3 dead, 4 injured! An explosion occurred in a pharmaceutical company in Zhejiang!

According to the website of the Zhejiang Provincial Emergency Management Department, at around 9:30 am on November 20, 2021, an explosion occurred in the sewage treatment tank of Zhejiang Changming Pharmaceutical Co., Ltd. located in the Tiantai County Industrial Park, Taizhou City, resulting in 3 deaths and 4 injuries.

Previously, according to the Tiantai County Emergency Management Bureau of Taizhou City, Zhejiang Province, the cause of the accident was under investigation. According to preliminary monitoring, the accident had no impact on the surrounding environment.

Tianyancha information shows that Zhejiang Changming Pharmaceutical Co., Ltd. was established on September 13, 2006 with a registered capital of 50 million yuan. Its business scope includes raw material pharmaceutical production, organic chemical raw material manufacturing and sales, export business of the company's own products and technologies, and machinery and equipment, spare parts, raw and auxiliary materials required by the company.

The company was punished twice by the local Ecological Environment Bureau for storing hazardous waste mixed with non-hazardous waste, evading supervision and discharging water pollutants, and violating the Law on the Prevention and Control of Environmental Pollution by Solid Waste, with a total fine of more than 540,000 yuan.

According to the Taizhou Emergency Management Bureau, on September 29 last year, the company also held Tiantai County's 2020 comprehensive emergency drill for hazardous chemical accidents. The drill simulated the emergency response after a large amount of hydrogenated liquid leaked and exploded in the company's second workshop.

Usually in the process of sewage treatment

It will produce toxic, corrosive, flammable and explosive gases.

Risk prevention and control cannot be taken lightly

On July 11, 2020, an explosion occurred in the hydrolysis acidification workshop of the sewage treatment plant in the Fluorine Industry Development Zone of Fuxin, Liaoning Province, injuring 17 people.

On December 23, 2017, workers at a sewage treatment plant under construction in Wanding Town, Ruili City, Yunnan Province, were painting anti-corrosion materials in an anaerobic tank when the tank suddenly exploded, killing four workers on the spot.

On May 22, 2016, an explosion occurred at the Nancheng sewage treatment plant in Binzhou High-tech Zone, Shandong Province, causing a fire in the sewage plant's raw material storage warehouse and slightly injuring three people.

Safety Tips

Sewage treatment safety precautions!

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1. Anti-poison gas

During sewage treatment, toxic and harmful gases may exist in various pools and wells. A series of safety measures must be taken to prevent hydrogen sulfide poisoning.

(1) Understand the nature of sludge and clarify the source of sulfide pollution. Each pump station and sewage treatment plant should analyze the sulfide concentration of the influent. If it seriously threatens the safety of workers' lives, it should be reported to the relevant superior leadership department in a timely manner and effective measures should be taken.

(2) Regularly check the working environment, pump station collection wells, open outlet wells, and the hydrogen sulfide concentration in the lower pool and well treatment structures. The hydrogen sulfide concentration in the pool and well must be continuously monitored.

(3) Using ventilation blowers is an effective measure to prevent H2S poisoning. Ventilation can disperse H2S and reduce its concentration. Ventilation fans must be used in pools and wells. Attention must be paid to the fact that hydrogen sulfide is difficult to blow out due to its high specific gravity. When ventilating the pipeline, the adjacent well covers must be opened to allow one side to enter and the other to exit. For ventilation in the pump station, the fan should be installed on the bottom floor of the pump station to extract the poisonous gas.

(4) Equip with necessary anti-H2S equipment. Gas masks can prevent H2S poisoning, but targeted filter canisters must be selected.

(5) Establish a system for going down into the pool and into the well. Entering the bottom of the sewage collection pool to clean up garbage is a dangerous operation and a ticket for going down into the pool and into the well should be filled out in advance. It can only be carried out after being co-signed by the safety technician and approved by the grassroots leader.

(6) Safety education on preventing H2S poisoning must be provided to employees. Since hydrogen sulfide exists in sewers, pumping stations and treatment plants, employees must be made aware of the nature, characteristics, poisoning care and preventive measures of hydrogen sulfide.

2. Safe use of electricity

Regular safety inspections should be conducted on electrical equipment. The inspections include: whether the insulation of the electrical equipment is damaged; whether the insulation resistance is qualified; whether the exposed live parts of the equipment are protected; whether the protective neutral wire or grounding is correct and reliable; whether the protective devices meet the requirements; whether the portable lamps and local lighting voltages are safe; whether the safety appliances and electrical fire extinguishers are complete; whether the electrical connection parts are intact, etc.

