Dangerous Goods Classes — Classification and Verification for Sea and Air Transport
Interlink編集部What Are Hazard Classes?
Hazard classes categorize dangerous goods based on their transport-related risks.
In international transport, dangerous goods are classified from Class 1 to Class 9. This classification is linked with the UN number, proper shipping name, packaging group, labels, marks, hazardous material declaration, stowage, segregation requirements, storage conditions, and acceptance eligibility.
For freight forwarder operations, the hazard class serves as fundamental information used by shipping lines, airlines, warehouses, CFS, customs brokers, and trucking companies to determine whether they can accept the hazardous cargo.
Even for the same chemical, transport conditions, compatibility for consolidation, storage eligibility, air carriage acceptance, labeling, documentation, and packaging requirements vary depending on the hazard class. Therefore, an accurate confirmation based on the SDS and hazardous material declaration is essential.
Scope Covered in This Article
| Item | Contents Covered in This Article | Contents Covered in Other Articles |
|---|---|---|
| Basics of Hazardous Materials Classes | Covers the concept of categorizing hazardous materials by types of hazards into Classes 1 through 9. | Final classification judgments for individual cargo should be confirmed using SDS, hazardous materials evaluation documents, manufacturers, and hazardous materials specialists. |
| Overview of Classes 1 to 9 | Summarizes the main contents of each class, representative cargo examples, and practical points for freight forwarders. | Detailed application conditions and special provisions for each class should be referenced from the IMDG Code and IATA Dangerous Goods Regulations. |
| Misunderstandings about Class Numbers | Explains that class numbers indicate types of hazards, not the severity or ranking of danger. | Assessment of hazard severity for individual cargo and expert judgments in case of incidents should be confirmed with hazardous materials specialists and relevant parties. |
| Relationship with UN Numbers | Covers that hazardous materials classes should be checked together with the UN number, proper shipping name, packaging group, and subsidiary hazards. | Details on proper shipping names and special provisions by UN number are covered in the UN Numbers article. |
| Primary Hazards and Subsidiary Hazards | Explains that not only the primary class but also subsidiary hazards affect labels, segregation, allowed combinations, and storage conditions. | Specific subsidiary hazard determinations and segregation requirements should be confirmed using SDS, DGD, and hazardous materials specialist references. |
| Importance of Class 9 | Clarifies that Class 9, though categorized as "Miscellaneous," is not a minor classification and frequently applies to lithium batteries, dry ice, magnetic materials, etc. | Individual conditions for lithium battery transport, dry ice, and magnetic materials should be checked in their respective articles and carrier conditions. |
| Differences between Maritime and Air Transport | Covers that the same class may have differing verifying authorities, quantity limits, packaging, and acceptance conditions between maritime and air transport. | Details for maritime transport are covered by the IMDG Code, and air transport details by the IATA Dangerous Goods Regulations article. |
| Impact on CFS, Warehouses, and Consolidation | Explains how hazardous materials classes affect CFS in-gate, warehouse storage, LCL consolidation, and acceptance for inland delivery. | Details on CFS hazardous materials acceptance, hazardous materials warehouses, and consolidation restrictions are covered in their respective articles. |
Role of Hazard Classes
Hazard classes serve as a classification system enabling all parties involved in transport to share a common understanding of the nature of hazardous materials.
Hazardous goods can present various dangers such as explosiveness, flammability, toxicity, corrosiveness, oxidizing properties, radioactivity, and environmental harm.
Organizing these into Classes 1 through 9 helps facilitate decisions on packaging, labeling, marking, stowage, segregation, documentation, storage, and acceptance.
