Flammable liquids can be said to be ubiquitous in our lives. Whether it is gasoline, industrial toluene, consumer products such as perfumes and cosmetics, or even high-proof liquor, all fall under the category of flammable liquids. It can be said that flammable liquids are one of the most common types of hazardous chemicals in our production and daily lives. This article explores the hazard classification of flammable liquids from the perspective of GHS classification.
Under the GHS system, flammable liquids refer to liquids with a flash point not exceeding 93°C, and they are divided into four categories based on the flash point and initial boiling point data of the liquids. The specific classifications are as follows:
Category |
Classification Basis |
Category 1 |
Flash point <23°C, and initial boiling point ≤35°C |
Category 2 |
Flash point <23°C, and initial boiling point >35°C |
Category 3 |
Flash point ≥23°C and ≤60°C |
Category 4 |
Flash point >60°C and ≤93°C |
Compared to the classification of flammable liquids in the United Nations Model Regulations on the Transport of Dangerous Goods (UN TDG), the scope of flammable liquids under the GHS system is broader. Under UN TDG, only liquids with a flash point not exceeding 60°C are defined as flammable liquids. Liquids with a flash point greater than 60°C but not exceeding 93°C are not included in the category of flammable liquids. For hazardous goods classified as flammable liquids, the packaging groups are divided into three categories, with specific classification rules consistent with GHS flammable liquids categories 1-3.
Additionally, in the storage process, according to the "Code for Fire Protection Design of Buildings" GB50016-2014, our country defines flammable liquids as those with a flash point below 60°C. Among them, liquids with a flash point below 28°C need to be stored in Class A warehouses, while liquids with a flash point not less than 28°C but below 60°C need to be stored in Class B warehouses. It is important to note that, whether under the GHS system or UN TDG rules, the critical flash point temperature for classifying flammable liquids below 60°C is 23°C, while in the storage process, the distinguishing flash point temperature is 28°C.
Furthermore, in different countries and regions, there are slight differences in the GHS classification of flammable liquids. CIRS provides a simple comparison between China, the United States, and the European Union.
China
According to the 'Rules for classification and labelling of chemicals—Part 7: Flammable liquids' GB 30000.7-2013 implemented in 2014, flammable liquids are divided into 4 categories, consistent with the UN GHS.
European Union
According to the EU CLP Regulation (Classification, Labeling and Packaging of Substances and Mixtures), the definition of flammable liquids is slightly different from the UN GHS. Under the CLP Regulation, liquids with a flash point not exceeding 60°C are considered flammable liquids. Therefore, in the EU, flammable liquids are only classified into Category 1, Category 2, and Category 3, and the classification of Category 4 under the UN GHS system is not adopted.
United States
In the Hazard Communication Standard (HCS) issued by OSHA (Occupational Safety and Health Administration) in the United States, flammable liquids are also divided into 4 categories, consistent with China's GB 30000.7 and the UN GHS. However, it is worth noting that the standard NFPA 30-2021 Flammable and Combustible Liquid Code issued by the National Fire Protection Association (NFPA) in the United States has slightly different flash points and initial boiling point temperatures for flammable liquids. The flash point threshold temperatures are 22.8°C, 37.8°C, 60°C, and 93°C; while the initial boiling point threshold temperature is 37.8°C.
Finally, CIRS summarizes as follows:
Standards/Regulations |
Flash Point |
Initial Boiling Point |
|||
Category 1 |
Category 2 |
Category 3 |
Category 4 |
||
UN GHS |
<23℃ |
<23℃ |
≥23℃,≤60℃ |
>60℃,≤93℃ |
35℃ |
GB 30000.7-2013 |
<23℃ |
<23℃ |
≥23℃,≤60℃ |
>60℃,≤93℃ |
35℃ |
EU CLP |
<23℃ |
<23℃ |
≥23℃,≤60℃ |
|
35℃ |
OSHA HCS |
<23℃ |
<23℃ |
≥23℃,≤60℃ |
>60℃,≤93℃ |
35℃ |
NFPA |
<22.8℃ |
<22.8℃ |
≥22.8℃,≤60℃ |
>60℃,≤93℃ |
37.8℃ |
GB 50016 |
<28℃ |
≥28℃, <60℃ |
|
|
|
UN TDG |
<23℃ |
<23℃ |
≥23℃,≤60℃ |
|
35℃ |
The classification of flammable liquids is an important part of chemical safety management. By comparing GHS, UN TDG, and the regulatory standards of China, the United States, and the United States, we can find the commonalities in the classification of flammable liquids in different links and different countries, as well as the differences in specific details. Understanding these similarities and differences can help companies better comply with various national regulations in production and trade, ensuring the safe use and management of chemicals.