Tips: What safety precautions should be taken in the laboratory?

Chemical reagents are always full of danger during the experiment, so special attention is needed!

Chemical experiments will often use various chemicals and equipment, as well as water, electricity, and gas, and will often encounter high temperature, low temperature, high pressure, vacuum, high voltage, high frequency, and experimental conditions and instruments with radiation sources. Without the necessary knowledge of safety protection, it will cause a huge loss of life and property. Therefore, it is very important for the safety protection education of the staff working in the chemical laboratory. All staff must pay attention to it.

Hazardous Chemicals

1, flammable reagents

When dealing with flammable reagents, it should be strictly checked whether there is any open flame in the vicinity. The following commonly used organic solvents are very flammable:

Hydrocarbons such as hexane, light petroleum (ie, petroleum ether), benzene, toluene; alcohols such as methanol, ethanol; esters such as ethyl acetate; ketones such as acetone; ethers due to their exposure to air or light Produce explosive peroxides. Therefore, use special care. Commonly used ethers and tetrahydrofuran are ethers, and care must be taken when handling them.

In addition, ether also has a relatively low boiling point and a certain degree of anesthetic effect. Carbon disulfide has a high flammability. Even heating with a water bath will cause it to catch fire. Therefore, it should be avoided in experiments.

2, oxidants

Sulfuric acid and nitric acid are both highly corrosive and strongly oxidizing. Like bleach, hydrogen peroxide, peracid, cobalt dioxide and potassium permanganate are all very strong oxidants.

3, corrosive drugs

Always wear protective gloves when handling or using corrosive reagents. Once splashed on skin, rinse immediately with plenty of water. Sulfuric acid, hydrochloric acid, hydrobromic acid, phosphoric acid and nitric acid in inorganic acids, carboxylic acids and sulfonic acids in organic acids are all corrosive. Phenol is also very dangerous and can cause skin burns. Its toxic vapors can be absorbed by the skin. Strong bases such as sodium hydroxide and potassium hydroxide in inorganic bases, and weak bases such as sodium sulfate and potassium sulfate are corrosive, and amines, hydroxylamine, triethylamine, and pyridine in organic bases are corrosive.

Liquid bromine is a very dangerous drug. It can cause skin and eye burns, so be sure to use it in a fume hood. In addition, due to its high density, when transferring with a dropper, even if the latex head is not squeezed, it may drop due to its gravity. Therefore, special care must be taken when using it.

Thionyl chloride, acid chloride, anhydrous aluminum trichloride, and other reagents, which react with water to release hydrogen chloride gas, are also corrosive and can cause serious irritation to the respiratory system.

Safety knowledge

1, eye protection

Wear goggles or goggles on the outside of regular glasses and do not wear contact lenses in the lab. If there is a splash of medicine in your eyes, take urgent care.

2, wearing, clothing

Wear chemical protective clothing in the laboratory. In addition, do not wear slippers or sandals.

3, instruments and equipment

In general, do not try to use an instrument or device without knowing its function. Like vacuum absorption pumps, rotary evaporators, compressed gas cylinders, etc., misuse can result in damage to these expensive instruments, or failure of the experiment, and more serious cause some accidents. Before installing the laboratory equipment, inspect the glass ground for debris or debris. Before adding a drug reaction, be sure to check that all instruments used are clamped, fixed, and installed.

4, drug treatment

Chemicals are dangerous because they are toxic, corrosive, and flammable. In the organic chemistry laboratory, the best condition is not to use an open flame. To heat the reaction mixture or the solvent, it is preferable to use a water bath, an oil bath, an electric furnace or an electric heating jacket. If you need to use a gas light, be sure to check that there are no flammable liquids around. Similarly, when transferring or dumping flammable liquids, check that there are no open flames around. The vapor pressure of organic solvents is generally greater than air, so do not pour liquids, especially flammable solvents, into sewers or drains.

5, harmful and toxic reagents

Many of the compounds normally seen are toxic and must therefore be used in fume hoods such as benzene, bromine, dimethylsulphate, chloroform, hexane, methyl iodide, mercury salts, methanol, nitrobenzene, phenol, Cyanide A, sodium chloride and so on. Try to avoid long-term contact. Always use it in a fume hood. It is best to wear a gas mask to improve safety.