| Items Related to Hazard Classes | Practical Meaning | Verification Stage | Risks of Inadequate Verification |
|---|---|---|---|
| Labels and Marks | Determines the hazards that should be indicated on the external packaging. | Verified during CFS in-gate, air terminal in-gate, and shipping line or airline acceptance checks. | Entry refusal, acceptance rejection, and label correction costs may occur. |
| Packaging | Confirms container and outer packaging conditions appropriate to the hazard. | Checked before shipper packing, repacking, and hazardous materials declaration. | Inadequate packaging can result in shipment or air transport being halted. |
| Stowage and Segregation | Confirms whether the cargo can be placed near other goods. | Verified during maritime transport, at CFS, hazardous goods warehouses, and LCL consolidation. | May cause prohibition of mixed loading, separate shipment arrangement, or reconsignment. |
| Acceptance | Determines whether shipping lines, airlines, warehouses, or CFS will accept the cargo. | Checked at quotation, booking, and pre-in-gate confirmation stages. | Acceptance refusal after booking is possible. |
| Documentation | Confirms consistency with hazardous materials declaration and Safety Data Sheets (SDS). | Verified during Dangerous Goods Declaration (DGD) preparation, document verification, and customs clearance. | Document discrepancies can prevent relevant parties from deciding on acceptance. |
| Storage and Delivery | Confirms whether warehouses and domestic delivery companies accept the hazard class. | Checked when arranging hazardous goods warehouses, temporary storage, and domestic delivery. | May lead to warehouse refusal, delivery denial, or delivery delays. |
Main Categories of Hazard Classes
Hazard classes are organized from Class 1 to Class 9. The class number indicates the type of hazard rather than the severity or ranking of danger.
| Class | Overview | Typical Cargo | Points of Attention in Freight Forwarder Practice |
|---|---|---|---|
| Class 1 | Explosives and explosive substances. | Propellants, firecrackers, pyrotechnic articles, signaling devices, etc. | Acceptance in general freight forwarding practice is usually limited; specialized verification is often required. |
| Class 2 | Gases. | Compressed gases, liquefied gases, aerosols, refrigerants, gas cylinders, etc. | Check container type, pressure, flammability, toxicity, air transport eligibility, and domestic storage and delivery conditions. |
| Class 3 | Flammable liquids. | Paints, inks, adhesives, solvents, fragrances, alcohols, cleaning agents, etc. | Confirm flash point, container classification, quantity, air transport eligibility, and storage permissions under fire safety laws. |
| Class 4 | Flammable solids. | Matches, metal powders, flammable solids, spontaneously combustible substances, substances generating flammable gases on contact with water, etc. | Check for moisture sensitivity, heat generation, spontaneous ignition risk, flammable gas generation, and segregation requirements from other cargo. |
| Class 5 | Oxidizing substances and organic peroxides. | Oxidizers, peroxides, bleaching agent raw materials, disinfectant raw materials, resin curing agents, etc. | Verify compatibility with flammable cargo, temperature control, decomposition/heat generation risks, segregation, and acceptance conditions of shipping lines and CFS. |
| Class 6 | Toxic and infectious substances. | Toxic chemicals, reagents, medical and diagnostic cargo, infectious substances, etc. | Check impact on human health, leak response procedures, storage conditions, and acceptance by delivery companies. |
| Class 7 | Radioactive materials. | Radioisotopes, radioactive materials used for medical and research purposes, etc. | Highly specialized; requires separate regulations, permits, and verification by specialized companies compared to regular cargo. |
| Class 8 | Corrosive substances. | Acids, alkalis, corrosive chemicals, battery acid, etc. | Confirm potential damage from leaks, compatibility with other cargo, container condition, and warehouse storage conditions. |
| Class 9 | Miscellaneous hazardous materials and articles. | Lithium batteries, magnetic materials, dry ice, environmentally hazardous substances, etc. | Though labeled "miscellaneous," this category is not minor; it includes frequently handled cargo requiring individual acceptance checks for air and marine transport. |
Hazard classes serve as an initial reference for the type of hazard. Actual transport eligibility should be confirmed by considering the UN number, proper shipping name, packaging group, subsidiary hazards, quantity, packing form, mode of transport, and acceptance conditions of shipping lines, airlines, CFS, and warehouses.
Class Numbers Do Not Indicate the Level of Danger
A common misconception about hazardous materials classes is the belief that "the higher the Class number, the greater the danger."
This is incorrect. Hazardous materials classes represent categories of risk types, not a ranking of how dangerous they are.
| Misconception | Correct Understanding | Practical Considerations | Documents / Parties to Check |
|---|---|---|---|
| Class 9 is the most dangerous because it has the highest number | Class 9 categorizes miscellaneous harmful substances and does not indicate a hierarchy of danger. | Includes frequently encountered cargo like lithium batteries for which condition confirmations are critical. | SDS, UN number, dangerous goods declaration, carrier conditions |
| Class 8 is always more dangerous than Class 3 | Class 3 refers to flammable substances, Class 8 to corrosive materials; these are different types of hazards. | Fire risk and corrosion risk are not directly comparable. | SDS, hazard class, packaging group, storage conditions |
| Cargo in the same class can be treated identically | Handling can vary within the same class depending on UN number, packaging group, subsidiary hazards, quantity, and packaging. | Decisions on acceptance or compatibility should not be based on class alone. | SDS, DGD, shipping line, CFS, hazardous goods warehouse |
| Class 9 cargo can be handled lightly because it is "miscellaneous" | Class 9 includes cargo with stringent condition requirements in air and maritime transport. | Items like lithium batteries, dry ice, and magnetic materials require individual verification. | SDS, product specifications, airlines, shipping lines |
Freight forwarders should use hazard classes not as a numeric danger scale but as information indicating the type of hazard the cargo presents during transport.
