Chapter 1 Chemical Accidents

First, the concept of chemical accidents

After a large number of chemical poisons are discharged or leaked, they contaminate air, water, ground and soil or food, and thus enter the human body through the respiratory tract, digestive tract, skin, or mucous membranes, causing group poisoning and even fatal accidents. These are chemical accidents. In sum, a chemical accident is an accident or dangerous event that releases one or more substances. Chemical accidents are obviously social, sudden and hazardous.

The earlier recorded chemical accidents can be exemplified as follows.

80 years ago, December 7, 1917, the French ship "Monte Blanc" was entering the Port of Halifax Nova Scotia (Nova Scotia), to the British "Hay Fry No." Cruiser meets. The "Mont Blanc" cargo ship is loaded with TNT , picric acid, collodion and benzene needed in the European battlefield . The ship and "No. Imogen (Imo)" Belgian ship collided in the harbor, followed by a strong explosion occurred, causing great loss of life and property. The explosion can be felt 96 kilometers away, and the total death toll has never been confirmed, but it is about 2,000 to 4,000 . On the morning of the accident, Halifax

Of the 550 children in a school in the city , only 7 survived. About 800 people were injured in the city , 25,000 people were made homeless, and the city center was razed to a 4 km radius . As the person responsible for shipping the courage to take action, on the positive anchored in the harbor, "No. Pike Tuo (Pictoa)" British ammunition ship, and open up the sea gate, so that any drift boat, cargo ship and sank in minutes , and to avoid the second big explosion did not make this disaster cause even greater serious consequences. Afterwards, trains were used to transport medical supplies and doctors from Boston and New York. The medical camps allowed women and children to live.

In the 80 years, it has experienced various chemical accidents of various sizes, which have brought many disasters to humanity. In recent years, the impact of methyl isocyanate leakage from the U.S. joint carbide company Bhopal plant in India, China The " 8 · 5 " explosion accident in Shenzhen , China's Wenzhou Electrochemical Plant chlorine cylinder explosion and so on. According to a 1988 publication, only 3,150 bodies were left behind in the Bhopal incident, and 45,000 were left without permanent death , and 600,000 people were seeking compensation. More than the total number of deaths in chemical accidents reported in more than 40 years worldwide .

Second, the characteristics of chemical accidents

In order to illustrate the characteristics of chemical accidents, we will now illustrate them with typical examples.

1993 at 13:25 on August 5, located in the northeastern part of the river water in Shenzhen City of Trade Transportation Company-owned storage of dangerous goods (an area of 876 hectares), due to the chemical ammonium nitrate combustion explosion, 12 warehouse fire, surrounded by buildings Things were destroyed to varying degrees. 15 people died in the accident , 174 were injured and 8 were missing . The direct economic loss is about 240 million yuan.

(1) The cause of the explosion accident The Shenzhen Qingshuihe dangerous goods warehouse was originally a warehouse for storing and transporting general materials. It did not have the conditions for storing hazardous materials, but stored a large amount of yellow phosphorus, alcohol, diphenyl, xylene, and propanol. Paints, matches, and other flammable products; and stored explosives such as ammonium nitrate and infusible powder. The direct cause of combustion explosion is that the contact between oxidant and reducing agent in the No. 4 warehouse is self-igniting and burning, and the fire can not be controlled in time due to the explosion burning for 16 hours, which causes the whole warehouse to burn and explode.

(2) The main measures taken at the scene of the explosion were first organized to extinguish fires. 1,500 armed police officers were organized to build a wall with 130 tons of bagged cement to separate 230 tons of hydrogen peroxide in the warehouse from the fire area. explosion.

Timely evacuation of residents near the scene of the accident is a major measure to avoid casualties. The second blast occurred at 14:26, a large force of the explosion, mushroom cloud explosion fireball shape and form of the atomic bomb similar cause greater casualties.

