Laboratory safety accident names, accident causes and preventive measures

Types of common laboratory accidents

1 Fire accidents

Fire accidents are common and may occur in almost all laboratories. The direct causes of such accidents are:?

① Forgetting to turn off the power, causing the equipment or electrical appliances to be powered on for too long and the temperature to be too high, causing a fire; (August 8, 2005, Capital A fire broke out in a laboratory of the Normal University. The cause of the fire: Wei, a master's student of the school, was doing experiments in the laboratory in the morning. He went out to eat at noon and did not turn off the power. The "rotor" of the experimental instrument was still running. The fire was caused by a short circuit in the wire)? ② The power supply lines are aging and overloaded, causing the lines to heat up and cause fire. ?③ Careless handling or improper storage of flammable and explosive items may cause the fire source to come into contact with flammable substances, causing fire. ?④ Throwing cigarette butts around and contacting flammable substances may cause fire.

2 Explosive accidents

Explosive accidents often occur in laboratories with flammable and explosive items and pressure vessels. The direct causes of such accidents are:

< p>① Using equipment and pressure vessels (such as high-pressure gas cylinders) in violation of operating procedures may cause explosions. ?② The equipment is aging, has faults or defects, causing leakage of flammable and explosive items, and causing explosions when encountering sparks. ③ Improper handling of flammable and explosive items, resulting in combustion and explosion; such items (such as trinitrotoluene, picric acid, ammonium nitrate, azide, etc.) are affected by high heat friction, impact, vibration and other external factors or other properties When conflicting substances come into contact, a violent chemical reaction will occur, producing a large amount of gas and high heat, causing an explosion. ?④ The mixture of strong oxidants and substances with conflicting properties can decompose, causing combustion and explosion. ?⑤ Explosion of instruments, equipment, medicines, etc. due to fire accidents.

3 Toxic accidents

Toxic accidents often occur in laboratories with chemicals and highly toxic substances and laboratories with toxic gas emissions. The direct causes of such accidents are:?

① Bringing food into a toxic laboratory, causing accidental food poisoning (for example: a staff member of a university in Nanjing accidentally put aniline-containing food in the refrigerator in midsummer) The intermediate product was drunk as sour plum soup and caused poisoning. The reason was that the refrigerator had stored sour plum soup for the staff to drink). ?② Equipment and facilities are aging, faulty or defective, causing leakage of toxic substances or failure to discharge toxic gases, leading to poisoning. ?③Poor management, careless or illegal operation, improper handling of toxic substances after experiments, resulting in the scattering and loss of toxic substances, causing poisoning of personnel and environmental pollution. ?④ The wastewater discharge pipeline is blocked or damaged, causing toxic wastewater to flow out without treatment, causing environmental pollution.

4 Mechanical and electrical injury accidents

Electromechanical injury accidents mostly occur in laboratories with high-speed rotation or impact movement, or laboratories that require live work and some experiments with high temperatures. room. The manifestations and direct causes of the accident are:?

① Improper operation or lack of protection, resulting in extrusion, throw-off, collision and injury. ② Violation of operating procedures or malfunctions and defects due to aging of equipment and facilities, resulting in electric shock due to leakage and injuries from arc sparks. ③ Improper use may cause harm to people from high-temperature gases and liquids.

5 Equipment damage accidents

Equipment damage accidents often occur in laboratories that use electric heating. The symptoms and direct causes of the accident are: ?

Due to a sudden power outage due to line failure or lightning strike, the heated medium cannot be restored to its original state as required, causing equipment damage. For example: Not long ago, two scrapping accidents of about 20 mercury electric tubes (with a loss of about 15,000) occurred in a university in Hunan, which were caused by sudden power outages.

How to deal with common laboratory accidents

1 Prevention and treatment of fire accidents

When using benzene, ethanol, ether, acetone, etc., which are volatile and flammable If handled carelessly when using organic solvents, fire accidents may occur. In order to prevent accidents, the following points must be paid attention to at all times:

(1) When operating and handling flammable and explosive solvents, keep away from fire sources; residues of explosive solids must be carefully destroyed (such as Use hydrochloric acid or nitric acid to decompose metal acetylides); do not throw away unextinguished matchsticks; do not throw away substances prone to spontaneous combustion (such as Raney nickel, the catalyst for hydrogenation reactions) and filter paper stained with them, to avoid Create a new fire source and cause a fire.

