This classification not only considers practicality, but also takes into account the characteristic properties of the reagents. Therefore, it is both convenient for safe storage and easy for laboratory workers to follow safe operating rules when using it.

1. Classification of hazardous reagents
According to the properties and storage requirements of hazardous reagents, they are further divided into:
(1) Flammable reagents
This type of reagent refers to chemical substances that can spontaneously ignite or easily ignite when exposed to other substances in the air. Due to different states or causes of combustion, it can often be divided into:
① Flammable reagents: such as yellow phosphorus.
② Water burning reagents: such as potassium, sodium, calcium carbide, etc.
③ Flammable liquid reagents: such as benzene, gasoline, ether, etc.
④ Flammable solid reagents such as sulfur, red phosphorus, aluminum powder, etc.

(2) Explosive reagents
A chemical substance that undergoes a violent chemical reaction under external force, causing combustion and explosion while releasing a large amount of harmful gases. Such as potassium chlorate, etc.

(3) Toxic reagents
Refers to chemical substances that are highly toxic to humans, organisms, and the environment. Such as bromine, methanol, mercury, arsenic trioxide, etc.

(4) Oxidizing reagent
Refers to substances that can oxidize other substances and reduce themselves, such as sodium peroxide, potassium permanganate, ammonium dichromate, ammonium nitrate, etc.

(5) Corrosive reagents
Chemical substances with strong corrosiveness that can cause damage to the human body and other objects due to corrosive effects, even leading to combustion, explosion, or injury, such as strong acids, strong bases, anhydrous aluminum chloride, formaldehyde, phenol, hydrogen peroxide, etc.

2. Classification of non hazardous reagents
The properties and storage requirements of non hazardous reagents can be divided into:
(1) Reagents that are prone to spoilage when exposed to light
Refers to substances that are easily affected by ultraviolet light, which can cause the decomposition and deterioration of the reagent itself, or promote chemical changes between the reagent and the components in the air. Such as nitric acid, silver nitrate, ammonium sulfide, ferrous sulfate, etc.

(2) Reagents that are prone to spoilage when exposed to heat
These types of reagents are mostly biological products and unstable substances that can decompose, mold, and ferment at high temperatures, and some at room temperature as well. Such as ammonium nitrate, ammonium bicarbonate, agar, etc.

(3) Easy to freeze reagents
The melting point or freezing point of these reagents are within the range of temperature changes. When the temperature is higher than their melting point or falls below their freezing point, the reagents undergo volume expansion or contraction due to melting or solidification, which can easily cause the reagent bottle to explode. Such as aqueous solutions of acetic acid, crystalline sodium sulfate, crystalline sodium iodate, and bromine

(4) Easily weathered reagent
This type of reagent itself contains a certain proportion of crystal water, usually in the form of crystals. At room temperature, in dry air (usually with a relative humidity below 70%), some or all of the crystal water can gradually be lost and some can turn into powder. It is difficult to control its content during use. Such as crystalline sodium carbonate, crystalline aluminum sulfate, crystalline magnesium sulfate, alum, alum, etc.

(5) Deliquescence reagent
This type of reagent is prone to absorbing moisture from the air, causing deliquescence, deterioration, changes in appearance, decreased content, and even mold growth. Such as ferric chloride, anhydrous sodium acetate, methyl orange, agar, reduced iron powder, aluminum silver powder, etc.