It is not difficult to see from the above-mentioned cases that chemical accidents have the following salient features:

1 Accidents caused by accidental discharge or leakage of chemical substances cause human casualties and heavy losses.

2 Chemical accidents not only have chemical damage but also have diversity of damage, that is, chemical accidents can cause death or cause temporary or permanent functional or organic damage; they can also be acute poisoning. Is chronic poisoning; not only affect their own but also affect future generations; can be teratogenic can also cause cancer.

3 Chemical accidents Due to the wide distribution of various poisons and the high number of accidents, the pollution is serious. After the environment is contaminated, it is extremely difficult to eliminate them.

4 Chemical accidents are not affected by terrain, weather and seasons. Regardless of the size of the company, weather conditions, and whether it is spring, summer or autumn, chemical accidents can happen anywhere, anytime.

5 There are many types of chemical substances, and it is estimated that there are 5,000 to 10,000 species. Therefore, it is very difficult to determine which substance causes it. It is difficult to confirm the diagnosis.

6 Chemical accidents are caused by poisons and can also be caused by chemical explosions and fires.

Third, the consequences of chemical accidents

Chemical accidents often occur in the storage of chemical companies or chemical substances. They also occur during poisoning or explosion and combustion. There are many causes of chemical accidents. There are a wide variety of chemical products, a variety of materials, more than 30,000 kinds of products, and the causes are complex. There are both internal and external causes, both cause and production. Inevitable equipment reasons. Chemical accidents cause explosions and burning, or poisoning, and often endanger the safety of people’s lives and property, with incalculable and serious consequences.

1. Poisoning

Sudden chemical accidents can often lead to poisoning of many people and even many deaths. They are often referred to as major catastrophic accidents. If there are more than 100 poisoned persons and more than 30 deaths occur , they will be catastrophic accidents.

Chlorine cylinder explosion September 7, 1979 in Wenzhou of Zhejiang Province Hydro plant occurred, causing the death of 41 people, the number of out-patient admitted poisoning 779 people is an example. September 3, 1991 methylamine 2.4 tons spill occurred in Jiangxi Shangrao lead to death 41 people is case in point.

Substances that cause chemical accidents include the following types: gases ( eg, asphyxiating gases carbon monoxide, cyanide; irritants such as nitrogen oxides, chlorine, ammonia, sulfur dioxide, dimethyl sulfate, etc. ) , organic solvents ( aniline, trinitrotoluene). Etc ) , as well as organophosphorus pesticides.

Of course, there are no fewer than a dozen or even hundreds of chemical accidents that can cause chemical accidents in common chemicals. However, the substances that can cause chemical accidents must have basic conditions, that is, the poisons are easily dispersed, and more people are exposed when they are distributed. . From the actual situation,

Chemical accidents are mostly concentrated on certain chemical substances: chlorine gas, ammonia gas, nitrogen oxides, carbon dioxide, hydrogen sulfide, dimethyl sulfate, phosgene, etc. They are mainly composed of irritating gases and asphyxiating gases and account for all poisoning accidents. more than 75%. Among them, the chemical accidents caused by chlorine, carbon monoxide, and ammonia are about 55 percent.

The proportion of these poisons is not difficult to understand. First of all, they are the most basic raw materials in chemical industry, such as chemical fertilizers, chlor-alkali, synthetic fibers, oil refining, dyes, medicine, and military production. They are also products and by-products. In the chemical, petrochemical, petroleum and other industries, applications and contacts are very common and harmful. Secondly, because the irritant gas can generate acid or alkali when it meets water, it is highly corrosive. It often causes damage to equipment and pipelines, running, running, dripping and leaking. The escape gas can easily enter the human body through the respiratory tract and cause human poisoning. .

2. Explosion and burning

Explosion and combustion are another important cause of chemical accidents. From 1949 to 1984 , 5899 chemical accidents occurred in the nation's petrochemical enterprises , and equipment causes accounted for a large proportion. The following characteristics can be seen from the explosion and combustion accidents that occur in a large number of chemical equipment.

