Safe Use Of Chemical Reagents

1. Flammable and explosive chemical reagents

Generally, chemical reagents with a flash point below 25°C are listed as flammable chemical reagents. Most of them are extremely volatile liquids and can burn when exposed to an open flame. The lower the flash point, the easier it is to burn. Common flash points below -4°C include petroleum oil, ethyl chloride, ethane condensate, ether, gasoline, carbon dioxide, propane, benzene, ethyl acetate, and methyl acetate.

Never use open flame when using Ene chemical reagents. It can’t be heated directly with a heater. Generally, it is not heated in a water bath. Such chemical reagents should be stored in a cool and well-ventilated place. For accidents that burn down the entire laboratory, in places where a large number of such chemical reagents are used, good ventilation must be maintained at once, explosion-proof electrical appliances must be used, and there must be no open flames on site.

Flammable reagents can also explode when burned fiercely. Some solid chemical reagents such as nitrocellulose, picric acid, trinitrotoluene, trinitrobenzene, azide or overlapping compounds, hormonate, etc., are themselves explosive. When exposed to heat or open flames, they are very easy to burn or decompose and explode. When using these chemical reagents, they must not be directly heated. When using these chemical reagents, be careful not to have open flames around.

There is also a class of solid chemical reagents, which can react violently when exposed to water, emit a lot of heat, and can also explode. Such chemical reagents include metallic potassium, sodium, lithium, calcium, aluminum hydride, calcium carbide and so on. When using these chemical reagents, you must avoid direct contact with water.

Some solid chemical reagents can oxidize strongly when they come into contact with them. Such as yellow phosphorus; some contact with oxidants or heat, impact or friction in the air can cause rapid combustion or even explosion. Such as phosphorous sulfide, red phosphorous magnesium powder, zinc powder, aluminum powder, puree, smashing brain, etc., when using these chemical reagents, be sure to pay attention to the ambient temperature not too high (generally not more than 30 ℃, preferably at 20 ℃ Below) Do not contact with strong oxidants.

Experimenters who use flammable chemical reagents should wear necessary protective equipment, preferably protective glasses.

2. Toxic chemical reagents

General chemical reagents are poisonous to the human body, so you must avoid large amounts of inhalation when using them. After using the performance reagents, wash your hands, face, bath, and change your overalls. For some inhalation or ingestion of a small amount, it can be poisoned to death. Chemical reagents. Those with a dead weight (LD50) below 50mg/kg in biological tests are called highly toxic chemical reagents, such as potassium cyanide, sodium cyanide and other cyanides, arsenic trioxide and certain arsenic compounds, mercury dichloride And some mercury salts, sulfuric acid, dimethyl ester and so on. When using unclear chemical reagents, you must understand its LD50. For some commonly used highly toxic chemical reagents, it is necessary to understand the emergency treatment methods when these chemical reagents are poisoned, and the highly toxic chemical reagents must be kept by special personnel, and the amount of use must be strictly controlled.

3. Corrosive chemical reagents

Any chemical reagents should be cleaned in time when they touch the skin, mucous membranes, eyes, and respiratory organs, especially those that are extremely corrosive to the skin, mucous membranes, eyes, and respiratory organs (whether liquid or solid), such as: various Acids and bases, phosphorus trichloride, phosphorus oxychloride, bromine, phenol, hydrazine, etc. It is also necessary to avoid touching the skin, mucous membranes, eyes, and respiratory organs. Before use, be sure to understand the emergency treatment methods for contact with these corrosive chemical reagents. If acid splashes on the skin, wash it with dilute lye and so on.

4. Strong oxidizing chemical reagent

Strong oxidizing chemical reagents are all peroxides or oxyacids and their salts with strong oxidizing power. Such as: peroxidic acid, ammonium nitrate, potassium nitrate, perchloric acid and its salts, bicomplex acid and its salts, permanganic acid and its salts, peroxybenzoic acid, peracetic acid, phosphorus pentoxide and so on. Strong oxidizing chemical reagents can release oxygen and explode under appropriate conditions, and form explosive mixtures with organic matter such as magnesium, aluminum, zinc powder, sulfur and other combustibles. Some water may also explode. When using such strong oxidizing chemicals When reagents are used, the ambient temperature should not be higher than 30°C, the ventilation should be good, and it should not be used together (heated) with organic or reducing substances.

5. Radiochemical reagent

When using this type of chemical reagent, you must take protective measures in accordance with the method of using radioactive materials.