IMDG Class 9 is the "miscellaneous" dangerous goods class — a catch-all for substances and articles that present a hazard during transport but do not fit the definitions of Classes 1-8. Unlike other classes that share a common hazard mechanism (flammability, toxicity, corrosion), Class 9 groups together fundamentally different hazards: lithium batteries, environmentally hazardous substances, elevated temperature liquids, magnetized materials, genetically modified organisms, dry ice, and asbestos. This makes Class 9 both the broadest and most commercially dynamic DG class, driven especially by the explosive growth of lithium battery and energy storage exports from China.
Our UN3536 Track Record
1,000+ TEU of UN3536 containerized BESS shipped safely from China to Europe, Middle East, and Africa.
SP389-compliant design verification. DG packaging certificates in 3 working days. Zero incidents across all shipments.
Major Class 9 Categories and Their UN Numbers
Lithium Batteries and Energy Storage Systems
- UN3536 — Lithium batteries installed in cargo transport units: Containerized Battery Energy Storage Systems (BESS). This is the UN number that defines the modern energy storage logistics industry. SP389 provides specific provisions for large-format BESS in 20ft and 40ft containers. Great Hensen's core DG specialty. See our UN3536 guide →
- UN3480 — Lithium-ion batteries (standalone): Individual cells and batteries not packed with or contained in equipment. State of charge (SoC) limited to ≤30% for sea freight (IMDG Code SP384) and air freight (IATA). This includes large-format cells (300Ah+) used in China's grid-scale battery manufacturing industry.
- UN3481 — Lithium-ion batteries packed with equipment: Batteries shipped in the same package as the equipment they power, but not installed. Common for power tools with spare batteries, electronic devices with detachable batteries.
- UN3171 — Battery-powered vehicles / equipment: Electric vehicles, e-bikes, electric forklifts, automated guided vehicles (AGVs). The batteries are installed and wired. China is the world's largest EV exporter, making UN3171 a high-volume classification.
Environmentally Hazardous Substances
- UN3077 — Environmentally hazardous substance, solid N.O.S.: Solid materials toxic to aquatic life (acute Category 1, chronic Category 1 or 2 under GHS). Examples: certain pesticides in solid form, heavy metal compounds, some pharmaceutical intermediates. Ships in drums or bags with the "dead fish/dead tree" environmental hazard label.
- UN3082 — Environmentally hazardous substance, liquid N.O.S.: Liquid equivalent of UN3077. Examples: certain industrial chemicals, pesticide formulations, transformer oils containing PCBs, marine anti-fouling paint ingredients.
Other Common Class 9 Substances
- UN1845 — Dry ice (carbon dioxide, solid): Refrigerant for temperature-sensitive cargo. Sublimes at -78.5°C. Package must vent CO2 gas. Most common in air freight for pharmaceutical and food shipments. Less common in sea freight where mechanical reefers are used.
- UN3257 — Elevated temperature liquid: Liquids transported at ≥100°C (or ≥flashpoint for non-Class 3 liquids). Examples: hot bitumen, molten sulfur, heated vegetable oils.
- UN2807 — Magnetized material: Materials with magnetic field strength ≥0.00525 gauss at 4.6 meters from any point on the surface. Only regulated for air freight (IATA DGR). Common in permanent magnets, loudspeakers, and MRI components exported from China's rare earth magnet industry.
- UN2212 — Asbestos (blue/brown): Amphibole asbestos (crocidolite, amosite). Heavily regulated. China banned asbestos mining in 2002 but still exports manufactured asbestos products under strict controls.
- UN2590 — Asbestos (white): Chrysotile (white asbestos). Most common form in commercial use.
- UN3245 — Genetically modified organisms / microorganisms (GMOs/GMMs): Subject to Cartagena Protocol on Biosafety. Documentation must include genetic modification details and risk assessment.
UN3536 / SP389 Deep Dive — Our Core Competency
UN3536 (effective in mandatory IMDG Code from January 2023, Amendment 41-22) was the single most important regulatory change for the containerized energy storage industry. Before UN3536, containerized BESS fell into regulatory gaps — not clearly a standalone battery (UN3480) but not a vehicle (UN3171), forcing shippers and carriers to interpret how to comply. UN3536 and its associated Special Provision 389 (SP389) resolved this ambiguity by creating a dedicated framework.