1 Accidents are common. Between 1979 to October 1988, according to the country's 28 provinces and fertilizer, chemicals, oil refining industry to incomplete statistics, a total explosion occurred chemical equipment and machine 252, accounting for 45.7% of all accidents, mostly due to illegal command and Operation, equipment defects, low quality of operators.

2 The same accident occurred one after another, and the same accident occurred on the same device.

For example: Overpressure explosion of the gas boiler water jacket; before shutting down and maintenance, failed to replace or replace unqualified, blindly moving fire; not isolated from the production equipment, causing a fire explosion.

3 Major accidents occur from time to time. August 29, 1989, a chemical plant PVC plant equipment manhole and shaft at the Benxi City in Liaoning large spills, combustion caused the explosion, the death of 12 people and injuring five people.

April 15, 1972, a transport of ammonia fertilizer plant in Shanxi Province tanker explosion on the way, the death of 21 people, injured 56 people, slightly injured 99 people.

4 equipment defects serious

a. In the equipment defects, due to design problems caused by equipment defects, in particular, caused by combustion and explosions are common occurrences, from 1982 to 1986 compressor accidents due to design accounted for about 50 %.

b. The material does not meet the requirements, the quality of casting and welding is poor, and the quality of the valves leads to accidents.

c. Cylindrical cracking accounts for 64 % of all cylinders due to design and manufacturing defects .

IV. Management of Chemical Dangerous Goods and Emergency Management

The history of the development and progress of human society is the history of human beings fighting various kinds of disasters. It is also the history of mankind’s development in overcoming disasters. Similarly, the progress of human society is inseparable from the progress of science and technology ( including the progress of chemical development ) .

Chemical accidents and their medical rescue are a kind of medical rescue, that is, disaster medicine. Chemical accidents cause serious damage to human life and property, and chemical accidents and their rescue are very urgent. It is necessary to strengthen management.

At present, all countries in the world and China have strengthened the legal construction of chemical accidents, the reform of the rescue system, and other improvements.

( I ) Foreign Situation

Due to the occurrence of a series of chemical accidents, it has caused tremendous catastrophes to human life, health and the environment. It has been called “destructive,” especially after the Bhopal incident in India in 1984 , which shocked the world. They have adopted a series of measures, decisively revised laws and regulations, invested funds, and strengthened training.

United States: After the Bhopal accident and the rupture of ethylene and propylene tank pipelines in Mexico City, the disasters and impacts that these accidents themselves brought to the Indian people, Mexico, and the United States itself forced the United States to adjust many laws and regulations to take effective measures. To stop the occurrence of accidents, many new national and local regulations have been introduced;

In January 1986 , the New Jersey State Poison Prevention Act was issued;

In September 1986 , the "Toxic Accident Leakage Accident Detection and Prevention Plan" was issued;

In June 1986 , the "Delaware State Risk Management Act for Extremely Hazardous Substances" was issued;

In November 1989 , the US Center for Chemical Process Safety issued the "Guidelines for the Management of Chemical Process Safety Technologies";

In 1990 , the American Petroleum Institute released "Process Safety Management Standards";

February 1992 OSHA issued "highly hazardous chemical process safety management";

In 1992 , the "Nevada Chemical Disaster Prevention Plan" was issued;

In 1996 , the EPA issued the "Risk Management Suggestion Plan."

In addition, OSHA has developed a number of effective laws and regulations based on a total of 25 million workers in the United States and more than 600,000 occupations related to hazardous chemicals. The most famous of these is the OSHA Law, requiring:

1 Each chemical dangerous goods should have a handover system.

2 Each company must provide MSDS , which is the safety and health data of each substance.

3 It is necessary to provide each employee with safe and hygienic technical training and education. In particular, the employees of chemical dangerous goods shall be trained for 40 hours per year , and only after obtaining the certificate can they be employed .