Relationship with UN Numbers
Hazardous materials classes should be confirmed together with the UN number.
The UN number is a four-digit code used to identify hazardous materials. Each UN number is associated with a proper shipping name, hazard class, packaging group, label, packing requirements, special provisions, and other details.
| Verification Item | Meaning | Verification Notes | Risk of Insufficient Verification |
|---|---|---|---|
| UN Number | A four-digit code identifying the hazardous material. | Confirm it together with the proper shipping name, not just the number alone. | May result in incorrect handling as a different cargo. |
| Proper Shipping Name | The official name used for hazardous materials transportation. | May differ from the invoice description. | Can cause errors in the Dangerous Goods Declaration (DGD) and booking information. |
| Hazard Class | Classification indicating the primary hazard. | Relates to labeling, stowage, segregation, and acceptance conditions. | Leads to label deficiencies, misjudged consolidation, or refusal of acceptance. |
| Packaging Group | Categorization relating to degree of hazard and packaging conditions. | If applicable, it affects packing methods and quantity limits. | May cause mistakes in packing standards or quantity restrictions. |
| Subsidiary Hazard | Hazard(s) in addition to the primary class. | Affects additional labeling, segregation, storage, and consolidation eligibility. | Overlooking subsidiary hazards may cause insufficient labeling or segregation. |
Freight forwarders should not rely solely on the UN number or hazard class for judgment. They must verify a combination of the UN number, proper shipping name, hazard class, packaging group, quantities, packaging form, and mode of transport to confirm acceptance conditions with shipping lines, airlines, and warehouses.
Primary and Subsidiary Hazards
Hazardous materials may have not only a primary hazard class but also subsidiary hazards.
The primary hazard refers to the main hazard characteristic of the cargo. The subsidiary hazard refers to an additional hazard that exists alongside the primary hazard of the cargo.
| Category | Meaning | Practical Impact | Documents to Check |
|---|---|---|---|
| Primary Hazard | The main hazard class of the hazardous material. | Forms the basis for labels, declarations, transport conditions, and acceptance decisions. | SDS, Dangerous Goods Declaration, Hazard Classification Materials |
| Subsidiary Hazard | An additional hazard present alongside the primary hazard class. | Affects additional labeling, segregation, compatibility for shipment, storage conditions, and emergency response measures. | SDS, DGD, Subsidiary Hazard Section, Hazard Classification Materials |
| Cargo with Multiple Hazards | Cargo exhibiting combined hazards such as flammability and toxicity, or corrosiveness and toxicity. | Relying only on the primary hazard may lead to incorrect acceptance or segregation decisions. | SDS, Manufacturer Confirmation, Shipping Line / Airline Responses |
If subsidiary hazards exist, referring only to the primary hazard class may result in mistakes in labeling, segregation, stowage, storage, or compatibility assessments.
Typical Examples of Subsidiary Risks
Subsidiary risks are important in practical decisions on hazardous material classes. In the following combinations, it is necessary to confirm not only the primary class but also the subsidiary risks.
| Combination Example | Common Issues | Points to Confirm | Actions if Issues Are Found |
|---|---|---|---|
| Flammable Liquids + Toxicity | Overlap of fire hazard and harm to human health. | Confirm primary class, subsidiary risks, labels, emergency response, and airline conditions. | Verify additional labeling, acceptance conditions, and emergency response information. |
| Corrosive + Toxicity | Leakage may cause both corrosive damage and health hazards. | Check packaging, leak response procedures, warehouse storage conditions, and carrier requirements. | Reconfirm warehouse and carrier acceptance conditions. |
| Oxidizing + Corrosive | Compatibility with other cargo, reaction on leakage, and container damage are concerns. | Confirm segregation, compatibility for mixed loading, storage segregation, and CFS acceptance conditions. | Consider separate compartments, separate containers, separate warehouses, or separate shipments. |
| Gases + Flammability | Both pressure vessels and flammability must be considered. | Check gas type, container specifications, temperature conditions, air transport eligibility, and inland delivery restrictions. | Individually verify with airlines, carriers, and warehouses. |
| Environmental Hazards + Other Classes | May involve marine pollutant designation and environmental hazard declaration requirements. | Confirm marine pollutant status, labeling, SDS, and dangerous goods declarations. | Reconfirm labeling and declaration requirements for maritime transport. |
Subsidiary risks should be confirmed using the SDS, dangerous goods declarations, and hazard classification documents. If there are inconsistencies regarding subsidiary risks between documents, it is important to consult with the shipper or manufacturer and finalize the classification before proceeding with arrangements.
