Lithium Batteries Identification & Classification (UN 3090, 3091, 3480, 3481)

Lithium Batteries Identification & Classification (UN 3090, 3091, 3480, 3481)

Due to their high energy density and risk of thermal runaway, lithium batteries represent one of the most highly scrutinized categories of dangerous goods in commercial aviation. A thermal runaway event in a single cell can generate intense heat, toxic gases, and flammable vapor, potentially leading to uncontrollable fire in an aircraft cargo compartment. Consequently, the IATA DGR enforces rigid rules regarding UN identification, chemistry distinction, energy thresholds, packaging sections, State of Charge (SoC) restrictions, and passenger aircraft bans.

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1. The Four Core UN Numbers for Lithium Batteries

Lithium batteries are classified into four separate UN entries based on their chemical composition (Lithium Ion vs. Lithium Metal) and packaging configuration (standalone vs. packed with/contained in equipment):

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2. Chemical Distinction & Technical Energy Thresholds

Regulations differentiate between rechargeable Lithium Ion (which utilize intercalated lithium compounds) and non-rechargeable Lithium Metal (which contain metallic lithium). Regulatory compliance paths depend on energy rating thresholds:

                                  +------------------------------------+ 
                                  |    Lithium Battery Thresholds      | 
                                  +------------------------------------+ 
                                                    | 
       +--------------------------------------------+--------------------------------------------+ 
       |                                                                                         | 
       v                                                                                         v 
+------------------------------------+                                     +------------------------------------+ 
|  Lithium Ion (Rechargeable)        |                                     |  Lithium Metal (Non-Rechargeable)  | 
|  - Cell: <= 20 Watt-hours (Wh)     |                                     |  - Cell: <= 1.0 g Lithium Content  | 
|  - Battery: <= 100 Watt-hours (Wh) |                                     |  - Battery: <= 2.0 g Li Content    | 
+------------------------------------+                                     +------------------------------------+ 
       |                                                                                         | 
       v                                                                                         v 
+------------------------------------+                                     +------------------------------------+ 
| Qualifies for Section IB / II      |                                     | Qualifies for Section IB / II      | 
| Reduced Packaging Provisions       |                                     | Reduced Packaging Provisions       | 
+------------------------------------+                                     +------------------------------------+ 

• Large / High-Capacity Batteries (Exceeding Thresholds): Any Li-ion cell above 20 Wh, Li-ion battery above 100 Wh, Li-metal cell above 1 g, or Li-metal battery above 2 g is fully regulated Class 9 dangerous goods. Shipped alone, it goes under Section IA of PI 965 (lithium ion) or PI 968 (lithium metal). Shipped with or in equipment, it goes under Section I of PI 966, 967, 969 or 970 — those four packing instructions have only a Section I and a Section II, never a Section IA or IB.

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3. Packaging Sections: Section IA vs. Section IB vs. Section II

The single most important structural fact: the sections available to you depend on which packing instruction applies.

Section II was deleted from PI 965 and PI 968. The change took effect with the 63rd edition (1 January 2022), with a transition that ended on 31 March 2022. Since then, every standalone lithium ion or lithium metal consignment — however small the cells — must be prepared under Section IA or Section IB, which means a Shipper's Declaration, the Class 9 lithium battery hazard label, and the Cargo Aircraft Only label. Any study material or checklist still offering a "Section II" route for UN 3480 or UN 3090 is out of date, and quoting it is an automatic fail on an acceptance check.

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4. Standalone Battery Bans & Cargo Aircraft Only (CAO) Rules

To mitigate severe fire hazards in flight, international regulations enforce strict operational prohibitions on standalone lithium batteries:

Passenger Aircraft Ban on Standalone Batteries

• UN 3480 (Standalone Lithium Ion) and UN 3090 (Standalone Lithium Metal) are STRICTLY FORBIDDEN from transport on passenger aircraft.
• Standalone lithium batteries MUST be shipped on Cargo Aircraft Only (CAO) and bear the Cargo Aircraft Only label.
• Exception: Lithium batteries packed with equipment (UN 3481 / UN 3091) or contained in equipment (UN 3481 / UN 3091) ARE permitted on passenger aircraft provided the packing instruction limits are satisfied.
• Because Section II no longer exists for PI 965 and PI 968, every standalone consignment now carries the Class 9 lithium battery label, the lithium battery mark (Section IB), the Cargo Aircraft Only label, and a Shipper's Declaration.

Mandatory 30% State of Charge (SoC) Restriction

Under DGR Packing Instruction 965 (both Section IA and Section IB), standalone lithium ion cells and batteries (UN 3480) offered for air transport must be shipped at a State of Charge (SoC) not exceeding 30% of their rated design capacity.

• Testing has proven that keeping SoC at or below 30% significantly reduces the likelihood of thermal propagation between adjacent cells in the event of an internal short circuit.
• Shipping UN 3480 above 30% SoC requires explicit approval from the State of Origin and the State of the Operator.