SP389 key requirements for UN3536 shipments:
- Batteries must be securely installed / mounted in the cargo transport unit (the container itself)
- The BESS design must incorporate protection against overcharge and over-discharge
- Short-circuit protection must be integral to the design, not reliant on external systems
- The unit must be designed to prevent hazardous reverse current flow between parallel strings
- Ventilation must prevent the accumulation of hazardous atmosphere (hydrogen from lead-acid; electrolyte vapor from lithium-ion)
- Batteries must be manufactured under a quality management system (ISO 9001 or equivalent) with documented battery management system (BMS) verification
- No other dangerous goods may be packed in the same unit (segregation from all other DG classes)
Our UN3536 process: Design review (verifying BESS meets SP389 criteria before shipping) → UN38.3 test summary collection (for each cell/battery model in the BESS) → DG packaging certificate (container structure certification) → carrier DG booking (we maintain UN3536 acceptance with MSK, MSC, COSCO, HPL, CMA CGM) → port filing → pre-loading inspection (BMS verification, SoC check, container structural inspection) → loading supervision → voyage monitoring with GPS tracking.
Read our UN3536 case study → | UN3536 shipping guide →
Packaging Requirements by Sub-Category
Lithium Batteries (UN3480, UN3481)
- Cells and batteries must be packed in UN-approved strong outer packaging
- Terminals must be protected against short circuit (insulated caps, recessed design, or individual plastic bags)
- Shock-absorbent cushioning between cells and between cells and outer packaging
- Inner packaging must completely enclose each battery or cell
- Maximum net mass: 30 kg per package for UN3480 (sea freight); stricter limits for air freight
- State of charge limit: ≤30% for UN3480 (IMDG Code SP384). Tested and confirmed by shipper.
UN3536 Containerized BESS
- The container is the packaging — it must meet ISO 1496-1 structural standards and be wind and water tight (CSC plate must be valid)
- DC disconnects and emergency stop must be accessible from outside the container
- Warning labels (Class 9 + UN3536) must be visible on all four sides of the container
- Container must be placarded as DG on all four sides (standard sea freight DG placard, 250mm x 250mm)
- BMS status and SoC must be verified before loading; batteries should ideally be at 30-50% SoC for sea transit
Environmentally Hazardous (UN3077, UN3082)
- Standard UN-approved packaging appropriate to the physical form (liquid/solid)
- Environment hazard label (dead fish/dead tree pictogram) required on packages over 5L/5kg
- Marine Pollutant (P) notation required on the DG declaration and dangerous goods transport document
Dry Ice (UN1845)
- Packaging must allow carbon dioxide gas to vent (never use airtight sealed containers)
- Dry ice quantity must be declared by net weight on the transport document
- For air freight: IATA limits of 200 kg per package on cargo aircraft with operator approval
Carrier Acceptance Table
| Carrier | UN3536 (BESS) | UN3480 (Li-Ion) | UN3481 (Li-Ion w/ Equip) | UN3077/3082 (Env. Haz) | Air Freight |
|---|---|---|---|---|---|
| MSK | Accepted (SP389 verified) | Accepted (adv booking) | Accepted | Accepted | Li-ion limited |
| HPL | Accepted (case-by-case) | Accepted (adv booking) | Accepted | Accepted | Li-ion limited |
| MSC | Accepted | Accepted (adv booking) | Accepted | Accepted | Li-ion limited |
| COSCO | Accepted | Case-by-case | Accepted | Accepted | Not offered |
| HMM | Case-by-case | Restricted | Accepted | Accepted | Not offered |
| OOCL | Case-by-case | Restricted | Accepted | Accepted | Not offered |
| EMC | Not accepted | Restricted | Accepted | Accepted | Not offered |
| YML | Case-by-case | Restricted | Accepted | Accepted | Not offered |
| CMA CGM | Accepted (case-by-case) | Accepted (adv booking) | Accepted | Accepted | Li-ion limited |
UN3480 standalone lithium-ion batteries face increasingly restrictive carrier policies. In 2025-2026, several carriers reduced or suspended UN3480 acceptance on specific routes. UN3536 has better acceptance from major carriers because the installed/integrated nature of BESS with SP389 design safeguards is viewed as lower risk than loose battery shipments. Always confirm current carrier lithium battery policy before booking.
