PPE

Understand the fire smoke and pay attention to the safety of firefighters

Firefighters spend most of their working time dealing with “fog and smoke”. Of course, they are not like immortals who can “fly through the clouds”, on the contrary, they have to suffer from the harm and torture of smoke. More than 85% of the fire deaths are caused by toxic smoke. As we all know, the main hazard of fire smoke is carbon monoxide (CO), but hydrogen cyanide (HCN) is also the invisible killer of combustion products. Experiments have shown that high concentration of HCN can immediately lead to poisoning of firefighters without wearing air breathing apparatus, and even low concentration of HCN can cause fatal heart disease and other symptoms after long-term inhalation. Moreover, studies have shown that there is a synergistic effect between the toxic effects of HCN and CO in fire smoke, That is to say, if these two gases act at the same time, it will aggravate the toxic reaction of firefighters

Where does HCN come from

in the past 50 years, the application of plastic products in buildings and internal structures has grown rapidly, and the combustion forms and products of fire have also changed greatly. No one will forget the fire that shocked the whole country in a teacher’s apartment on Jiaozhou Road in Shanghai on November 15, 2010, which eventually killed 53 people and injured more than 70 people. After the accident, Luo Lin, director general of the State Administration of work safety, said that a large number of flammable materials such as polyurethane foam were used illegally at the scene of the accident, which was the main reason for the rapid spread of fire. Zhu Liping, deputy director of the Fire Department of the Ministry of public security, also stressed in the interview that a large number of polyurethane foam insulation materials on the facade of the building, burning fast and producing a large number of highly toxic hydrogen cyanide gases, are the main causes leading to the death of many people. Br / >
HCN may occur in any fire, whether it is a building fire, a vehicle fire or a forest fire. HCN is produced by incomplete combustion of nitrogenous materials when the temperature exceeds 315 ℃ ° HCN will be released in the form of gas and then inhaled by the victim. 1t was found that 130ug / g HCN was produced after burning cotton, 1100 UG / g HCN was produced after burning paper, and 6300 UG / g HCN was produced after burning wool fabric. 1t is worth noting that although the fire has been put out, the concentration of HCN gas is still very high< The harm of HCN and CO gas can be divided into three types: irritant, asphyxiating and toxic substances, which exist in the form of gas or solid. Although there are many chemical substances in fire smoke, asphyxiating and toxic substances are often concerned because of their potential harm to the health of firefighters the CO gas in fire smoke can affect the oxygen carrying capacity of human blood circulation system, and the toxicity of HCN gas is 35 times greater than that of CO gas. Once exposed or inhaled, it can affect the internal tissues of human organs, including serious damage to the heart and brain, and can cause cognitive decline or drowsiness in a short time, Reduce the escape ability of victims and the rescue ability of firefighters. When HCN is combined with CO, its toxic effect will be enhanced, and the situation will be worse than when it exists alone. The harm of gases with different concentrations to human body can be shown in the following table copyright notice: This article is reproduced by 1nternet media, only representing 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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