UN 3091 vs UN 3090: Choosing The Right UN Number

UN 3091 Marking is the UN identification marking for lithium metal batteries packed with or contained in equipment.

Selecting between UN 3091 and UN 3090 is one of the most common classification decisions shippers face when dealing with non-rechargeable lithium metal batteries. The difference hinges on whether the battery is shipped alone or with/inside equipment. Correct selection affects packing instructions, permitted modes of transport, quantity limits, and required documentation — so getting it right prevents non-compliance, delays, and safety risks.

Key Differences

• Primary distinction: UN 3090 is for lithium metal cells and batteries transported by themselves. UN 3091 is for those packed with or contained in equipment.
• Packing rules: Each UN number references different packing instructions in modal regulations (e.g., IATA/ICAO, IMDG, 49 CFR). These instructions set testing, packaging, and quantity limits.
• Labeling and marking: Packages under UN 3090 and UN 3091 require distinct UN markings. UN 3091 uses the UN number that clearly indicates the batteries are packed with/contained in equipment.

How The Choice Affects Shipping Options

Mode restrictions and allowed quantities can differ. For example, air transport rules (IATA/ICAO) set specific provisions for batteries packed with equipment that may allow larger gross weights per package in some limited cases, or impose special packaging requirements to minimize activation or damage during carriage. Road and sea rules (49 CFR and IMDG) similarly reference the applicable UN number when assigning packing instructions.

How To Decide — Practical Steps

• Step 1 — Identify the article: Is the battery shipped loose (e.g., bulk cells), or is it installed in a device or packed together in the same package with a device? If installed or packed with equipment, lean toward UN 3091.
• Step 2 — Consult regulations: Check the modal packing instructions (IATA/ICAO for air, IMDG for sea, 49 CFR for road/US domestic) for the exact requirements and exceptions tied to UN 3090 vs UN 3091.
• Step 3 — Apply tests and limits: Verify whether the battery and packaging combination meets required testing and quantity limits for the chosen UN number.

Common Misclassification Traps

Several recurring errors generate compliance problems:

• Assuming installed equals packed: Batteries installed in equipment are UN 3091, but batteries loosely packed in the same outer box with equipment (not installed) may still fall under UN 3091 — classification depends on regulatory definitions and packing arrangement.
• Ignoring state/airline variations: Some countries or carriers impose stricter limits than international standards — always check carrier and state requirements for lithium batteries.
• Overlooking documentation: Even when UN 3091 applies, required documentation varies by mode. Not providing the correct paperwork is a common cause for rejected shipments.

Operational Example

A supplier ships handheld gas detectors with a non-rechargeable lithium metal cell installed. Because the batteries are part of the equipment, the shipment is classified under UN 3091. The shipper uses the packing instruction that applies to lithium metal batteries packed with equipment, marks the outer package with UN 3091, includes the appropriate dangerous goods statement, and follows any airline-specific procedures for acceptance.

Checklist For Teams Making The Call

• Identify whether the battery is loose or with/inside equipment.
• Confirm chemistry (lithium metal vs lithium-ion) to select the correct UN family.
• Check applicable packing instruction and quantity limits for the chosen UN number.
• Apply the correct marking and include required documentation at tendering.
• Verify carrier and state-specific restrictions before booking.

In short, the UN 3091 Marking is used when lithium metal batteries are packed with or contained in equipment; choosing between UN 3090 and UN 3091 drives the applicable packing instructions, labeling, and acceptance conditions that keep shipments compliant and safe.