With the development of modern industry, the occupations exposed to irritating gases are more and more extensive. In recent years, due to the improvement of production equipment and the improvement of employees' safety awareness, irritating gas poisoning incidents have a downward trend. However, there are also a few enterprises and individuals with weak awareness of safety in production, which often leads to poisoning incidents. Therefore, it is necessary to study the rules, causes and treatment principles of irritating gas poisoning by analyzing typical cases, so as to provide scientific basis for prevention, control and response to such poisoning incidents.
1, general situation of irritating gas poisoning
Irritant gas is a kind of harmful gas that can irritate skin, eyes and respiratory mucosa. It is the most common harmful gas in industrial production. Due to the corrosiveness of irritating gas, in the production process, equipment and pipelines are often corroded or accidents lead to running, running, dripping and leakage, resulting in gas escape and acute poisoning. Long-term low-concentration exposure will also have a chronic impact on health.
There are hundreds of irritating gases, some of which are not gases under normal circumstances, but can act on the human body through evaporation, sublimation and volatilization of steam and gas. Common irritating gases are chlorine, ammonia, nitrogen oxides, phosgene, hydrogen fluoride, sulfur dioxide and sulfur trioxide.
Contact opportunity:
1. Chemical industry: such as manufacturing nitric acid, synthesizing nitro explosives, nitrocellulose and aniline dyes.
2. Mine blasting. 3. Welding industry: such as electric welding, gas welding, argon arc welding, gas cutting, etc.
4. Agriculture: improper storage of green feed, like "barn gas poisoning".
5. Others: such as metal pickling, exhaust gas from internal combustion engine, etc.
2. Typical irritating gas poisoning events
2. 1 acute chlorine poisoning
1September, 1998, 33 people were poisoned by chlorine leakage in a paper mill. At that time, a worker in the factory found that the valve of the liquid chlorine tank for bleaching was leaking, so he pushed it into the lime pool for bleaching pulp and added water and quicklime to neutralize it. At that time, the liquid chlorine content in the tank was about 600kg. The next night, the gas leakage became more serious and spread to the whole factory. The personnel on duty continue to add water and quicklime to the pool, and the gas leakage is heavier and spreads around. In the early morning, the staff on duty and the factory director saw that the situation was not good, so they went to a nearby middle school and village to wake up the sleeping people and evacuate. However, many villagers are still poisoned. In the accident, 33 people were poisoned, of which 1 died, and the remaining 32 people were sent to the hospital in time.
The clinical manifestations of poisoned patients after being sent to hospital are: tears (20 cases), dry cough (23 cases), conjunctival congestion, nasal congestion, pharyngeal congestion (15 cases), chest tightness and dyspnea (14 cases), dizziness, headache (10 cases), coma and shock. After spasmolysis, sedation, dehydration, acidosis correction, oxygen inhalation, anti-infection and hormone therapy, 20 cases were basically cured, and 32 cases were all cured except 1 case.
Cause analysis of the accident: The factory is a village-run enterprise, using several simple offices in the administrative village as workshops, with an annual output of 2,000 tons of toilet paper, and adopting the eliminated chlorine bleaching pulp production process.
In recent years, township enterprises have developed rapidly and farmers have entered factories. Most of them lack basic knowledge of safe operation. Most village-run enterprises have a low level of leadership education, weak awareness of safety production, and lack of occupational health knowledge and self-protection awareness. Once an accident happens, if you don't know how to help the poisoned person and yourself, or even make a wrong judgment and take the wrong measures, it will expand the harm of the accident. Some township enterprises contracted by individuals have poor equipment conditions, unreasonable site selection, no corresponding safety protection measures, insufficient understanding of the harm of chlorine gas, and only pay attention to the economy while ignoring pollution and hidden dangers, which are the main reasons for this accident.
2.2 Acute ammonia poisoning
On July 1 1, 2002, an ammonia leakage accident occurred in a cold drink factory in Baoding, Hebei Province. At 10: 30 that night, the ammonia valve pipe of the freezer in the factory suddenly burst, leaking a lot of high-concentration ammonia water and ammonia gas, causing four workers to inhale high-concentration ammonia gas for a short time on the spot, resulting in three deaths. It was diagnosed as second-degree burn, with obvious signs of burns on the head and neck of both upper limbs, and the rest were normal. After symptomatic treatment such as oxygen inhalation and anti-infection, he recovered and was discharged.
On-site inspection shows that a strong ammonia smell can be smelled at a distance of 0/0m from the workshop/kloc-. After testing, the ammonia concentration is 50 mg/m3. There are no ventilation and detoxification facilities, ammonia alarm devices and emergency rescue measures, and no personal anti-virus supplies in the workshop of this factory. After asking the person in charge and the staff, it was confirmed that the enterprise did not arrange the workers for occupational health examination, did not train the workers for occupational health, and the workers lacked self-protection knowledge.
2.3 Acute sulfur dioxide poisoning
1997165438+1October 51kloc-0/20, an acute sulfur dioxide poisoning accident occurred in the sulfuric acid drying tower of chlorosulfonic acid branch of a factory due to improper command and coordination and illegal operation. During the shutdown and maintenance, an employee accidentally dropped his safety helmet on the lower floor of the drying tower. At this time, because the temperature of the roaster has dropped below 560℃, it needs to be burned in the air to raise the temperature. At this time, the worker violated the operating rules, put on a gas mask, climbed into the hole to get the lost helmet, and fell into the tower poisoned during the period. The worker died after being rescued.
