由 caicai8478 In global trade and domestic logistics, powdered goods, due to their diverse physical and chemical properties, are a key focus of regulation. An incorrect classification can lead to anything from cargo detention, fines, and returns to serious accidents such as fires, explosions, and poisoning during transport, with unimaginable consequences.
Therefore, accurately determining whether a powder is “general goods” or “dangerous goods” is a fundamental regulatory skill that every professional in the field must master. This article will outline a clear and practical judgment process.
Step 1: Core Principle – Abandon Empiricism, Return to Scientific Data
Judging the properties of powder should never be based on “feelings,” appearance, or past experience with “similar goods.” Many seemingly harmless powders (such as flour, starch, metal powder, and dye powder) can be potentially dangerous under certain conditions. The only reliable basis is a “Certificate of Cargo Transport Conditions” issued by a qualified professional testing institution.
However, companies can conduct preliminary assessments and screenings before and after submitting goods for testing. This not only improves efficiency but also provides a deeper understanding of the risks involved.
Step Two: Preliminary Self-Inspection – Examining the “Identity” and “Properties” of the Goods
Before submitting goods for testing, ask yourself the following key questions:
What is the chemical composition?
Known Chemicals: If the powder is a single known chemical (such as sulfur powder, zinc powder, or sodium persulfate), you can directly consult its Material Safety Data Sheet (MSDS/SDS). Item 14, “Transport Information,” in the MSDS is the gold standard for preliminary assessment. If it displays the UN number and hazard class, it can generally be identified as a dangerous good.
Mixtures or Unknown Substances: For most industrial products, health products, chemical intermediates, and other mixtures, the situation is more complex, and testing is necessary to determine its overall hazard.
What are its physical and chemical properties?
Flammability/Combustibility: Is the powder easily ignited in air? Fine powders have a large surface area, allowing for ample contact with air. Once a certain concentration is reached, even a tiny spark can trigger a dust explosion. This is one of the most common hazardous characteristics of powders.
Oxidizing Properties: Is the powder itself non-flammable, but can it provide oxygen, violently intensifying the combustion of other substances (such as certain peroxides and nitrates)?
Toxicity: Will inhalation, skin contact, or ingestion of the powder cause harm to human health?
Corrosivity: Will the powder corrode metals, skin, etc.?
Water Reactivity: Will the powder release flammable gases (e.g., aluminum powder, zinc powder in water) or generate high heat when it comes into contact with water?
Self-Reactivity/Spontaneous Combustion: Can the powder spontaneously generate heat at room temperature, or spontaneously ignite in air without an open flame?
If the answer to any of the above questions is “yes” or “uncertain,” then the powder is highly suspected of being a hazardous material.
Step 3: Regulatory Framework – Understanding the Core Standards of Classification There are mature international and domestic regulatory systems for the transport of dangerous goods, and their basic principles are similar. The main bases include:
International: United Nations Recommendations on the Transport of Dangerous Goods – Model Regulations (Orange Book)
Maritime: International Maritime Dangerous Goods Code (IMDG Code)
Air Transport: International Air Transport Dangerous Goods Code (IATA DGR)
Domestic: List of Dangerous Goods (GB 12268) and relevant national standards
These regulations classify dangerous goods into nine categories. Categories closely related to powders include:
Class 4: Flammable solids (e.g., sulfur, activated carbon)
Class 4: Substances prone to spontaneous combustion (e.g., certain metal powders)
Class 5.1: Oxidizing substances (e.g., potassium permanganate)
Class 6.1: Toxic substances (e.g., certain pesticide powders)
Class 8: Corrosive substances (e.g., sodium hydroxide powder)
Class 9: Miscellaneous dangerous substances and articles (including substances harmful to the environment)
Special Reminder: Even if they don’t meet the strict definitions above, many powders, due to their physical form potentially posing a hazard to aircraft equipment (such as engines and instruments), are classified as restricted air cargo during air transport and are not truly “general cargo.”
Step Four: Authoritative Assessment – Obtaining the “Certificate of Cargo Transport Conditions”
This is the final and only step with legal and commercial validity.
Choose an Institution: Select an authoritative testing institution accredited by the China National Accreditation Service for Conformity Assessment (CNAS) or by major carriers (such as shipping companies and airlines).
Provide Samples and Information: Provide the testing institution with representative samples and provide information on the product’s chemical composition, manufacturing process, etc., as accurately as possible.
Testing and Assessment: The testing institution will conduct a series of rigorous tests on the samples according to relevant regulations (such as flammability testing, metal content testing, toxicity testing, dust explosiveness testing, etc.) and ultimately issue an assessment certificate.
Interpretation of Results:
Result: “General Cargo”: Congratulations! Transportation can be arranged according to the general cargo process, but attention still needs to be paid to general cargo requirements such as moisture protection and intact packaging.
The result is “Dangerous Goods”: The certificate will clearly list its UN number, correct transport name, hazard class, and packing class. You must strictly adhere to this information, use compliant dangerous goods packaging, entrust transportation to a qualified dangerous goods carrier, and complete all necessary declaration documents.
Summary: A clear decision-making flowchart
Final reiteration:
In the world of powdered goods, “I thought” is the biggest safety hazard and business risk. The Certificate of Cargo Transport Conditions is your “passport” and “protective shield” for legal, safe, and smooth transportation. Under no circumstances should you take chances; always let scientific data be the cornerstone of your decisions.