UN 3090 Vs UN 3091: How Markings And Packaging Differ

UN 3090 Marking The UN identification marking for lithium metal batteries shipped by themselves. Understanding how that marking differs from other lithium battery UN numbers—particularly UN 3091 (lithium metal batteries contained in equipment or packed with equipment)—is essential for correct classification and compliance.

At a glance, UN 3090 applies to batteries offered for transport as standalone units, while UN 3091 applies when batteries are packed inside, with, or contained in equipment (for example, a battery in a hand tool or spare batteries inside the same package as the device). The regulatory differences affect the required marking, documentation, packing instructions, and sometimes the maximum quantity per package.

Key Regulatory Distinction

The UN number determines which packing instruction from the applicable regulations applies. For UN 3090 shipments, packers must follow packing instruction language specific to standalone batteries, which often has stricter rules for preventing short circuits, thermal protection, and the use of inner packaging. UN 3091 packing instructions recognize that batteries are associated with equipment, and allow different stowage or quantity allowances in some modes.

Marking Differences

Both UN 3090 and UN 3091 require the UN number to appear on the package where the regulations call for it, but the accompanying text and marks differ:

• UN Number Text: UN 3090 must be visible on the outer packaging as "UN 3090"; UN 3091 packages must show "UN 3091" when applicable.
• Lithium Battery Mark: The standard lithium battery handling mark is used with both UN numbers in many jurisdictions, but the format and required adjacent text (for example, "Lithium metal batteries" versus "Lithium metal batteries contained in equipment") should match the UN entry and packing instruction.
• Supplementary Information: Packages containing lithium batteries shipped by themselves may need additional details (e.g., state of charge, number of cells, net explosive substance limit statements, or emergency contact phone numbers) that differ from those required for batteries in equipment.

Practical Operational Differences

In practical warehouse and transport operations, the distinction matters for labeling, documentation, and carrier acceptance:

• Packing Materials: Standalone cells often require more robust internal separation and insulation to prevent movement and contact than batteries already installed in equipment.
• Quantity Limits: Air and surface rules can impose lower per-package limits for standalone lithium metal batteries (UN 3090) than for batteries packed with equipment (UN 3091).
• Carrier Policies: Some carriers restrict or prohibit UN 3090 shipments by passenger aircraft, while allowing UN 3091 in limited quantities if properly packaged.

Documentation And Declarations

Both UN numbers require a dangerous goods declaration when transported by air or when other modal rules require it, but the content differs. For UN 3090, declarations must reference the packing instruction number for standalone lithium metal batteries and include the UN number text. Air shipments usually require an additional statement on the shipper's declaration and, frequently, the emergency contact phone number and a description of the battery type (primary versus rechargeable).

Examples That Illustrate The Difference

Example A — Spare Batteries (UN 3090): A parcel contains five loose lithium metal cells. The shipper must classify the parcel as UN 3090, apply the UN 3090 marking and handling mark, follow the packing instruction for standalone cells, and include the required documentation and emergency contact.

Example B — Battery In Device (UN 3091): A parcel contains a handheld GPS device with a non-replaceable lithium metal battery installed. This shipment is typically UN 3091 (contained in equipment). The package gets marked with "UN 3091" as needed, may follow a different packing instruction, and might qualify for more lenient quantity limits or packaging provisions depending on mode.

How To Avoid Misclassification

• Verify Physical State: Confirm whether batteries are loose (UN 3090) or installed/packed with equipment (UN 3091).
• Check Manufacturer Specs: Use the battery datasheet and UN test reports to confirm battery chemistry and to determine if tests were performed for the applicable UN entry.
• Consult Regulations: Match the shipment to the correct packing instruction in 49 CFR, ICAO, IMDG, or other applicable modal rules before marking and offering freight.

In short, the UN 3090 Marking marks packages of lithium metal batteries shipped by themselves; it differs from the UN 3091 marking in intended contents, required packing instructions, allowed quantities, and documentation. Correctly distinguishing between UN 3090 and UN 3091 at the point of packing avoids carrier refusals and regulatory non‑compliance.