hydrogen cyanide – lightning killer! look out!

Hydrogen cyanide, as a kind of asphyxiating gas, is known as “lightning killer”. 1t is widely used in organic chemistry, electroplating, mining, metallurgy, paint, dye, rubber and other industries. Cyanide is mostly synthetic, but a small amount exists in natural substances, such as bitter almond, loquat kernel, peach kernel, cassava and ginkgo. Among them, electroplating, paint, dyestuff, rubber and other industries have more contact opportunities< 1n 2004, a hydrogen cyanide gas leakage accident occurred in a chemical plant in Shandong Province, and 22 people were poisoned in 2005, the villagers of Xiaguan village, guanpo Town, Zhao’an County, Fujian Province caused a group poisoning accident of hydrogen cyanide due to cleaning up their abandoned plum pickling pool. 22 people were poisoned and 6 died in 2009, a worker in an electroplating factory in Yangzhou caused hydrogen cyanide poisoning accident due to careless operation in the process of turning over and cleaning the brass tank, one person died and one person was poisoned in 2009, an acute hydrogen cyanide poisoning accident occurred among workers in a gold mine in Shandong Province during the cleaning of metallurgical cabin, and 11 people were poisoned in 2013, an acute hydrogen cyanide poisoning accident occurred in the cleaning process of semi-finished product storage tank of acetone alcohol plant in a factory in a city, 10 people were poisoned and 1 died in 2015, an acute occupational hydrogen cyanide poisoning accident occurred in the electroplating workshop of a hardware company in Shenzhen, one person was poisoned let’s know what hydrogen cyanide is today? What are the common contact opportunities? What is the toxic mechanism of hydrogen cyanide? What kind of clinical manifestation can hydrogen cyanide acute poisoning have? How can we prevent it what is hydrogen cyanide: hydrogen cyanide (HCN), with molecular weight of 27.03, is a colorless gas with bitter almond flavor at room temperature, which is easily soluble in water, ethanol and ether. 1ts aqueous solution is hydrocyanic, which is a highly toxic substance. 1t is acidic and reacts with alkali to form salt, namely cyanide. Usually people know that cyanide is inorganic cyanide, including hydrocyanic acid, potassium cyanide and sodium cyanide. However, organic cyanide is formed by cyano group combining with other carbon atoms through single bond, including acetonitrile, acrylonitrile, etc. Cyanide can release hydrogen cyanide gas at high temperature or when it interacts with acidic substances. Among cyanide, hydrogen cyanide is the most toxic, which is a kind of protoplasm poison with high activity, high toxicity and fast action. The adult lethal dose of hydrogen cyanide gas is about 60mg. When the concentration of hydrogen cyanide is up to 20-40mg / m3, a person may be slightly poisoned within a few hours. After exposure to 150mg / m3 for 30 minutes, he may die. When the concentration of hydrogen cyanide in the air is up to 300mg / M3, he may suddenly faint without any omen, resulting in “electric shock” death common contact opportunities: with the rapid development of China’s chemical industry, cyanide is more and more widely used and used more and more frequently. Cyanides commonly used in industry include hydrocyanic acid, potassium cyanide, sodium cyanide, ammonium cyanide, etc electroplating, mining and metallurgical industry: such as gold, copper and silver plating, cyanide enrichment, extraction of precious metals such as lead, zinc, gold and silver, quenching of steel and carburizing of metal surface production of cyanide containing compounds: such as hydrocyanic acid production, manufacturing other cyanide, drugs, synthetic fibers, plastics, rubber, plexiglass, paint, etc chemical industry: manufacturing various resin monomers, such as acrylic resin, methacrylic resin, ethylenediamine, acrylonitrile and other nitrile raw materials fuel industry: synthesis of cyanuric chloride, an intermediate of active fuel Photography: the waste liquid of photography processing contains ferrocyanide agriculture: such as fumigant, rodenticide, etc military: used as war agent daily life contact: for example, bitter almond, loquat kernel, peach kernel, cassava and ginkgo all contain cyanide mechanism and clinical manifestations of acute hydrogen cyanide poisoning: acute cyanide poisoning is mainly absorbed through the suction channel, followed by absorption through the skin at high concentration. Life cyanide poisoning is mainly oral, oral mucosa and digestive tract can be fully absorbed. After entering the human body, hydrogen cyanide can release cyanide ion (CN -) and directly combine with Fe3 + in cytochrome oxidase, inhibit the activity of the enzyme, make it lose the ability to transfer electrons, block the chain of absorption, and cause the cell to lose the ability to carry oxygen, resulting in “intracellular asphyxia”. 1n cyanide poisoning, although the blood is saturated with oxygen, it can not be used by tissues, the oxygen difference between arteriovenous blood decreases, and the skin and mucous membrane are cherry red clinical manifestations of acute hydrogen cyanide poisoning: (1) contact reaction: the patient has headache, dizziness, fatigue, chest tightness, and can also be accompanied by eye and suction tract irritation symptoms, which are mostly transient and can recover quickly after contact(2) Mild poisoning: mainly manifested as chest tightness, palpitation, heart rate acceleration, headache, obvious bitter almond taste in exhalation, nausea, vomiting, visual and physical model burning(3) Moderate poisoning: aggravation of the above symptoms, shortness of breath, decrease of blood pressure and bright red skin(4) Severe poisoning: the main manifestations were deep coma, shallow and fast breathing, rapid heart rate, arrhythmia, paroxysmal convulsions, and even severe disturbance of consciousness. High concentration or large dose intake can cause electric shock like death principles of emergency treatment: (1) immediately leave the scene to a place with fresh air, quickly implement treatment, and provide oxygen therapy as soon as possible (2) remove the contaminated clothes and wash the contaminated skin with clean water or 5% sodium thiosulfate< (3) the patients who were ingested through digestive tract should immediately induce vomiting and lavage their stomach with 1:5000 potassium permanganate or 5% sodium thiosulfate solution (4) in case of eye pollution, wash with plenty of flowing water or normal saline immediately< Preventive measures: (1) the production process should be reformed to replace toxic raw and auxiliary materials with non-toxic raw and auxiliary materials< (2) innovate production equipment, strengthen equipment management and maintenance. The process that may produce cyanide should be closed, mechanized and automated to prevent running, emitting, dripping and leaking< (3) establish occupational health management system and operating procedures. At the same time, the emergency rescue plan suitable for the enterprise should be formulated, and drills should be organized regularly to strengthen the emergency rescue ability< (4) enterprises should strengthen the personal protection of operators. Workers exposed to cyanide should wear practical protective equipment< (5) ventilation and detoxification. Mechanical ventilation facilities should be installed in indoor workplaces exposed to cyanide, and it should also be used as accident ventilation. The ventilation frequency should not be less than 12 times / h< (6) strengthen the management of limited space operations. We should implement the permit system for work in limited space, strictly implement the occupational hazard protection standards for work in limited space, and prevent workers from occupational hazard accidents such as hypoxia and acute poisoning< (7) strengthen occupational health education and training. Occupational health training should be carried out for workers exposed to cyanide to enhance their awareness of the toxic effect of cyanide and their awareness of protection, so as to prevent occupational hazards

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