Practical Importance of Class 9
Class 9 covers miscellaneous hazardous substances and articles.
Despite being labeled as "miscellaneous," Class 9 frequently presents challenges in freight forwarder operations.
| Common Cargo Under Class 9 | Points of Attention | What to Check | Actions When Issues Arise |
|---|---|---|---|
| Lithium Batteries | Handling varies depending on whether batteries are stand-alone, packed with equipment, or incorporated into equipment. | Verify UN number, battery type, UN38.3 certification, airline conditions, packaging, and labeling. | Confirm lithium battery transport requirements; if acceptance is declined, consider alternative routing. |
| Magnetic Materials | Can cause issues in air transport. | Confirm presence of magnetism, airline conditions, and whether measurement documentation is required. | Obtain prior confirmation from the airline and secure measurement documentation if needed. |
| Dry Ice | Used as a refrigerant; quantity and labeling must be checked for air transport. | Check quantity used, packaging, ventilation, airline conditions, and label/marking compliance. | Adjust quantity or labeling as needed; confirm airline and warehouse acceptance conditions. |
| Environmentally Hazardous Substances | May require declarations related to marine pollutants or environmental hazards. | Review SDS, applicability as marine pollutant, hazardous materials declaration, and markings. | Ensure proper marking and declaration for maritime transport. |
Class 9 is frequently encountered in freight forwarder operations yet often overlooked. Special caution is warranted for lithium batteries, dry ice, and magnetic materials, as their hazard status may not be obvious from product names alone and require careful verification.
Differences Between Maritime and Air Transport
Although the hazard classes are the same, the details requiring verification differ between maritime and air transport.
| Verification Item | Maritime Transport | Air Transport | Practical Notes for Freight Forwarders |
|---|---|---|---|
| Primary Regulation | Verification is centered on the IMDG Code. | Verification is centered on the IATA Dangerous Goods Regulations. | Acceptance conditions may differ for the same class between maritime and air transport. |
| Acceptance Criteria | Check conditions of shipping lines, NVOCCs, CFS, consolidation agents, and transshipment ports. | Check conditions of airlines, consolidation agents, courier companies, and airport warehouse facilities. | Confirm conditions not only for the carrier but also for CFS, warehouses, and consolidation agents. |
| Quantity and Packaging | Verified assuming container transport or LCL consolidation. | Quantity limits per package and packaging standards tend to be stricter and more problematic. | Packaging accepted for maritime transport may not be acceptable for air transport. |
| Consolidation and Segregation | Issues arise around CFS, container stowage, onboard loading, and segregation requirements. | Considerations include aircraft loading approval, passenger aircraft restrictions, and cargo-only aircraft conditions. | When changing transport modes, reconfirm consolidation and loading conditions. |
| Common Bottlenecks | Delays often occur at CFS in-gate, hazardous cargo booking, LCL consolidation, and shipping line approval. | Delays occur due to airline confirmation, warehouse in-gate, packaging and label checks, and quantity restrictions. | Avoid promising the same transit time as general cargo at the quotation stage. |
| Key Points | Even if accepted for maritime transport, shipments may be halted due to CFS or consolidation conditions. | Shipment accepted by sea transport may still be rejected for air transport acceptance. | When switching from maritime to air transport, hazardous materials verification must be redone. |
Freight forwarders should not assume hazardous materials accepted for maritime transport are automatically accepted for air transport. When changing transport modes, the hazard class, UN number, quantity, packaging, labels, and airline-specific conditions should be reverified.
