2 Prevention and treatment of explosion accidents

(1) Certain compounds are prone to explosion.

Such as: peroxides in organic compounds, aromatic polynitro compounds and nitrates, dry diazonium salts, azides, heavy metal acetylides, etc., are explosive materials, should pay special attention to the use and operation . When the peroxide-containing ether is distilled, there is a danger of explosion, and the peroxide must be removed beforehand. If there is a peroxide, it can be removed by adding an acidic solution of ferrous sulfate. Aromatic polynitro compounds are not suitable for drying in an oven. The combination of ethanol and concentrated nitric acid can cause a very strong explosion;

(2) The instrument device is incorrect or incorrectly operated, sometimes causing an explosion.

If distillation or heating is carried out under normal pressure, the instrument must be connected to the atmosphere. Be careful when distilling, do not evaporate the material. Glass instruments that are not resistant to external pressure (such as flat-bottomed flasks and Erlenmeyer flasks, etc.) cannot be used during decompression operations.

(3) When a gas such as hydrogen, acetylene or ethylene oxide is mixed with air to a certain ratio, an explosive mixture will be formed, which will explode if exposed to an open flame. Therefore, an open flame must be strictly prohibited when using the above substances. For the synthesis reaction with a large amount of heat release, carefully add the material slowly and pay attention to the cooling, and at the same time prevent accidents caused by the leakage of the piston of the dropping funnel.

3 prevention and treatment of poisoning accidents

Many of the reagents in the experiment were toxic. Toxic substances often cause poisoning through respiratory inhalation, skin infiltration, and ingestion.

When handling irritating, malodorous and toxic chemicals, such as H2S, NO2, Cl2, Br2, CO, SO2, SO3, HCl, HF, concentrated nitric acid, fuming sulfuric acid, concentrated hydrochloric acid, acetyl chloride, etc., must be in the fume hood In progress. After the fume hood is opened, do not put your head into the cabinet and keep the laboratory well ventilated.

In the experiment, direct contact with chemicals should be avoided, especially for direct contact with drugs. Organic matter on the skin should be washed immediately with plenty of water and soap. Do not wash with organic solvents, as this will only increase the rate at which chemicals penetrate the skin.

Organic matter splashed on the table or the ground should be removed in time. If the mercury thermometer is accidentally damaged, the mercury that has fallen on the ground should be collected as much as possible and covered with sulphur powder in the place where it is scattered.

The highly toxic substances used in the experiment are kept by the technical leaders of each research group, and are distributed to the users in an appropriate amount and the remaining is to be recovered. The utensils containing the toxic substances should be labeled and marked, and should be cleaned in time. The operating tables and sinks of the toxic substances are often used. The toxic residues after the experiment must be disposed of in accordance with the laboratory regulations and are not allowed to be littered.

In the operation of toxic substances, if you feel sore throat, discoloration or cyanosis of the lips, stomach cramps or nausea and vomiting, palpitations and dizziness, it may be caused by poisoning. Immediately after the first aid, the following emergency treatment is given to the hospital for treatment, without delay.

 (a) Solid or liquid poisoning: The toxic substance is spit out immediately in the mouth and rinsed with plenty of water. If you are eating alkali, drink plenty of water and drink some milk. Those who eat acid, drink water first, then take Mg(OH)2 emulsion, and finally drink some milk. Do not use emetics or take carbonates or bicarbonates. For heavy metal salt poisoning, drink a cup of aqueous solution containing a few grams of MgSO4 and seek medical attention immediately. Do not take vomiting medicine to avoid danger or complicate the condition. People with arsenic and mercury poisoning must seek medical attention urgently.

(b) Inhaled gas or vapor poisoning: Immediately transfer to the outside, untie the collar and buttons, and breathe fresh air. Artificial shock should be applied to the shock, but do not use the mouth-to-mouth method. Immediately send the hospital first aid.

4 Prevention and treatment of electric shock accidents in laboratories

In the experiment, electric furnace, electric heating sleeve, electric mixer, etc. are often used. When using electrical appliances, the human body should be prevented from direct contact with the conductive parts of the electrical appliance and the asbestos mesh wire should be in contact with the electric resistance wire of the electric furnace; the wet hand or the hand should not be used to contact the electric plug. It is strictly forbidden to drip water and other solvents into the electric heating sleeve to prevent short circuit of the electrical equipment.