Port Recommendations
Qingdao Port: Our primary UN3536 loading port. Qingdao has become a hub for Chinese BESS exports, with experienced terminal staff who understand SP389 container handling, dedicated DG storage areas suitable for large BESS containers, and the highest carrier acceptance rate among Chinese ports for UN3536. We have shipped 1,000+ TEU of UN3536 cargo from Qingdao.
Shanghai Port: Viable alternative for UN3536 to Europe with wide carrier choice. Larger port means longer terminal queues but higher sailing frequency. Preferred when the destination is Northern Europe and transit time is critical.
Tianjin Port: Used for UN3480/UN3481 lithium battery module exports from battery factories in Hebei and Liaoning.
Documentation Checklist
- MSDS — must identify correct UN number, Class 9 sub-category, and special provisions
- UN38.3 Test Summary (for all lithium cells and batteries) — mandatory from Jan 2026
- BMS Design Verification Report (for UN3536) — confirming SP389 compliance
- State of Charge Declaration (for UN3480) — confirming ≤30% SoC
- Container CSC Plate Copy (for UN3536) — valid structural safety certificate
- DG Packaging Certificate (危包证)
- Maritime DG Declaration
- Port Filing Approval
- Carrier DG Booking Confirmation (with lithium battery / UN3536 acceptance letter)
- Commercial Invoice, Packing List, B/L with DG endorsement
Frequently Asked Questions
Why do you specialize in UN3536? What makes it different from other DG classes?
UN3536 containerized energy storage sits at the intersection of two of the world's fastest-growing industries: renewable energy and battery manufacturing. China produces over 70% of the world's lithium batteries and is the dominant exporter of containerized BESS. The regulatory framework (SP389, IMDG Amendment 41-22) is relatively new, meaning many forwarders and carriers are still building their expertise. We invested early in UN3536 capability — building carrier relationships, developing SP389 compliance audit checklists, training DG inspectors specifically for BESS container verification, and establishing port handling protocols at Qingdao. The result is 1,000+ TEU shipped with zero incidents. For BESS manufacturers, working with a UN3536 specialist forwarder is the difference between smooth sailing and last-minute carrier rejections.
Can UN3480 lithium-ion batteries ship by air freight from China?
It is extremely difficult. Since April 2016, standalone lithium-ion batteries (UN3480) have been prohibited on passenger aircraft under IATA DGR. They may ship on cargo-only aircraft under Section IB (small cells/batteries, max 10 kg gross per package) or Section II (very small cells, max 2.5 kg gross). For the large-format cells (50Ah, 100Ah, 300Ah+) used in grid storage and EVs that China primarily exports, air freight is impractical — these ship exclusively by sea. Air freight is viable only for small consumer-grade cells and batteries. Many Chinese battery exporters overestimate air freight as an option for UN3480 — in practice, more than 98% of UN3480 volume from China moves by sea.
What is the state of charge (SoC) requirement for lithium battery shipments?
IMDG Code Special Provision 384 (effective from 2025, mandatory) limits UN3480 lithium-ion cells and batteries to a maximum 30% state of charge for sea freight. This applies to cells and batteries manufactured after 30 June 2024. For UN3481 (packed with equipment) and UN3536 (installed in BESS containers), different rules apply: there is no strict 30% SoC limit for UN3536, but industry best practice is 30-50% SoC for sea transit to minimize thermal risk while maintaining enough charge to keep the BMS operational for monitoring. The SoC must be declared by the shipper and may be verified by the carrier or port authority. Falsifying SoC declarations is a serious compliance violation.
What documentation is needed for UN3536 BESS shipping specifically?
UN3536 requires a comprehensive documentation package: (1) UN38.3 Test Summary for every cell and battery module in the BESS (mandatory, publicly available from 2026). (2) SP389 Compliance Statement confirming the BESS design meets all SP389 criteria (secure mounting, overcharge/discharge protection, short circuit protection, ventilation, QMS manufacturing). (3) BMS Design Verification Report showing protection parameters and fail-safe modes. (4) State of Charge Declaration (recommended 30-50% SoC). (5) Container CSC Safety Approval Plate copy. (6) DG Packaging Certificate confirming the container structure is suitable for DG transport. (7) Maritime DG Declaration with UN3536, Class 9. (8) Carrier SP389 Acceptance Letter. We prepare and audit this entire package for every UN3536 booking.