Verification Procedures for Freight Forwarders
Hazardous material classes are fundamental information that should be confirmed before booking. Proceeding with a quote or booking without knowing the class could cause delays or stoppages during declaration to shipping lines and airlines, warehouse in-gate, CFS acceptance, or customs document checks.
| Step | What to Confirm | Guidance for Judgment | Common Points of Delay |
|---|---|---|---|
| 1. Check the SDS | Confirm if Section 14 of the SDS includes the UN number, proper shipping name, and hazardous material class information. | Use this as the initial verification of whether the cargo qualifies as hazardous material. | The SDS may be outdated, for a different product, or have section 14 left blank. |
| 2. Cross-check with the Dangerous Goods Declaration | Verify that the class, UN number, proper shipping name, and packaging group on the DGD match those on the SDS. | If discrepancies between documents exist, stop arrangements and seek clarification. | The class or UN number may differ between the SDS and the DGD. |
| 3. Confirm subsidiary hazards | Check for any hazards in addition to the primary class. | Reflect this in additional labeling, segregation requirements, compatibility for consolidation, and storage conditions. | Focusing only on the primary class may lead to overlooking subsidiary hazards. |
| 4. Confirm mode of transport | Verify whether the shipment involves sea transport, air transport, or domestic delivery. | Check acceptance conditions specific to each transport mode. | Mixing up conditions for sea and air transport is common. |
| 5. Confirm acceptance by stakeholders | Confirm whether the shipping line, airline, CFS, warehouse, and trucking company can accept the cargo. | This helps prevent situations where regulations permit acceptance but actual practice does not. | The shipping line may accept the cargo but the CFS or warehouse might refuse it. |
| 6. Verify on-site markings | Check labels on outer packaging, UN number markings, GHS labels, lithium battery markings, etc. | Prevent discrepancies between documents and physical markings. | Shipments may be stopped at in-gate due to missing or insufficient labels and marks. |
Verification of SDS, Dangerous Goods Declaration, and Physical Labels
Hazard classes should not be determined solely by the SDS, the dangerous goods declaration, or the physical labels.
Freight forwarders must at least check for consistency among the following information.
| Verification Item | Details to Check | If Discrepancies Are Found | Party to Confirm With |
|---|---|---|---|
| SDS | Check the UN number, proper shipping name, hazard class, packing group, and subsidiary hazards. | Confirm it is the latest version and matches the specific product. | Shipper, Manufacturer |
| Dangerous Goods Declaration | Verify the class, quantity, packaging, packing group, and emergency contact on the DGD. | Cross-check against SDS and invoice, then confirm with the shipper. | Shipper, Dangerous Goods Declarant, Manufacturer |
| Invoice / Packing List | Confirm the product name, model number, quantity, packaging form, and weight. | Ensure consistency with the cargo covered by hazardous materials documentation. | Shipper, Exporter, Packer |
| Physical Labels / Exterior Markings | Check hazard class labels, UN number markings, and handling instructions. | Make any necessary label corrections or reconfirmations prior to in-gate. | Shipper, Warehouse, CFS, Airline Handling Facilities |
| Non-Hazardous Cargo Certificate | Verify the basis for non-hazardous classification, the applicable product, and the issue date. | Check for contradictions with SDS or physical markings. | Shipper, Manufacturer, Hazardous Materials Specialist |
Errors in hazard classification are not mere paperwork mistakes; they risk miscommunicating the cargo’s hazards to involved parties.