In order to prevent electric shock, the metal casing of the device and equipment should be connected to the ground wire. After the experiment, the instrument switch should be turned off, and then the plug connected to the power supply should be turned down.

Check the electrical equipment for leakage. Use a test pencil. Any leaking instrument should not be used.

First aid method when electric shock occurs:

1 turn off the power;

2 use a dry wooden stick to separate the wire from the victim;

3 Separate the victim from the land. In the first aid, the first-aider must take safety measures to prevent electric shock. The hand or foot must be insulated. If necessary, perform artificial respiration and send it to the hospital for treatment.

5 First aid knowledge of other accidents in the laboratory

(1) Glass cut: Generally, light injury should be squeezed out in time, and the glass fragments should be taken out with sterile tweezers. Wash the wound with distilled water, apply iodine, and then bandage with band-aid or bandage; large wound should be used immediately. The bandage tightened the upper part of the wound, causing the wound to stop bleeding and rushing to the hospital for treatment.

(2) Scalding: When burned by flame, steam, red hot glass, iron, etc., immediately wash or soak the wound with plenty of water to quickly cool down to avoid temperature burns. If it is blistered, it should not be broken. Apply gauze and then send it to hospital for treatment. For minor burns, apply some cod liver oil or scalding ointment or scented oil to the wound. If the skin is blistering (secondary burn), do not break the blisters to prevent infection; if the skin is brown or black (three-level burn), apply a dry and sterile sterile gauze and gently wrap it in the hospital.

(3) Burned by acid, alkali or bromine:

(a) When the skin is burnt by acid, rinse it with plenty of running water immediately. (If the skin is contaminated with concentrated sulfuric acid, avoid flushing with water first, so as to avoid the strong heat release when the sulfuric acid is hydrated, and the injury should be aggravated. You should first remove the concentrated sulfuric acid with a dry cloth, then Rinse with water), rinse thoroughly, neutralize with 2 to 5% sodium bicarbonate solution or soapy water, and finally rinse with water and apply the Vaseline.

(b) The lye burn should be washed immediately with a large amount of running water, further rinsed with 2% acetic acid or 3% boric acid solution, and finally rinsed with water, and then coated with petrolatum.

(c) Immediately wash the phenol with 30% alcohol, rinse it with plenty of water, and then apply it with a saturated solution of sodium sulfate for 4 to 6 hours. Since the phenol is diluted with water by 1:1 or 2:1, it is instantaneous. Can increase the damage of the skin and increase the absorption of phenol, so do not rinse the contaminated surface with water first. After the above burns, if the wound surface blisters, it is not appropriate to break the blisters. After serious treatment, the seriously injured person was rushed to the infirmary.

(4) Acid, lye or other foreign matter splashed into the eyes:

(a) The acid splashed into the eyes, rinsed immediately with plenty of water, and rinsed with 1% sodium bicarbonate solution.

(b) If it is an alkali solution, rinse immediately with plenty of water and rinse with 1% boric acid solution. Keep your eyelids open when you wash your eyes. You can help open the eyelids and continue to rinse for 15 minutes. Severely injured patients were sent to hospital for treatment immediately after initial treatment.

(c) If foreign matter such as wood chips or dust particles can be opened by others, gently remove the foreign matter with a sterile cotton swab, or allow it to shed tears. After the foreign matter is discharged, add a few drops of cod liver oil. It is dangerous if the glass swarf enters the eye. At this time, try to keep calm. Never rub it with your hands. Don't let others turn your eyes. Try not to turn your eyes, let them cry, and sometimes the debris will flow out with tears. After gauze, gently wrap your eyes, immediately send the injured to the hospital.

(5) For strong acid corrosion poisons, first drink a lot of water, then take aluminum hydroxide paste, chicken protein; for strong alkaline poisons, it is best to drink a lot of water, then take vinegar, sour juice, chicken protein. Do not infuse the milk with acid or alkali poisoning. Do not take vomiting agents.

(6) Mercury can easily enter the human body through the respiratory tract, and can also be directly absorbed by the skin to cause cumulative poisoning.

The signs of severe poisoning are metallic odor in the mouth, exhaled gas also smells; saliva, black on the gums and lips with mercury sulfide; swollen lymph glands and salivary glands. If you are inadvertently poisoned, you should be sent to the hospital for emergency treatment. In acute poisoning, the stomach is thoroughly washed with toner or vomiting agent, or protein (such as 1 liter of milk plus 3 egg whites) or castor oil is detoxified and vomited.