According to the commonly used the classification of dangerous chemicals and mark "(GB 13690-92), China could be divided into 8 classes of dangerous chemicals according to the danger of 21 items.

Class 1, explosives;

The second class, compressed gases and liquefied gases;

Class 3, flammable liquid.

Class 4, flammable solid, combustion and in wet flammable items;

Class 5, antioxidants and organic peroxide;

6 classes, poisoning and infectious items;

Class 7, radioactive substances;

Class 8, corrosion product.

1, explosives

Under the action of this kind of chemicals in the outside world (such as heat, the friction and impact, etc.), severe chemical reactions can occur, instantaneous produces large amounts of gas and heat, the surrounding pressure rapid rise, explosion, damage to the environment, do not include no overall explosion danger, but it is burning, smaller mass ejection and explosive dangerous goods.

The explosives is divided into five: 1. The whole explosives: material and goods with integral explosion danger;2. Mass ejection explosives: with mass ejection danger, but there is no overall explosion dangerous substances and articles;Items: 3. Burning explosion with burning danger or smaller and smaller explosion mass ejection dangerous, or both, but no overall explosion dangerous substances and articles: 4. General explosives: no major dangerous explosive material and goods, was lit one thousand or detonate, its most dangerous role inside the package, but outside of packaging are no significant danger;5. Insensitive explosives: very insensitive explosive substances, relatively stable, will not explode in the burning test.

2, compressed gases and liquefied gases

Refers to the compression, liquefied or pressurized dissolved gases, and in accordance with the following one of two things: (1) the critical temperature is lower than 50 ℃, or at 50 ℃, the vapor pressure is greater than 294 kpa compressed or liquefied gases;(2) when temperature 21.2 ℃, the absolute pressure of the gas is more than 257 kpa, or at 54.4 ℃, the absolute pressure of the gas is greater than 715 kpa compressed gas;Or 37.8 ℃, Reid vapor pressure is greater than 275 kpa of liquefied gas or pressurized dissolved gas.This item when heated, or strong shock of impact, the pressure in the container will increase sharply, causing explosion vessel rupture, loose or cause cylinder valve leakage, fire or poisoning accident.

According to its nature is divided into the following three items: (1) flammable gas;(2) non-flammable gas (including combustion-supporting gas);(3) of toxic gases.

3, flammable liquid

Refers to the closed cup flash point is equal to or lower than 61 ℃ of the liquid, the mixture of liquid or liquid containing solid material, but not including due to the danger has been included in other classes of the liquid.This kind of material volatile at room temperature, its vapor and air mixture can form explosive mixture.

According to the flash point is divided into the following three items: (1) low flash point liquid flash point < - 18 ℃;(2) in the flash point of liquid - 17 ℃ or less flash point < 23 ℃;(3) high flash point liquid 23 ℃ or less flash point 61 ℃ or less.

4, inflammable solid, combustion and in wet flammable items This item is easy to cause and contribute to a fire,

According to its combustion characteristic is divided into the following three items: (1) flammable solid: refers to the low ignition point, sensitivity to heat, impact, friction, vulnerable to external fire ignited, burning rapidly, and may emit toxic fumes or toxic gas solid;(2) the spontaneous combustion items: refers to the self-ignition point is low, easy to occur in the air oxidation reaction, gives off heat, and the burning items on its own;(3) meet wet flammable items: refers to the water, or be affected with damp be affected with damp, intense chemical reaction occurs, release a large number of flammable gas and heat.Some don't need to open that can burn or explosion.

5, oxidant and organic peroxides

This item has a strong oxidizing, easy cause burning and explosion,

According to its composition is divided into the following two items: (1) the oxidant At a high oxidation state, has the strong oxidizing, easy to decompose and release oxygen and heat of the material.Contains a base of inorganic peroxide, its itself is not necessarily flammable, but it can lead to burning of fuel;With powdered fuel can form explosive mixture, sensitive to heat, vibration or friction.According to its size, risk is divided into primary antioxidants and secondary antioxidant.(2) organic peroxides refers to molecules contain key organic peroxide, its itself flammable and explosive, easy to decompose, extremely sensitive to heat, vibration and friction.

6 items, poisoning and infectious

Refers to the after entering the body, has reached a certain amount, can with body fluids and tissues in biological chemistry or physics, disrupt or destroy the body's normal physiological function, cause temporary or persistent pathological change, dangerous and even life.Specific indicators through the mouth: LD50 500 mg/kg or less (solid) LD50 2000 mg/kg or less (liquid) percutaneous contact (24 h) : LD50 1000 mg/kg or less (solid) inhalation LC50 10 mg/L) (dust, smoke or less

The class divided into poison, infectious items 2 items.The poison product as its toxicity is divided into primary and secondary poisoning.

A lot of subentry method 7, radioactive substances, the comparison of several commonly used have the following.

1. The physical form separately

: (1) solid radioactive items such as cobalt 60, monazite, etc;

(2) powder radioactive substances, such as cerium noctilucent powder, sodium double salts, etc.;

(3) the liquid radioactive substances, such as FaGuangJi, medical isotopes preparation sodium dihydrogen phosphate - P32, etc.

(4) the grain shape of radioactive substances, such as thorium nitrate, etc.

(5) gas radioactive items: such as krypton 85 argon 41.

2. According to the release of radiation type component

(1) release of alpha, beta, gamma rays, radioactive substances, such as radium 226;

(2) the release of alpha, beta, radioactive substances;Such as the natural uranium;

(3) release beta, gamma rays, radioactive substances, such as cobalt 60;

(4) released neutron flow (also released alpha, beta, and gamma rays in one or two) of radioactive substances:

Such as radium - streams of beryllium, polonium - beryllium flow, etc.

3. According to the size of radioactive level radioactive substances, secondary radioactive substances, radioactive substances.

8, corrosion product

Refers to the corrosion product can burn the body's tissues and cause damage to metal items such as the solid or liquid.Contact with the skin necrosis occurs in 4 hours, or the temperature in 55 ℃, even in the performance of 20 steel corrosion rate is more than 6.25 mm/a solid or liquid.

The class according to the chemical properties are divided into three items: (1) the acid corrosion;(2) the alkaline corrosion;(3) other corrosion product.According to its strong and weak corrosive is subdivided into the corrosion product and secondary corrosion products.