Comparison Table of Freight Forwarders’ Involvement
| Category | What Can Be Supported | What Should Not Be Concluded | Practical Response |
|---|---|---|---|
| Initial Confirmation of Hazard Classes | Confirm SDS, DGD, UN number, proper shipping name, and hazard class. | Determine class based only on the product name. | Obtain materials from the shipper or manufacturer and verify consistency among documents. |
| Confirmation of Classification | Verify that the hazard class indicated in documents provides all information necessary for transport arrangements. | Act as the final authority on chemical classification and decide classification independently. | If there are doubts, consult with the shipper, manufacturer, or hazardous materials specialists. |
| Verification of Subsidiary Hazards | Check hazards other than the primary class, additional labels, and segregation requirements. | Judge transport or storage compatibility solely based on the primary hazard class. | Cross-check SDS, DGD, and conditions set by shipping lines and CFS. |
| Confirmation with Shipping Lines and Airlines | Present the relevant hazard class, UN number, quantity, and packaging to confirm acceptance. | Assume that if regulations permit, the carrier must accept the cargo. | Record each carrier’s response and specific conditions. |
| Confirmation with CFS and Warehouses | Verify whether in-gate, storage, and consolidation of the hazard class are permitted. | Assume that if accepted by the shipping line, the CFS or warehouse will also accept it. | Individually confirm with CFS, hazardous materials warehouses, and inland delivery companies. |
| Confirmation of Class 9 Cargo | Check specific conditions for lithium batteries, dry ice, magnetic materials, etc. | Treat Class 9 as “others” and assume they can be handled lightly. | Verify transport conditions by item, airline requirements, and marking requirements. |
| Document and Physical Goods Verification | Confirm consistency of SDS, DGD, invoice, packing list, and outer packaging markings. | Assume that document submission makes physical label verification unnecessary. | Confirm labels, UN number markings, and outer packaging before in-gate. |
| Situations with Remaining Doubts | Hold off on arrangements and request additional verification from the shipper, manufacturer, or specialists. | Proceed with booking, in-gate, or airline warehouse in-gate despite inconsistencies. | Obtain corrected documents and resubmit to all parties involved. |
Common Practical Issues
| Case | Issue | Documents / Parties to Check | Recommended Approach |
|---|---|---|---|
| Hazardous class differs between SDS and hazardous materials declaration | The correct classification cannot be confirmed, leaving shipping lines, airlines, and CFS unable to decide. | SDS, DGD, invoice, manufacturer confirmation documents | Confirm with the shipper or manufacturer and unify the documents to reflect the correct classification. |
| UN number is known, but class and packaging group are not confirmed | Packaging, labeling, and acceptance feasibility cannot be determined. | SDS, DGD, hazardous materials classification documents | Obtain the necessary information before confirming with shipping lines or airlines. |
| Overlooking subsidiary hazards | Additional labeling, segregation, compatibility for mixed loading, and storage conditions may be missed. | SDS, DGD, subsidiary hazard section, shipping line responses | Check not only the primary class but also the subsidiary hazard section. |
| Confusing maritime and air transport requirements | Cargo accepted for sea transport may be rejected for air transport. | IMDG Code, IATA Dangerous Goods Regulations, airline responses | Confirm regulations and carrier conditions separately for each transportation mode. |
| Warehouse or CFS cannot accept certain hazardous classes | Only shipping line acceptance was checked; CFS and warehouse conditions were not confirmed. | CFS replies, hazardous materials warehouse replies, shipping line replies | Confirm acceptance conditions of CFS, hazardous materials warehouses, and inland delivery companies. |
| Segregation requirements not confirmed for mixed cargo | Potential issues with compatibility between cargos or segregation requirements. | SDS, DGD, mixed cargo operator replies, CFS conditions | Confirm hazardous materials compatibility, segregation requirements, and CFS mixed cargo conditions. |
| External labels and documented class do not match | Mismatch between the actual cargo and documents can lead to gate-in or acceptance refusal. | Photos of the cargo, DGD, SDS, invoice, packing list | Verify the actual markings, DGD, SDS, and invoice before gate-in. |
| Underestimating Class 9 and treating it as general cargo | Individual requirements for lithium batteries, dry ice, magnetic materials, etc., are not confirmed. | SDS, product specifications, UN number, airline and shipping line responses | Confirm individual requirements for Class 9 and prepare necessary markings, documents, and packaging accordingly. |
4-Column Verification Checklist
| Verification Situation | Party to Confirm | Items to Confirm | Actions if Issues Arise |
|---|---|---|---|
| When receiving a cargo inquiry that may involve hazardous materials | Shipper / Manufacturer | Check SDS Section 14, UN number, proper shipping name, hazard class, and packaging group. | If information is insufficient, do not finalize quotation or arrangements as general cargo. |
| When receiving SDS and Dangerous Goods Declaration (DGD) | Shipper / Hazardous Materials Declarant | Verify that hazard class, UN number, proper shipping name, packaging group, and quantity match. | If discrepancies exist, request corrections from shipper or manufacturer. |