? (2) Before the experiment, you should carefully check whether the instrument installation is correct, secure and tight; the operation requirements are correct and strict; when operating at normal pressure, do not cause the system to be sealed, otherwise an explosion accident may occur; for liquids with a boiling point below 80°C , Generally, water bath heating should be used during distillation, and direct heating by fire should not be used; during experimental operations, organic vapors should be prevented from leaking out, let alone heating with open devices. Solvent removal must be done in a fume hood. ? (3) The storage of large amounts of flammable materials is not allowed in the laboratory. If a fire occurs during an experiment, do not panic and remain calm. First, immediately cut off all sources of fire and power in the room. Then rescue and extinguish the fire correctly according to the specific situation.

Commonly used methods are:?

1. When flammable liquids are burning, all flammable materials in the fire area should be removed immediately and the ventilators should be closed to prevent the expansion of combustion. ?2. When alcohol and other water-soluble liquids catch fire, use water to extinguish the fire. ?3. When organic solvents such as gasoline, ether, toluene catch fire, asbestos cloth or dry sand should be used to extinguish it. Never use water, otherwise it will expand the burning area. ?4. When metal potassium, sodium or lithium catches fire, you must not use: water, foam fire extinguishers, carbon dioxide, carbon tetrachloride, etc. to extinguish the fire. You can use dry sand and graphite powder to extinguish the fire. ?5. Note that when electrical equipment wires are on fire, do not use water or carbon dioxide fire extinguishers (foam fire extinguishers) to avoid electric shock. The power supply should be cut off first, and then use a carbon dioxide or carbon tetrachloride fire extinguisher to extinguish the fire. ?6. When your clothes are on fire, do not run. You should immediately cover them with asbestos cloth or a thick coat, or take off your clothes quickly. If the fire is large, you should lie down and roll on the ground to extinguish the flames. ?7. When you find that there is a peculiar smell or smoke coming from the oven, you should quickly cut off the power supply, let it cool down slowly, and have a fire extinguisher ready for backup. Never open the oven door in a hurry to avoid the sudden supply of air to support combustion (explosion) and cause a fire. ?8. Pay attention to protecting the scene in case of fire. Larger fire accidents should be reported to the police immediately. If anyone is seriously injured, they should be sent to the hospital immediately. ?9. Be familiar with the location of fire extinguishing equipment in the laboratory and how to use fire extinguishers.

When a fire breaks out, three things should be done: 1. Be able to call the fire alarm; 2. Be able to use fire-fighting facilities to put out the first fire; 3. Be able to save yourself and escape. ?

How to use a portable dry powder fire extinguisher:

① First tear off the small lead block and pull out the safety pin; ② Then press the handle with one hand and lift the fire extinguisher; ③ Another Hold the nozzle with one hand and spray the dry powder jet towards the root of the flame in the combustion zone. ?

2 Prevention and treatment of explosion accidents

(1) Certain compounds are prone to explosion.

For example: peroxides in organic compounds, aromatic polynitro compounds and nitrates, dry diazonium salts, azides, heavy metal acetylides, etc., are all explosive items. Special care should be taken during use and operation. There is a risk of explosion when ether containing peroxide is distilled, and the peroxide must be removed beforehand. If there is peroxide, add an acidic solution of ferrous sulfate to remove it. Aromatic polynitro compounds should not be dried in an oven. Mixing ethanol and concentrated nitric acid can cause an extremely powerful explosion. ?

(2) Incorrect instrument installation or incorrect operation may sometimes cause an explosion.

If distillation or heating and reflux are performed under normal pressure, the instrument must be connected to the atmosphere. When distilling, be careful not to evaporate the material to dryness. During decompression operations, glass instruments that are not resistant to external pressure (such as flat-bottomed flasks and Erlenmeyer flasks, etc.) cannot be used.

