What is dangerous goods transportation?

Dangerous goods are a general term for flammable, explosive, and strongly corrosive materials. The transportation of dangerous goods poses great risks, and a slight lack of attention may cause material loss or personal injury. According to different properties, dangerous goods are divided into the following types.

According to the two national standards of Classification and Marking of Common Hazardous Chemicals (GB13690-2009) and Classification and Name Number of Dangerous Goods (GB6944-2005), chemicals are divided into 8 categories according to their risks: ① explosives ② compressed gases and liquefied gases ③ Flammable liquid ④ flammable solids, self combustible substances and flammable substances in wet conditions ⑤ oxidants and Organic peroxides ⑥ toxic and infectious substances ⑦ radioactive substances ⑧ corrosives.

Class 1 Explosives

This type of chemical refers to materials that can undergo intense chemical reactions under external influences (such as heat, pressure, impact, etc.), instantly generating a large amount of gas and heat, causing a sudden increase in surrounding pressure, causing explosions, and causing damage to the surrounding environment. It also includes pyrotechnic materials that have no overall explosion risk but have combustion, projection, and minor explosion risks, or only produce one or several effects such as heat, light, sound, or smoke.

Explosive is the main characteristic of all explosives

These types of items are chemically unstable and undergo violent chemical reactions under certain external factors, with the following four main characteristics:

·The rate of chemical reaction is extremely fast. Chemical reactions are usually completed in one thousandth of a time, as the explosive energy is released in an extremely short period of time and therefore has enormous destructive power.

·A large amount of heat is generated during an explosion. This is the main source of explosives.

·Generate a large amount of gas, causing high pressure. The shock waves formed have great destructive effects on surrounding buildings.

Very sensitive to impact, friction, temperature, etc

The explosion of any type of explosive requires a certain amount of energy from the outside - initiating energy. The minimum initiation energy required for a certain explosive is the sensitivity of that explosive. Sensitivity is a very important indicator for determining the explosion risk of explosives, and the higher the sensitivity, the greater the explosion risk.

Some explosives also have a certain degree of toxicity

For example, TNT, nitroglycerin, mercuric acid, etc. all have certain toxicity.

React with acids, bases, salts, and metals

Some explosives undergo chemical reactions with certain chemicals such as acids, bases, and salts, resulting in more explosive chemicals. For example, Picric acid can react with some carbonates to form more explosive Picric acid salt; Picric acid was impacted by copper, iron and other metals, and immediately exploded.

Class 2 compressed gases and liquefied gases

This category of chemicals refers to gases that are compressed, liquefied, or dissolved under pressure, and should meet one of the following two conditions:

Compressed or liquefied gas whose critical temperature is lower than 50 ℃, or whose vapor pressure is greater than 294KPa at 50 ℃;

Compressed gas with an absolute pressure greater than 275KPa at 21.1 ℃ or 715KPa at 54.4 ℃; Or liquefied gas or pressurized dissolved gas with Reid Vapor pressure greater than 275KPa at 37.8 ℃.

The first flammable gas

This type of gas is highly flammable and can form explosive mixtures when mixed with air. Under normal temperature and pressure, combustion or explosion can occur when exposed to open flames or high temperatures. Or poisoning

All compressed gases are hazardous because they are under high pressure. Some gases have properties such as flammability, explosiveness, combustion support, and high toxicity, which can easily cause combustion, explosion, or poisoning accidents under heating, impact, and other conditions.

Item 2 Non combustible gas

Non combustible gas system refers to non-toxic and non combustible gases, including combustion supporting gases. But at high concentrations, it has a suffocating effect. Combustion gases have a strong oxidizing effect and can cause combustion or explosion when encountering grease.

Item 3 Toxic Gas

This type of gas is toxic, and its toxicity index is the same as that of Category 6. It has a strong toxic, suffocating, burning, and irritating effect on humans and animals. Some of them also have properties such as flammability, oxidation, corrosion, etc.

Class 3 Flammable liquid

This category of chemicals refers to flammable liquids, liquid mixtures, or liquids containing solid substances, but does not include liquids that have been classified into other categories due to their hazardous nature. Its closed cup flash point is equal to or lower than 61 ℃.

According to the high and low flash points, it can be divided into the following three items:

Item 1 Low flash point liquid

Refers to liquids with a closed cup flash point below -18 ℃;

Flash point liquid in item 2

Refers to a liquid with a closed cup flash point between -18 ℃ and 23 ℃;

Item 3 High flash point liquid

Refers to a liquid with a closed cup flash point between 23 ℃ and 61 ℃.

Flammable liquid has the following characteristics:

Highly flammable

The main characteristic of Flammable liquid is that it is highly flammable, and there is a risk of combustion in case of fire, heating and contact with oxidant. The magnitude of its danger is related to the flash point and spontaneous ignition point of the liquid. The lower the flash point and spontaneous ignition point, the greater the risk of ignition and combustion.