4 Perform regular medical examinations and health monitoring on employees. In addition, OSHA has also prepared the "Management Criteria for Federal Chemical Dangerous Goods" and proposed:

1 Employers cannot cause employee injuries and occupational diseases due to factors such as the operation of various devices, items, and equipment.

2 Each employee should observe occupational safety, hygiene, standards, regulations, rules, and orders.

In 1986 , the United States Congress passed an amendment to the SUPERFUND Law, which is the "highest legal basis for emergency rescue of chemical accidents." The third part of the law is "Contingency Planning and Public Awareness ." The main contents are as follows.

1 Organization. At the federal and state levels, the Chemical Accident Emergency Response Committee (FERA) was established to set up an Emergency Response Team (NRT) .

The Federal Emergency Response Committee consists of the following organizations: EPA , OSHA , Ministry of National Defense, Ministry of Commerce, Ministry of Agriculture, Ministry of Communications, Public Health Administration ( Ministry of Health ) , Federal Emergency Management Agency.

The emergency response committees in the states are basically the same as the federal ones, except for different positions.

2 Develop and promulgate lists of extremely hazardous chemicals and threshold limits. Any enterprise, as long as it produces, stores, and uses any material on the list, must report it to the local emergency response center and the fire department within 60 days. If it does not declare, the competent department will impose a heavy fine.

3 specifies the content of declarations of extremely hazardous chemicals.

4 specifies the procedures for reporting hazardous chemicals.

5 The day-to-day management of hazardous chemicals and their responsibilities to society are stipulated.

6 Enterprises that produce and use hazardous chemicals shall submit annual reports to the EPA and OSHA each year.

Attachment: Emergency Rescue Organization Block Diagram

1. Structure diagram of emergency response organization for chemical accidents in the United States

The daily offices of NERA and LERA are located at the EPA and are responsible for the emergency management of major chemical accidents, hotline consultations and handling of major accidents.

2. Emergency agencies and personnel

Both the federal and state establishments have emergency response committees, the Federal Emergency Response Council or ( reaction committee ) response center, and the state is called the response team. They are mainly responsible for the emergency management of major chemical accidents, hotline consultations, and the assessment and inspection of daily major hazards.

3. Emergency Management and Technology

(1) Preventive measures LERA registers the management of major chemical accidents. The production and storage facilities for the devices, processes, and extremely hazardous chemicals identified as major sources of danger shall be reported to the local emergency response committee for registration. The content is as follows:

The design of new or extremely hazardous chemicals in service (FSH) to conduct security checks, you must first determine the list of FSH and evaluation;

Establish standardized operating procedures;

Establish strict maintenance procedures;

Establish strict accident investigation and research procedures;

Risk assessment of each facility that produces and stores FSH ;

Prepare an emergency rescue plan.

For the assessment of major hazard sources, four aspects of work should be carried out;

Estimation of leakage;

Leakage probability analysis ( accident tree, disaster pre-distribution ) ;

Vapor diffusion analysis;

Consequence impact analysis.

(2) emergency rescue tools and medical care in order to control the American Association of chlorine chlorine leak accident during transport for 100 to 150-pound cylinder, one-ton cylinders and tanker train in three different size containers, developed three Different sizes of containers are prepared for emergency backup when the cylinders are leaking. The effect is very good. In North America, 15,000 sets have been sold . Major companies are equipped with emergency rescue tool carts, and some respond with computers, telex, communications equipment and protective equipment, emergency plugging tools and on-site monitoring equipment. The medical rescue of major chemical accidents is very important and is generally undertaken by public medical institutions. Medical institutions equipped, better conditions, once the chemical accident will be according to the scene and the relevant information quickly mobilize the nearest medical center, to the scene to rescue response.

(3) Emergency response and information system Emergency rescue of chemical accidents forms a hotline network in the industry and in the region. The telephone is open 24 hours a day and accepts hotlines from all sides at any time.

More important hotline:

Chemtrae , started for the American Manufacturers Association in 1971