(1) Close the valve, stop the leakage and cut off the accident source.
After the fire brigade arrives, if the poison is still leaking, it should know the name, physical and chemical properties, poison types, production technology and technical requirements of the leaked poison from the person in charge of the accident unit and relevant technicians in time, and actively cooperate with relevant technicians and skilled workers of the accident unit to cut off the accident source under the premise of strict protective measures after carefully studying the implementation plan of valve closing and plugging. The following points should be paid attention to when implementing the disposal measures of closing the valve for plugging and cutting off the accident source:
1, rescuers must wear chemical protective clothing before entering the scene of the accident (air respirator, heat insulation clothing or fire protection clothing should be worn in case of burns and high temperature). Before wearing it, they should carefully check its intact condition, and be supervised by a special person (record the pressure of gas cylinders in air respirator, the names of people entering and leaving, the entry time, etc. ). When necessary, people entering the site can be covered with flowers or misty water to ensure the safety of rescuers.
2. If it is a leakage accident in the production process, firefighters can work with people who are familiar with the accident unit. Firefighters will follow up the coverage by flowering or spraying water, assist them to close the pipeline valve for conveying materials and cut off the relevant power supply and fire source, and be sure to prevent the valve from leaking by mistake. For example, in August, 2000, the fire at Kenshin Chemical Plant in Jiangmen was put out.
3. Special soft rubber plugs (such as cone plugs and wedge plugs), cork, clay, cotton wool and soap can be used to plug the container wall and pipeline wall, and wet cotton wool can also be used to plug and bind the larger holes. It should be noted that it is generally not easy to close the valve or switch first when directly blocking the leakage of the container in the chemical process flow, but appropriate cooling and depressurization measures should be taken under the guidance of the engineers and technicians of the accident unit according to the specific situation (our fire brigade can implement uniform flowering water cooling under the guidance of the technicians), and then close the valve and switch to stop the leakage, so as to prevent the pressure and temperature in the container from suddenly rising and exploding.
4. For toxic and harmful substances that cannot be stopped immediately and continue to leak out, they can be mixed with water or corresponding solutions according to their nature, so that they can be quickly detoxified or diluted. For example,1In the early morning of July 6, 1995, a large amount of chlorine gas leaked from the sewage treatment room of a hospital in Chengdu, and a large amount of quicklime was put into the pool, which successfully handled the accident.
5. When leakage burns, as long as it is stable, generally don't rush to put out the fire. Instead, water guns are first sent to cool and protect leaking combustion containers, pipelines and their surrounding containers, pipelines, valves and other equipment, as well as buildings and structures threatened by flame and high temperature. Only when you are fully prepared and are sure to handle the accident well can you put out the fire.
6, the transfer of inflammable and explosive dangerous goods at the scene of the accident or take protective measures, must be carefully carried out in accordance with the relevant requirements and procedures, to prevent the accident from expanding due to blind recklessness.
(two) serious testing, strict control of polluted areas.
After the chemical accident, the full-time staff of the fire brigade or the professional technicians of the chemical defense forces, environmental protection, health and epidemic prevention, chemical enterprises and toxic gas detection equipment should sample and detect the accident site and its surroundings as soon as possible. When the types of leaked poisons are known, we should quickly find out the scope of poison pollution and its concentration in air and water, and mark the boundaries between key protection targets and accident areas according to the measurement results. When the types of poisons are unknown, samples should be sent to monitoring institutions for analysis and determination. Detection can adopt the method of combining fixed-point detection with patrol detection, and residential areas and traffic arteries should be the focus of detection. The detection work should run through the emergency rescue. It is necessary to report the test results to the field headquarters in time. So as to provide scientific basis for the headquarters to effectively organize and carry out various rescue work. At the same time, the emergency rescue headquarters quickly mobilized the public security, armed police, militia or garrison to delimit the warning zone, set up sentry posts at the border of the warning zone or set up warning lines by planting flags, spreading lime lines and pulling ropes to strictly control the polluted areas. Prevent people and vehicles outside the polluted area from straying into the polluted area and causing injuries. Public security traffic police should set up checkpoints at major traffic arteries and intersections in polluted areas and their vicinity, control the entry and exit of irrelevant vehicles and personnel, and ensure the passage of emergency rescue vehicles. It is necessary to maintain social order in the polluted area and its vicinity, inform the masses of the accident situation and disposal measures in a timely manner, do a good job in publicity and education, stabilize the mood of the masses, and prevent social chaos caused by mass panic and bad rumors. Especially for the important targets and parts of the polluted area, we should strengthen security and prevent the enemy from destroying them.
(3) Rescue poisoned personnel, evacuate and protect the masses.
In the event of a chemical accident, the fire brigade should actively take the following measures with the cooperation of the accident unit and relevant parties to quickly rescue the poisoned personnel and evacuate and protect the personnel in the polluted area.
1. The commando team (group) to rescue the poisoned personnel should carry the poisoned personnel out of the contaminated area as soon as possible (relay transmission can be used when the distance is far away) and transfer them to a safe place. When toxic substances splash into eyes, they should be washed repeatedly with clear water immediately. Due to the damage of toxic substances, it often causes serious obstacles to human function, such as respiratory failure, shock, pulmonary edema and acute renal failure. On-site medical rescue teams should promptly rescue and treat poisoned personnel. And try to use special antidote to detoxify, as well as enema, eye washing, water washing and other auxiliary means to seize detoxification and detoxification. After taking corresponding rescue measures for the seriously injured who are difficult to rescue at the scene, we should organize forces in time and send them to relevant hospitals for treatment. In the process of escort, we should pay attention to observe the condition of the wounded and take rescue measures constantly.