For sewage treatment plant workers, the following safety requirements for electricity use must be observed:

(1) Only electricians can disassemble or install electrical equipment.

(2) Damaged electrical equipment should be repaired promptly by an electrician.

(3) The metal casing of electrical equipment should have an effective grounding wire.

(4) Mobile electrical appliances should use three-pin (four-pin) sockets and three-core (four-core) tough rubber wires or plastic sheathed wires. Outdoor mobile knife switches and sockets should be installed in a safe electrical box.

(5) Portable running lights must use a voltage below 36V, especially in humid places (such as trenches), the voltage must not exceed 12V.

(6) All temporary lines must be removed within a specified period of time and must not be connected without permission.

(7) Main electrical equipment should be used within the rated capacity.

(8) Electrical equipment should have appropriate protective devices or warning signs.

(9) Safe electricity operation procedures must be followed, especially the work permit system for maintenance and repair of electrical appliances, and necessary insulating tools must be used during operation.

(10) Regular safety activities should be carried out and knowledge on safe use of electricity should be learned. If someone is found to be electrocuted due to insufficient precautions, the first thing to do is to disconnect the person from the power source as soon as possible. After the person is disconnected from the power source, symptomatic treatment should be given promptly according to the specific situation, and medical help should be sought at the same time.

3. Prevent drowning and falling from heights

Employees of sewage treatment plants often work on sewage pools, so it is extremely important to prevent drowning accidents. To this end, the following are required:

(1) The sewage pool must have railings with a height of 1.2m.

(2) Workers are not allowed to cross the fence when managing sewage pools. Those who cross the fence must wear life jackets and be supervised by someone.

(3) When working on a sewage pool without railings, a life jacket must be worn.

(4) Several life buoys must be provided in the sewage pool area in case of emergency.

(5) The walkway on the pool should not be too smooth nor too uneven.

(6) If iron grilles, pool covers, or manhole covers are corroded or damaged, they must be replaced promptly.

In addition, sewage treatment workers should also know first aid methods for drowning.

Workers at sewage treatment plants sometimes need to work at heights. For example, changing a light bulb on a pool or working on the pool after draining the sewage pool is also equivalent to working at heights. When working at heights, you should remember the "three treasures" of working at heights (safety helmet, safety belt, safety net), and comply with a series of regulations for working at heights.

4. Laboratory Safety

Sewage treatment plants generally have water quality analysis laboratories. Laboratory work should comply with the following safety rules:

(1) When heating volatile or flammable organic solvents, it is prohibited to heat directly with flame or electric stove. It must be done slowly in a water bath or on an electric heating plate.

(2) Combustible materials such as gasoline, alcohol, kerosene, etc. should not be placed near gas lamps, electric stoves or other fire sources.

(3) When performing heating distillation and related work using fire or electric heating, at least one person should be responsible for management. Wear gloves when operating a high-temperature electric heating furnace.

(4) The wires used in electric heating equipment should be checked regularly to see if they are intact. Electric heating equipment should have suitable pads.

(5) The main power switch should be installed with a sturdy outer cover. When turning the switch on or off, never use wet hands and pay close attention.

(6) A storage and use system must be established for highly toxic drugs, which should be stored in a dedicated counter with two people and double locks.

(7) Strong acids and ammonia water should be stored separately.

(8) When diluting an acid, sulfuric acid must be added carefully and slowly to water, not water to sulfuric acid.

(9) When using a pipette to absorb acids, alkalis and harmful solutions, you cannot use your mouth to absorb them but must use a rubber bulb.

(10) Wear rubber gloves when pouring or using nitric acid, ammonia, and hydrofluoric acid. When opening a bottle of volatile reagents such as ether and ammonia, never point the mouth toward yourself or others. Especially in the summer, a large amount of liquid can easily rush out when opening the bottle, which can cause serious injuries if you are not careful.

(11) Any operation that generates harmful gases must be performed in a fume hood.

(12) When operating the centrifuge, the cover can only be opened after it has completely stopped rotating.

(13) Pressure vessels such as hydrogen cylinders must be kept away from heat sources and parked stably.

(14) After contact with sewage and medicines, you should wash your hands carefully. Do not contact sewage and medicines when there are wounds on your hands.

(15) The laboratory should be equipped with fire-fighting equipment, such as sand barrels and carbon tetrachloride fire extinguishers. The sand in the sand barrel should be kept dry and not soaked in water.

(16) The laboratory should be well ventilated and clean. At the end of each day, water and electricity safety checks should be carried out. In winter, anti-freeze measures should be checked before leaving get off work.

More science:

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Image source: China Fire

Source: Zhejiang Provincial Emergency Management Department, Beijing News, China Chemical Safety Association, China Emergency Management