The main cause of the accident is that the workers violated the operating rules, followed by lack of safety and health protection knowledge and improper use of protective equipment. According to the sampling analysis after the accident, the SO2 content in the drying tower is as high as 13000mg/m3, which is 886 times higher than the allowable SO2 concentration in the air of the workshop (15mg/m3). In such a high concentration environment, the filter gas mask has completely lost its protective function.
2.4 Poisoning by mixed harmful gases
In June, 2000, 48 patients with mixed harmful gas poisoning were treated in a hospital of a mining bureau. 66 people were poisoned, including 4 people who died at the scene/kloc-0, and 3 people died in provincial hospitals. There were 65 males, female 1 case, age 18 ~ 55 years old, with an average of 36.2 years old. The exposure time of harmful gas is 1 ~ 16 hours, and the treatment time is several hours to one week. According to the principles of diagnosis and treatment of occupational harmful gas poisoning, the condition was graded. Mild poisoning was 3 1 person, moderate poisoning was 9, and severe poisoning was 9, among which mild poisoning 16 were ambulance personnel.
Mild poisoning is characterized by dizziness, headache, chest tightness, fatigue, runny nose, sore throat and cough, and CT examination of brain and lung is basically normal. Liver and kidney function damage and EEG abnormality occurred in 6 cases. Moderate and severe poisoning is characterized by partial confusion, lethargy, vomiting, dyspnea, fever and incontinence; 16 cases had liver and kidney function damage; 13 patients had abnormal EEG; 18 patients had abnormal CT in brain and lung; 5 cases of local soft tissue congestion and edema; 1 case has pulmonary hypofunction and cardiac insufficiency; The common peroneal nerve was damaged in 3 cases; 1 case with limb necrosis complicated with acute renal failure; 1 case has toxic mental disorder; 1 case of adult distress respiratory syndrome. Compared with simple CH4 poisoning, this kind of poisoning has the characteristics of less coma, more muscle congestion, more swelling and more peripheral nerve damage.
The accident was caused by the gas produced by the burning of conveyor belt in coal mine. The main components produced after combustion include H2S, SO2, Cl2, phosgene, HCl, CO, CO2, CH4, etc. Among them, H2S, SO2 and HCl are irritating gases, while CO, CO2 and CH4 are suffocating gases. After poisoning, keratitis, pharyngolaryngitis, acute upper respiratory tract infection and cerebral hypoxia may occur, and in severe cases, dyspnea, coma, brain edema, pulmonary edema, skeletal muscle degeneration and even necrosis may occur. Acute renal failure, adult respiratory distress, toxic mental disorder. Facts have proved that early improvement of hypoxia and ischemia, protection of multiple organ functions, early detection, early analysis, early diagnosis and early treatment, and prevention and reduction of complications can achieve curative effects.
3. Clinical manifestations of irritating gas poisoning
There are many kinds of irritating gases that can cause poisoning, and their clinical manifestations are similar, mainly acute poisoning:
(1) Local irritation symptoms, such as tears, photophobia, conjunctival congestion, sore throat, choking cough, chest tightness, etc.
(2) Laryngospasm and laryngeal edema can suddenly lead to severe dyspnea, cyanosis and even sudden death due to hypoxia and suffocation. Laryngeal edema occurs slowly and lasts for a long time.
(3) Chemical bronchitis, bronchitis and pneumonia, severe cough, chest tightness and shortness of breath.
(4) Toxic pulmonary edema can go through stimulation period, incubation period, pulmonary edema period and recovery period.
4, processing principles and measures
Because the clinical symptoms of irritating gas poisoning have many similarities, so do their treatments.
(1) To prevent the poison from being absorbed, the patient should be evacuated to a place with fresh air immediately, take off the contaminated clothes, and wash the contaminated skin thoroughly with plenty of water quickly.
(2) Symptomatic treatment can achieve sedative, spasmolytic, antitussive and expectorant effects.
(3) The most serious hazard is pulmonary edema, which is urgent and changes rapidly. Therefore, active prevention and treatment of pulmonary edema is the key to rescue irritating gas poisoning.
5, preventive measures
Most irritating gas poisoning accidents can be avoided, and taking active preventive measures can at least reduce its incidence or reduce its harm.
(1) Strengthen the supervision and management of production units, and suggest that all units regularly overhaul production equipment to prevent running, running, dripping and leaking irritating gases. Supervise the production units to do a good job in the protection of occupational contact people.
(2) Factories that illegally use irritating gases must be resolutely banned and severely cracked down to ensure that the personal safety of workers is not violated.
(3) Strengthen health education, provide health education to personnel who are in close contact with irritant gases, prevent irritant gas poisoning, and guide them to operate according to operating procedures and strengthen personal protection. Educate employees to know how to deal with sudden irritating gas poisoning.
(4) If you suffer from chronic bronchitis, bronchiectasis, asthma and other diseases, it is recommended not to engage in irritating gas operations.
If the above procedures can be observed from the production unit to the individual employees, occupational irritating gas poisoning will be minimized.