(3) When hydrogen, acetylene, ethylene oxide and other gases are mixed with air to a certain proportion, an explosive mixture will be generated, which will explode when exposed to an open flame. Therefore, open flames must be strictly prohibited when using the above substances. ?For synthesis reactions that generate a large amount of heat, be careful to add materials slowly and dropwise, and pay attention to cooling. At the same time, accidents caused by leakage of the piston of the dropping funnel must be prevented.

3 Prevention and treatment of poisoning accidents

Many reagents in experiments are toxic. Toxic substances often cause poisoning through inhalation, skin penetration, accidental ingestion, etc.

When dealing with irritating, odorous and toxic chemicals, such as H2S, NO2, Cl2, Br2, CO, SO2, SO3, HCl, HF, concentrated nitric acid, fuming sulfuric acid, concentrated hydrochloric acid, ethanol Acid chloride, etc. must be carried out in a fume hood. After the fume hood is opened, do not put your head into the fume hood and keep the laboratory well ventilated. During experiments, direct contact with chemicals with hands should be avoided, and direct contact with highly toxic drugs is strictly prohibited.

Organic matter stuck on the skin should be washed away immediately with plenty of water and soap. Do not use organic solvents to wash, otherwise it will only increase the speed of chemicals penetrating into the skin. Organic matter spilled on the table or floor should be removed promptly. If the mercury thermometer is accidentally damaged, the mercury scattered on the ground should be collected as much as possible and covered with sulfur powder. The highly toxic substances used in the experiments are kept by the technical leaders of each research group, distributed to users in appropriate amounts, and the remainder must be recycled. Vessels containing toxic substances in experiments must be labeled and marked, and they should be cleaned promptly after use. The workbench and sink where toxic substances are frequently used in experiments must be clearly marked. Toxic residues after experiments must be disposed of in accordance with laboratory regulations and are not allowed to be thrown away. If you experience symptoms such as burning in the throat, discoloration or cyanosis of the lips, stomach cramps, nausea and vomiting, palpitations, and dizziness during experiments with toxic substances, it may be caused by poisoning. After performing the following first aid depending on the cause of poisoning, send the person to the hospital for treatment immediately without delay. (a) Poisoning by solid or liquid poison: Spit out the poisonous substance if it is still in the mouth immediately, and rinse your mouth with plenty of water. If you accidentally eat alkali, drink a lot of water first and then drink some milk. Those who accidentally eat acid should drink water first, then take Mg(OH)2 emulsion, and finally drink some milk. Do not use emetics and do not take carbonates or bicarbonates. Those who are poisoned by heavy metal salts should drink a glass of aqueous solution containing a few grams of MgSO4 and seek medical attention immediately. Do not take vomiting drugs to avoid danger or complicating the condition. People suffering from arsenic and mercury poisoning must seek medical attention urgently. (b) Persons poisoned by inhaled gas or vapor: Immediately move outdoors, unbutton collars and buttons, and breathe fresh air. People in shock should be given artificial respiration, but do not use mouth-to-mouth. Send to hospital immediately for emergency treatment.

4 Prevention and treatment of electric shock accidents in laboratories

Electric stoves, electric heating mantles, electric mixers, etc. are often used in experiments. When using electrical appliances, direct contact between the human body and the conductive parts of the electrical appliances and asbestos should be prevented The mesh metal wire is in contact with the resistance wire of the electric furnace; do not touch the electric plug with wet hands or wet objects; it is strictly forbidden to drip water and other solvents into the electric heating jacket to prevent electrical short circuits.

In order to prevent electric shock, the metal shell of the device and equipment should be connected to the ground wire. After the experiment, the switch of the instrument should be turned off first, and then the plug connected to the power supply should be unplugged. You should use a test pen to check whether electrical equipment has leakage. Any equipment with leakage must not be used.

First aid methods in case of electric shock:?

① Turn off the power. ② Use a dry wooden stick to separate the wire from the victim. ③ Separate the victim from the ground. During first aid, first aid providers must take safety measures to prevent electric shock, and their hands or feet must be insulated. If necessary, perform artificial respiration and send to hospital for treatment.