2. While actively rescuing the poisoned personnel, the emergency rescue headquarters should notify the units and people in the polluted area by telephone, radio, television or sending several evacuation groups (composed of fire fighting troops, garrison troops, health and epidemic prevention and medical personnel), and evacuate the polluted area quickly and orderly under the guidance of the evacuation groups. Before organizing evacuation, the inspection team (detachment) should report the inspection situation to the on-site headquarters in time and accurately, so as to formulate the best evacuation plan and determine the best evacuation route. If the detection conditions are limited, people in the polluted area can be organized to evacuate in the direction of headwind or crosswind as much as possible. You can also use nearby civil air defense fortifications or closed buildings for shelter. In case of emergency, indoor personnel who can't be evacuated temporarily can be organized to close doors and windows temporarily, and stay in the leeward end of the house, doors and windows openings and rooms with few gaps as far as possible. Outdoor people or pedestrians can wear masks or cover their nose and mouth with wet clothes, towels, handkerchiefs and other fabrics (even with their own urine). It would be better if the lid could be coated with soap. For example, from February 25th 1995 to February 5th 1996/kloc-0, a huge natural gas blowout occurred in "Du 1 well" in Xuanhan County, Sichuan Province. Due to the high content of hydrogen sulfide in the external spray column, all officers and men of Sichuan Fire Brigade wore two or three layers of masks and soaked them in water when a large number of oil workers and surrounding people were poisoned.
(four) the implementation of decontamination, control and eliminate toxic pollution.
After a chemical accident, the roads and water sources around the accident site may be seriously polluted. If it is not washed in time, the pollution will spread rapidly and cause greater harm. This task is mainly undertaken by the fire brigade and chemical defense forces. When decontaminating, corresponding methods and detergents must be adopted according to their physical and chemical properties and the specific conditions of the contaminated objects.
1, decontamination method
One is chemical disinfection. That is, chemical disinfectants and toxic substances directly play the role of oxidation and chlorination, and toxic substances change their properties and become non-toxic or low-toxic substances. The disinfectant aqueous solution is filled in the water tank of the fire truck, pressurized by the fire pump, and sprayed by the hose and water gun in the form of flowering or water spraying.
The second method is combustion disinfection. That is, combustion is used to destroy toxic substances and their toxicity. This method can be used for facilities and articles that are of little value or can still be used after a fire. However, although burning can destroy poisons, it may also volatilize poisons, causing air pollution nearby and downwind, so personnel should take protective measures when using this method.
The third is physical disinfection. There are three ways of this method: (1) adsorption. That is, substances with good adsorption performance (such as special adsorption pad, activated clay, activated carbon, etc.). ) It is used to adsorb the surface of contaminated articles or filter toxic substances in air and water, as well as cotton and gauze. It can also be used to remove venom droplets visible on human skin; (2) solvent washing. That is, solvents such as cotton and gauze such as gasoline, alcohol and kerosene. Used to dissolve and scrub poisons on the surface of contaminated poisons; (3) mechanical transfer. That is, using cutting, uprooting or covering machinery (such as demolition tools, forklifts, bulldozers, etc.). ) Remove or cover toxic substances, so that personnel do not directly contact the contaminated articles and facilities.
2. Decontamination (disinfection) agents mainly include the following:
(1) chlorinated disinfectant. Such as calcium hypochlorite (also known as bleaching powder and chlorinated lime), sodium hypochlorite, triple-pair, chloramine, dichloramine, sodium dichloroisocyanurate, etc. This kind of disinfectant mainly achieves disinfection purpose through oxidation and chlorination. (2) alkaline disinfectant. Such as sodium hydroxide, calcium hydroxide, ammonia water, sodium carbonate, sodium bicarbonate, etc. (3) Physical detergent. Include common solvents such as water, alcohol, gasoline and adsorbents.
(4) Simple detergents, such as plant ash water and soap powder water. Because it contains alkaline components, it can also be used for decontamination.
3. Problems that should be paid attention to when choosing decontamination methods.
(1) The decontamination method should be selected according to the nature and state of toxic and harmful substances. For oily liquid poisons with high toxicity and long duration, chlorine oxide disinfectants or alkaline disinfectants are generally used for disinfection. Rinse with plenty of water after disinfection; General gas poisons may not be specially disinfected, but the polluted area may be temporarily closed. Depending on natural conditions such as sun exposure and ventilation, toxic gases may escape and disappear. For high-concentration polluted areas, some atomized disinfectant can be sprayed to speed up disinfection. (2) Choose the decontamination method according to the nature and pollution degree of the contaminated articles and facilities. For example, contaminated metal and cement structure production facilities can be disinfected by spraying disinfectants, and precision instruments and equipment can be wiped by organic solvents. However, no matter which decontamination agent and decontamination method are used, the principles of timely and thorough disinfection, as well as no damage to contaminated items as far as possible, and the restoration of their use value as soon as possible should be followed.
Special attention should be paid to the disinfection of fire-fighting vehicles and other vehicles, equipment and equipment involved in chemical accident rescue. Otherwise it will become a diffusion source. Personnel involved in emergency rescue should not only disinfect chemical protective clothing, combat uniforms, combat uniforms, used anti-virus facilities, testing instruments and equipment, but also thoroughly shower and rinse the body and skin, and pay attention to observe the physical condition and carry out health examination.