A Shipper's Guide: Understanding and Shipping GHS-Classified Flammable Solids from China
Author: International Logistics Expert, Shenzhen, China
As a leading freight forwarder based in Shenzhen, China, we frequently handle international shipments of chemical products, including those classified as hazardous. Understanding the regulatory framework governing these goods is crucial for ensuring safe, compliant, and efficient global supply chains. This guide aims to clarify the classification, labeling, and transportation requirements for Flammable Solids under the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), a system adopted by China and most of our international trading partners.
1. What Are GHS Flammable Solids?
According to the GHS, a Flammable Solid is a solid substance or mixture that is readily combustible or may cause or contribute to fire through friction. In practical terms, this typically refers to powdery, granular, or pasty materials that can be easily ignited by a brief contact with an ignition source (e.g., a match) and where the flame spreads rapidly.
2. The GHS Hazard Classification: Two Categories
For transportation purposes, the GHS sub-divides Flammable Solids into two categories, with Category 1 posing a greater hazard than Category 2. The classification is determined by standardized burn rate tests.
| Category | Criteria (Non-Metallic Powders/Mixtures) | Criteria (Metallic Powders)* | Relative Hazard |
|---|---|---|---|
| Category 1 | Burn time < 45 seconds AND the wetted section does NOT stop the flame. | Burn time ≤ 5 minutes | Higher |
| Category 2 | Burn time < 45 seconds BUT the wetted section DOES stop the flame for at least 4 minutes. | Burn time 5 min and ≤ 10 minutes | Lower |
*Metallic Powders: Powders of metals or metal alloys.
3. Communication & Transportation: Labels and Packaging
The GHS classification directly dictates the required hazard communication on packages and their transport conditions under regulations like the IMDG Code (Sea) and IATA DGR (Air). The Chinese national standard GB 30000.8-2013 is fully aligned with GHS on this matter.
| GHS Classification | Signal Word | Hazard Statement (Code) | Pictogram | Transport Information (TDG/UN Model) | ||
|---|---|---|---|---|---|---|
| UN Proper Shipping Name | Class/Division | Packing Group | ||||
| Flammable Solids, Cat. 1 | Danger | H228: Flammable solid. | 🔥 Flame | FLAMMABLE SOLID, ... | 4.1 | II |
| Flammable Solids, Cat. 2 | Warning | H228: Flammable solid. | 🔥 Flame | FLAMMABLE SOLID, ... | 4.1 | III |
Key Takeaways for Shippers:
- Packing Group (PG) is critical: It defines the required packaging performance standards. PG II (Category 1) requires more robust packaging than PG III (Category 2).
- The UN Class 4.1 and correct Packing Group must be marked on the package and declared on all shipping documents (DGD, MSDS/SDS, Commercial Invoice, Bill of Lading/Air Waybill).
4. How Are Flammable Solids Classified? The Testing Process
The classification process, referenced in the UN Manual of Tests and Criteria, involves a two-step procedure to ensure safety:
- Screening Test: A sample is formed into a powder trail. A high-temperature flame is applied. If the sample does not ignite and propagate flame within a set time, it is not classified as a flammable solid. If it does propagate, it proceeds to the main test.
- Burn Rate Test: The sample is formed into a specific shape and ignited. The time to burn a 100mm length is measured to calculate the burn rate. For non-metals, a wetted section is also created to see if it stops the flame. The results from six trials determine the final category.
5. Relevant Testing Standards in China
Chinese manufacturers and testing laboratories determine classification using national standards aligned with international protocols, such as:
- GB/T 21618-2008: Test method for burning rate of flammable solids (dangerous goods).
- SN/T 1828.11-2019: Test method for classification of import and export dangerous goods - Part 11: Flammable solids.
Conclusion: Ensuring Compliant and Safe Shipments
For international buyers sourcing chemicals from China, verifying the GHS classification of your products is the first and most critical step. A correct Safety Data Sheet (SDS) with Section 14 (Transport information) properly completed is essential. As your logistics partner, we rely on this accurate data to:
- Select the correct UN-certified packaging.
- Apply regulatory hazard labels and markings.
- Prepare the mandatory Declaration for Dangerous Goods (DGD) for carriers.
- Book cargo with carriers approved to handle Class 4.1 Dangerous Goods.
Proper classification is not just a regulatory requirement—it is the foundation for the safety of your cargo, the transportation crew, the environment, and the integrity of your supply chain. Always insist on compliant documentation from your suppliers.
(References: UN GHS (Rev.10), UN Model Regulations (Rev.23), UN Manual of Tests & Criteria (Rev.8))
Quick Reference: Flammable Solids Classification Summary
| Item | Category 1 (Higher Hazard) | Category 2 (Lower Hazard) |
|---|---|---|
| Signal Word | Danger | Warning |
| Hazard Statement | H228 - Flammable solid | |
| UN Class | Class 4.1 - Flammable Solids | |
| Packing Group | PG II | PG III |
| Non-metal burn time | < 45 sec, wetted section does NOT stop flame | < 45 sec, wetted section stops flame ≥ 4 min |
| Metal powder burn time | ≤ 5 minutes | 5 min and ≤ 10 min |
Disclaimer: This guide is for informational purposes based on UN GHS Rev. 10, UN Model Regulations Rev. 23, and IMDG Code/IATA DGR. Regulations are subject to change. Always consult official sources or professional DG logistics advisors for specific shipments.