Explosivity

Because of the low boiling point of Flammable liquid, the concentration of the volatilized steam mixed with air is easy to reach the Flammability limit, and it often explodes when encountering the fire source.

Highly fluid diffusive

The viscosity of Flammable liquid is generally very small. It is not only easy to flow itself, but also because of infiltration, infiltration and Capillary action. Even if the container has only tiny cracks, Flammable liquid will also leak out of the container wall. After leakage, it is easy to evaporate, forming flammable vapor that is heavier than air and can accumulate in potholes, thereby increasing the risk of combustion and explosion.

Easy to accumulate charge

Some Flammable liquid, such as benzene, toluene, gasoline, etc., have high resistivity, which is easy to accumulate static electricity and generate static sparks, causing fire accidents.

Thermal expansion

The expansion coefficient of Flammable liquid is relatively large, and its volume is easy to expand after being heated. At the same time, its Vapor pressure also increases, so that the internal pressure in the sealed container increases, resulting in "drum" or even burst. When the container bursts, sparks will be generated, causing combustion and explosion. Therefore, Flammable liquid should be stored away from heat; When filling, there should be a gap of more than 5% inside the container.

toxicity

Most Flammable liquid and their vapors have varying degrees of toxicity. Therefore, labor protection work should be done well during the operation process.

Flammability is the main characteristic of Flammable liquid. Special attention shall be paid to:

Smoking and fire are strictly prohibited, and keep away from ignition and heat sources;

It is prohibited to use iron tools that are prone to sparks and wear shoes with iron nails;

Category 4 Flammable Solids, Spontaneous Combustion Materials, and Flammable Materials in Contact with Moisture

Item 1: Flammable Solids This chemical refers to solids with low ignition points, sensitive to heat, impact, and friction, easily ignited by external ignition sources, rapidly burning, and potentially emitting toxic smoke or gases, but does not include substances that have been classified as explosives.

(1) The main characteristic of flammable solids is their susceptibility to oxidation, decomposition or sublimation when heated, and strong and continuous combustion when exposed to open flames.

(2) In contact with oxidants, acids, etc., the reaction is intense and leads to combustion and explosion.

(3) It is also sensitive to friction, impact, and vibration.

(4) Many flammable solids are toxic, or combustion products are toxic or corrosive.

For flammable solids, special attention should be paid to dust explosions!

Item 2: Spontaneous combustion items

This chemical refers to items that have a low spontaneous ignition point and are prone to oxidation reactions in the air, releasing heat and self burning.

Flammability is the main characteristic of self igniting materials

Spontaneous combustion materials have irregular chemical structures, so they have different characteristics of spontaneous combustion:

(1) Yellow phosphorus has active properties, is highly oxidizable, and has a particularly low ignition point. Once exposed to air, it quickly causes spontaneous combustion. But yellow phosphorus does not react chemically with water, so it is usually stored in water. In addition, yellow phosphorus is extremely toxic, and its combustion product Phosphorus pentoxide is also toxic, which can generate highly toxic metaphosphoric acid when encountering water. So when encountering phosphorus burning, attention should be paid to preventing poisoning during the firefighting process.

2) Organic metal compounds such as Diethylzinc and Triethylaluminium can not only spontaneously ignite in air, but also decompose strongly when encountering water, producing flammable hydrogen, causing combustion and explosion. Therefore, storage and transportation must be packaged with inert gas or specific containers, and water cannot be used to extinguish fires.

Take corresponding measures based on the different characteristics of spontaneous combustion items!

Item 3: Flammable items when wet

This chemical refers to items that undergo intense chemical reactions when exposed to water or moisture, releasing a large amount of flammable gases and heat. Some items can burn or explode without the need for an open flame.

In addition to reacting with water, flammable substances that come into contact with moisture can also react with acids or oxidants, and the reaction is stronger and more dangerous than the reaction that comes into contact with water. Therefore, during storage, transportation, and use, attention should be paid to waterproof and moisture-proof measures. It is strictly prohibited to approach sparks, and substances that conflict with other properties should be isolated and stored.

In case of fire caused by wet flammable substances, it is strictly prohibited to use water, acid alkali foam and chemical foam to put out the fire!

Class 5 oxidants and Organic peroxides

1st oxidant

Oxidant refers to a substance that is in a high Oxidation state, has strong oxidizability, is easy to decompose, and emits oxygen and heat. Including organic compounds containing peroxide groups, which may not necessarily be flammable themselves, but can lead to the combustion of combustible materials; It can form explosive mixtures with soft powdered combustible materials and is sensitive to heat, vibration, or friction.

Oxidants have a strong ability to acquire electrons and have strong oxidizing properties. They can quickly decompose when exposed to acids, alkalis, high temperatures, vibrations, friction, impacts, dampness, or in contact with flammable substances, reducing agents, etc., posing a risk of combustion and explosion.