| When handling cargo with subsidiary hazards | Shipper / Manufacturer / Hazardous Materials Specialist | Confirm main hazard class, subsidiary hazards, additional labels, and segregation requirements. | Reconfirm additional labels, storage conditions, and compatibility for combined loading. |
| When arranging maritime transport | Shipping Line / NVOCC / CFS / Consolidation Operator | Check handling per IMDG Code, carrier acceptance, CFS in-gate eligibility, and LCL consolidation permission. | If not accepted, consider alternative shipping line, different CFS, FCL shipment, or another service. |
| When arranging air transport | Airline / Airfreight Agent / Courier Company | Confirm handling under IATA Dangerous Goods Regulations, quantity limits, packaging, and passenger aircraft carriage eligibility. | If not accepted, consider cargo aircraft, alternate airline, or maritime transport. |
| When bringing cargo into CFS or warehouse | CFS / Hazardous Materials Warehouse / Domestic Delivery Company | Verify acceptance of the hazard class, storage conditions, in-gate date, and combined loading permission. | If rejected, consider alternative CFS or hazardous materials warehouse, or reschedule in-gate date. |
| When handling Class 9 cargo | Shipper / Manufacturer / Airline / Shipping Line | Confirm individual conditions for lithium batteries, dry ice, magnetic materials, and environmentally hazardous substances. | If individual conditions are not met, consider repackaging, alternative service, or a different transport mode. |
| When checking physical labels | Shipper / Warehouse / CFS / Air freight warehouse | Ensure consistency between hazard class labels, UN numbers, GHS markings, and lithium battery labels with documents. | Before in-gate, correct markings, relabel, or amend documentation as necessary. |
Example 1: Case Where Hazard Classes Differed Between SDS and DGD
In this case, the shipper submitted both an SDS and a Dangerous Goods Declaration, but the SDS indicated Class 3 while the DGD listed Class 8.
Under these conditions, the shipping line, airline, CFS, and warehouse cannot accurately assess the hazard. Possible causes include an outdated SDS, an SDS for a different product, errors in DGD preparation, or a change in classification.
The freight forwarder should confirm with the shipper or manufacturer to identify the correct product, the latest SDS, the correct UN number, the official proper shipping name, hazard class, and packaging group.
Until the classification is confirmed, booking, CFS in-gate, and delivery to the airline’s warehouse should not proceed.
Example 2: Underestimating Class 9 Lithium Batteries
This case involved a shipment requested by the shipper as "electronic components" that included lithium batteries classified under Class 9.
Class 9 refers to "Miscellaneous Hazardous Materials," but lithium batteries are a representative cargo requiring careful condition checks for air transport, maritime transport, CFS in-gate, and courier acceptance.
The freight forwarder must verify whether the shipment corresponds to UN3480, UN3481, UN3090, or UN3091, identify if the batteries are standalone, included with equipment, or incorporated into equipment, and confirm compliance with UN38.3, packaging, markings, and airline acceptance conditions.
It is critical to confirm transport conditions for each specific item rather than assuming Class 9 cargo can be handled lightly.
Example 3: Case Where Secondary Hazards Were Overlooked, Resulting in Prohibition of Consolidation
A case where cargo consolidation at a CFS was arranged based solely on the primary hazard class, but secondary hazards were identified later, leading to a ban on consolidation.
When secondary hazards exist, additional labeling, segregation, storage classification, acceptance for consolidation, and emergency response requirements may change.
The freight forwarder should review the SDS, Dangerous Goods Declaration (DGD), and hazardous materials classification documents, confirming not only the primary hazard class but also the secondary hazards section.
If the CFS or consolidation operator cannot accept the cargo, alternative solutions such as using a different CFS, shipping by separate vessel, FCL shipping, or temporary storage at a hazardous materials warehouse should be considered.
Example 4: Case of Switching Dangerous Goods Accepted for Sea Transport to Air Transport
This case involves a shipper requesting to switch hazardous cargo from sea to air transport due to shipment delays.
Even if the cargo class is accepted for sea transport, air transport may impose quantity limits, packaging standards, passenger aircraft restrictions, or airline-specific conditions that could result in rejection.
The freight forwarder should reconfirm the handling under IATA Dangerous Goods Regulations, airline conditions, packaging, labeling, quantity per package, and any dedicated cargo aircraft restrictions.
If the airline refuses acceptance, options such as continuing sea transport, using a cargo-only flight, selecting a different airline or route, or rescheduling delivery should be proposed to the shipper.
Information to Confirm with the Shipper
For cargo involving hazard classes, freight forwarders should confirm the following information with the shipper early in the process.
- Whether the hazard class is indicated in Section 14 of the SDS.
- Whether the UN number, proper shipping name, hazard class, and packaging group have been verified.
- Whether the hazard class on the dangerous goods declaration matches the hazard class on the SDS.
- Whether any subsidiary risks exist.