5 First aid knowledge for other laboratory accidents

(1) For minor injuries caused by glass cuts, the dirty blood should be squeezed out in time, and the glass fragments should be removed with sterilized tweezers and rinsed with distilled water. Wash the wound, apply iodine, and then wrap it with a band-aid or bandage. For large wounds, the upper part of the wound should be tied tightly with a bandage immediately to stop bleeding, and the wound should be sent to the hospital immediately.

(2) Burns If you are burned by flame, steam, red-hot glass, iron, etc., you should immediately rinse or soak the wound with plenty of water to cool down quickly to avoid temperature burns. If blisters appear, it is not advisable to pop them. They should be bandaged with gauze and sent to the hospital for treatment. For minor burns, apply some cod liver oil or burn ointment or ten thousand flower oil on the injured area and then bandage it. If the skin blisters (second-degree burns), do not burst the blisters to prevent infection; if the skin of the injured area is brown or black (third-degree burns), lightly wrap it with dry and sterile sterile gauze and send it to the hospital for treatment.

(3) Burned by acid, alkali or bromine solution

(a) If the skin is burned by acid, rinse it immediately with plenty of running water (do not use water first when the skin is contaminated by concentrated sulfuric acid) Rinse to avoid aggravating the injury due to the strong heat generated when sulfuric acid hydrates. You should first absorb the concentrated sulfuric acid with a dry rag, and then rinse with clean water). After thorough rinse, neutralize with 2 to 5% sodium bicarbonate solution or soapy water. Finally rinse with water and apply petroleum jelly. ?(b) Alkaline burns should be rinsed immediately with large amounts of running water, then further rinsed with 2% acetic acid or 3% boric acid solution, finally rinsed with water, and then coated with Vaseline. ?(c) When phenol is burned, immediately wipe it with 30% alcohol several times, rinse it with plenty of water, and then apply it to a saturated solution of sodium sulfate for 4 to 6 hours. Because phenol is diluted with water at a concentration of 1:1 or 2:1, It can instantly aggravate skin damage and increase phenol absorption, so do not wash the contaminated surface with water first. If blisters form on the wound surface after suffering the above burns, it is not advisable to pop the blisters. The seriously injured were rushed to the infirmary after preliminary treatment.

(4) Acid, alkali or other foreign matter splashes into the eyes

(a) If acid splashes into the eyes, rinse immediately with plenty of water, then use 1% sodium bicarbonate Solution rinse. (b) If it is alkaline solution, rinse immediately with plenty of water, then rinse with 1% boric acid solution. Keep your eyelids open when washing your eyes. You can ask someone to help you open your eyelids and continue rinsing for 15 minutes. The seriously injured were immediately sent to the hospital for treatment after initial treatment. (c) If there are foreign bodies such as sawdust or dust particles, someone can open the eyelids and gently remove the foreign body with a sterilized cotton swab, or let the patient shed tears. After the foreign body is discharged, a few drops of cod liver oil can be added. It is more dangerous if glass fragments enter the eyes. At this time, try to stay calm, never rub it with your hands, and don't let others roll their eyelids. Try not to move your eyeballs, but let them shed tears. Sometimes debris will flow out with the tears. After gently covering the eyes with gauze, immediately send the injured person to the hospital for treatment.

(5) For strongly acidic corrosive poisons

Drink a lot of water first, and then take aluminum hydroxide paste and egg white; for strongly alkaline poisons, it is best to drink a lot of water first of water, then take vinegar, verjuice, and egg whites. Regardless of acid or alkalosis, you need to infuse milk and do not take vomiting agents.

(6) Mercury easily enters the human body through the respiratory tract, and can also be directly absorbed through the skin, causing cumulative poisoning.

Signs of severe poisoning include a metallic smell in the mouth and the smell of exhaled air; salivation, black mercury sulfide on the gums and lips; and swollen lymph glands and salivary glands. If you are accidentally poisoned, you should be sent to the hospital for emergency treatment. In acute poisoning, gastric lavage is usually performed thoroughly with toner or vomiting agent, or protein (such as 1 liter of milk plus 3 egg whites) or castor oil is detoxified and caused to vomit. The answer comes from