinguishing of power industry equipment. Once the sulfur hexafluoride in this case is leaked, the arc generated during the cutting process of the equipment after operation will lead to the generation of many fluorides and sulfides in the chamber of the closed high-voltage power equipment. Most of these fluorides and sulfides are toxic or even highly toxic, although the arc will be quickly synthesized and reduced back to the original gas, but there is still a considerable proportion of chemical mixture of toxic gases produced. Occasionally, such as engineering installation contact with the mixture of gases after these leaks, no effect on the human body. However, long-term contact with staff such as power maintenance, inspection, etc., must pay attention to entering the room equipped with sulfur hexafluoride electrical equipment should be ventilated in advance or install sulfur hexafluoride leakage online monitoring alarm system to ensure personnel safety.

Toxicological data of sulfur hexafluoride

1. Acute toxicity: rabbit intravenous injection LD50:5790mg /kg.

2, sulfur hexafluoride is a choking agent, in high concentrations will be breathing difficulties, wheezing, skin and mucosa blue, systemic convulsion. After inhaling a mixture of 80% sulfur hexafluoride and 20% oxygen for a few minutes, the human body will experience numbness in the limbs and even suffocation. China stipulates that the allowable concentration of sulfur hexafluoride gas in the air in the operation room should not be greater than 6g/m3 or the oxygen content in the air should be greater than 18%; For short-term exposure, the allowable concentration of sulfur hexafluoride gas in the air is not greater than 7.5g/m3. Sulfur hexafluoride is an inert gas with low toxicity but asphyxiating effect on human body. In the course of life or use, some trace amounts of toxic sulfur of low fluorine compounds and fluorine oxides will be broken down.

3. Acute toxicity LD50:5790mg /kg (rabbit vein).

Usually inhaled sulfur hexafluoride is non-toxic, but to prevent hypoxia. When the concentration of sulfur hexafluoride in the environment is too large, it is easy to cause hypoxia and asphyxia. If people ingest a certain amount of sulfur hexafluoride gas, they will feel dizzy and wheezy, and their voice will become dull and hoarse. They should go outdoors to breathe fresh air in time.

Sulfur hexafluoride gas is often used as arc insulation in power plant equipment. When sulfur hexafluoride leaks, it will cause insufficient oxygen in the room, which may lead to death from hypoxia. Therefore, sulfur hexafluoride online monitoring system will be adopted in power plants to timely alarm the amount of sulfur hexafluoride leakage.

The common environment exposed to sulfur hexafluoride is the following, the sulfur hexafluoride switch room of power transformation and distribution, the sulfur hexafluoride gas storage warehouse, the sulfur hexafluoride manufacturer, the laboratory of the high voltage switch factory, the laboratory of the Chinese Institute of Electrical Science and Technology, and the sulfur hexafluoride transport link.

If it can be confirmed that the sulfur hexafluoride in the contact environment is caused by the leakage of pure sulfur hexafluoride gas, the leakage amount is not excessive, and when the ventilation can be scheduled, it will not cause serious harm to people. If the leakage is mixed gas, such as the switch room and the recovered sulfur hexafluoride gas storage room, once the leakage of sulfur hexafluoride gas mixture is easy to cause suffocation, excessive inhalation of sulfur hexafluoride will lead to chest tightness, and excessive inhalation of sulfur hexafluoride in a short time will also lead to respiratory tract damage and bleeding, nasal dryness and bleeding. Long-term exposure and trace inhalation of sulfur hexafluoride can easily lead to skin tumors, respiratory tract damage, oral ulcers, and serious corneal inflammation.

Sulfur hexafluoride is non-flammable. Inhalation of sulfur hexafluoride should be quickly removed from the site to fresh air. Keep your airway clear. Administer oxygen if breathing is difficult. If breathing stops, give artificial respiration and seek medical attention immediately.