- Whether handling differs between maritime and air transport.
- Whether the shipping line or airline accepts that hazard class.
- Whether the warehouse, CFS, and trucking companies accept that hazard class.
- Whether there are any issues with segregation or compatibility for mixed loading.
- Whether outer package labels, UN number markings, and actual cargo markings match the documentation.
- If the cargo falls under Class 9, whether specific conditions for items such as lithium batteries, dry ice, or magnetized materials have been confirmed.
Common Misunderstandings
Misinterpreting hazard class numbers, class names, SDS entries, or actual markings can lead to arrangement errors.
| Misunderstanding | Practical Consideration | What Should Be Confirmed |
|---|---|---|
| A higher number means more dangerous | Class numbers indicate the type of hazard, not the degree of danger. | Confirm the class name, UN number, proper shipping name, and packaging group. |
| Class 9 is "miscellaneous," so it is less important | Class 9 includes frequently encountered cargo such as lithium batteries. | Check individual item transport conditions, airline restrictions, and markings. |
| Cargo of the same class can be consolidated | Even within the same class, UN numbers, subsidiary hazards, and segregation requirements affect compatibility. | Verify compatibility, segregation conditions, and CFS and carrier requirements. |
| Having the class listed on the SDS is sufficient | The SDS may be outdated, contain inadequate transport information, or conflict with the DGD or actual markings. | Cross-check the SDS, DGD, invoice, and actual markings. |
| If accepted as a class on sea transport, it will be accepted for air transport | Air transport has different quantity limits, packaging, and loading conditions. | Check IATA Dangerous Goods Regulations, airline conditions, and passenger aircraft carriage restrictions. |
| Only the primary hazard class needs to be considered | Subsidiary hazards affect additional labels, segregation, and storage conditions. | Confirm subsidiary hazards, additional labels, compatibility, and emergency response procedures. |
| If the shipping line accepts the class, the CFS and warehouse will also accept it | Acceptance decisions differ among shipping lines, CFS, warehouses, and inland delivery companies. | Confirm CFS in-gate conditions, hazardous goods warehouse acceptance, and inland delivery company acceptance. |
| If an outer package label is applied, document verification is not necessary | Labels on outer packaging may not match the SDS, DGD, or invoice. | Verify outer package markings, SDS, DGD, invoice, and packing list. |
Points Freight Forwarders Should Be Aware Of
Hazard classes serve as a fundamental reference for assessing the safety and operational feasibility of hazardous materials transport.
- Check the hazard class in the transport information section of the SDS.
- Verify it together with the UN number, proper shipping name, and packaging group.
- Do not mistake the class number as an indicator of the relative strength of hazard.
- Confirm whether subsidiary hazards are present.
- Review conditions separately for maritime and air transport.
- Do not overlook Class 9: confirm specific conditions for lithium batteries, dry ice, magnetic materials, and similar items.
- Pre-check acceptance eligibility with warehouses, CFS, and trucking companies.
- Cross-reference the SDS, hazardous material declaration, invoice, packing list, and actual cargo labels.
- If there are doubts, consult in advance with the shipper, manufacturer, shipping line, airline, CFS, or hazardous materials specialists.
Summary
Hazard classes categorize hazardous materials according to the risks they pose during transport.
In international transport, hazardous materials are classified from Class 1 to Class 9 and are used in conjunction with the UN number, proper shipping name, packaging group, labels, markings, hazardous material declaration, stowage and segregation requirements, and acceptance criteria.
The hazard class number does not indicate the degree of danger. For example, Class 3 represents flammable liquids, Class 8 corrosive substances, and Class 9 miscellaneous hazardous materials, showing types of hazards rather than ranking severity.
Freight forwarders should not determine hazard classes alone. They need to verify them together with the UN number, proper shipping name, packaging group, subsidiary hazards, quantity, packaging configuration, mode of transport, and acceptance criteria of shipping lines, airlines, CFS, and warehouses.
Confirming the hazard class is the entry point for hazardous materials transport and affects packaging, labeling, documentation, compatibility for consolidation, warehousing, air carriage eligibility, and emergency response. If discrepancies exist between documents and actual markings, it is essential to confirm with the shipper or manufacturer before proceeding.
The key takeaway from this article is that hazard classes should not be memorized simply as class numbers, but handled as practical information linked with the UN number, proper shipping name, subsidiary hazards, transport mode, and acceptance conditions of CFS, warehouses, and carriers.