Item 2 Organic peroxides

Organic peroxides refer to organic substances containing peroxy groups in their molecular composition, which are flammable, explosive, easily decomposed, and extremely sensitive to heat, vibration and friction.

Category 6 toxic and infectious substances

Item 1 Toxic Substances

Specific indicators: LD50 ≤ 500 mg/kg (solid)

LD50 ≤ 2000 mg/kg (liquid)

Transcutaneous: LD50 ≤ 1000 mg/kg (24 hr contact)

Inhalation: LC50 ≤ 10 mg/L (dust, smoke, vapor)

Item 2 Infectious Substances

This chemical refers to substances containing pathogenic microorganisms that can cause illness or even death.

Class 7 radioactive materials

This type of chemical refers to a radioactive specific activity greater than 7.4 × Items of 10Bq/kg.

Radioactive

The radiation emitted by radioactive substances can be divided into four types: α X-rays, also known as alpha rays; β X-rays, also known as B-rays; γ X-rays, also known as gamma rays; There is also a neutron flow. All kinds of radiation pose great harm to the human body.

Many radioactive substances are highly toxic

Chemical methods cannot be used to neutralize it and prevent it from emitting radiation. Instead, efforts can be made to remove radioactive substances or absorb and shield them with appropriate materials.

Category 8 corrosive products

This category of chemicals refers to solids or liquids that can burn human tissues and cause damage to metals and other items. Within 4 hours of contact with the skin, visible necrosis occurs, or at a temperature of 55 ℃, solid or liquid with a uniform annual corrosion exceeding 6.25 mm on the surface of No. 20 steel. This type of chemical is divided into three categories based on its chemical properties:

Item 1: Acid corrosive products

Item 2 Alkaline corrosion products

Item 3 Other corrosive products

Strong corrosiveness

Among chemical hazardous materials, corrosive substances are substances with relatively active chemical properties that can react with many metals, organic compounds, animal and plant organisms, etc. These substances can burn human tissues and have a strong corrosive effect on metals, animal and plant organisms, fiber products, etc.

Most corrosive products have varying degrees of toxicity, and some are still highly toxic.

Flammability

Many organic corrosive substances have flammability. Such as formic acid, glacial acetic acid, Benzoyl chloride, acrylic acid, etc.

Oxidative properties

For example, nitric acid, sulfuric acid, Perchloric acid, bromine, etc., when these substances contact wood chips, sugar, gauze and other combustibles, oxidation reaction will occur, causing combustion.

Dangerous goods, as essential items for economic development, need to exist. At the same time, due to their enormous damage, they must be properly stored, strictly follow operating procedures, maintain high vigilance, strengthen monitoring, and prevent accidents from happening.

Any unit engaged in the transportation of dangerous goods on the road must have corresponding facilities and equipment that can ensure the safe transportation of dangerous goods.

Article 6: Units engaged in the transportation of dangerous goods on commercial roads must have a business scale of at least ten specialized vehicles, at least five years of management experience in transportation operations, equipped with corresponding professional technical management personnel, and have established and improved safety operation regulations, job tenure, vehicle equipment maintenance and repair, and safety and quality education regulations.

Article 7: Personnel directly engaged in the transportation, loading and unloading, maintenance operations, and business management of dangerous goods on roads must master relevant knowledge of dangerous goods transportation, pass the assessment of the local road transportation management authority at or above the city level, and be issued a "Road Dangerous Goods Transportation Operation Certificate" before they can start work.

Article 8: Vehicles, containers, loading and unloading machinery, and tools used for transporting dangerous goods must meet the conditions specified in the JT3130 "Regulations on the Transport of Dangerous Goods by Motor Vehicles" of the Ministry of Transport, and must pass the inspection by the road transportation management authority.

Article 9: Non business transportation units that need to engage in road transportation of dangerous goods must submit a written application to the local road transportation management authority in advance. After examination and approval, those that meet the basic transportation conditions of these regulations must be submitted to the local (city) level transportation management authority for approval and issued a "Road Dangerous Goods Non Business Transportation Certificate" before carrying out transportation operations. To engage in one-time road transportation of dangerous goods, it is necessary to report to the county-level transportation management authority for review and approval, and issue a "Temporary Transport Certificate for Road Dangerous Goods" before transportation operations can be carried out.

Article 10: Any unit that applies to engage in the transportation of dangerous goods on commercial roads, as well as any unit that has obtained the qualification for commercial road transportation and needs to increase the number of dangerous goods transportation business projects, must submit a written application to the local county-level road transportation management authority in accordance with regulations, which shall be reviewed by the county-level (city) road transportation management authority, Only by issuing a "Road Transport Operation License" and a "Road Transport Operation Certificate" stamped with a special seal for the transportation of dangerous goods on the road, can we operate the transportation of dangerous goods on the road.