UN3480 lithium ion batteries decoder.

The UN3480 row in the Hazardous Materials Table

The table below is 49 CFR 172.101 as published in the eCFR, current through October 29, 2026, for UN3480. Columns are: class (3), packing group (5), label codes (6), special provisions (7), packaging exceptions (8A), non-bulk packaging (8B), bulk packaging (8C), quantity limits for passenger aircraft or railcar (9A) and cargo aircraft only (9B), and vessel stowage (10A and 10B). There is one row.

Reading the packaging columns

Columns 8A to 8C do not hold rules themselves; they point to sections of part 173. For this entry they point to:

• 173.185: Lithium cells and batteries.

Exceptions in column 8A apply only if that section is referenced for the specific material in the table, so a limited quantity route that exists for one UN number is not automatically open to another.

Special provisions on this entry

The letter prefixes on special provisions tell you where each applies (172.102(c)): a code of only numbers is multi-modal; "A" applies only to transportation by aircraft; "B" only to bulk packaging; "IB" and "IP" only to IBCs; "N" only to non-bulk packaging; "T" and "TP" only to UN portable tanks.

• 388: Sets conditions for batteries that combine primary lithium metal cells and rechargeable lithium ion cells that are not designed to be externally charged; such batteries are assigned to UN3090 or UN3091.
• 422: When labelling is required the label is the one in 172.447; when a placard is displayed it is the placard in 172.560.
• A54: Irrespective of the column 9B quantity limits, a lithium battery that otherwise meets 173.185 may exceed 35 kg if approved by the Associate Administrator before shipment.
• A100: Lithium ion cells and batteries must be offered at a state of charge not exceeding 30 percent of rated capacity; above that they may be transported only under conditions approved by the Associate Administrator under 49 CFR part 107, subpart H.

Why UN3480 is not UN3481

UN3480 covers lithium ion batteries shipped on their own. The table has separate entries for batteries contained in equipment and batteries packed with equipment, both under UN3481. The contained-in-equipment entry shows a passenger aircraft limit of 5 kg and a cargo aircraft limit of 35 kg, so a laptop with its battery installed is treated differently from a loose spare battery. Picking the wrong UN number is the most common reason a lithium shipment is rejected, because the packing, quantity and aircraft rules all key off it.

The entry lists special provisions 388, 422, A54 and A100. Provision 388 sets conditions for batteries that combine primary lithium metal cells and rechargeable lithium ion cells not designed to be externally charged. Provision 422 says the label is the one in 172.447 and the placard, if displayed, is the one in 172.560. Provision A54 lets a battery exceed 35 kg on a cargo aircraft only if the Associate Administrator approves it before shipment.

The 30 percent state of charge rule (A100)

Special provision A100 says lithium ion cells and batteries must be offered for transport at a state of charge not exceeding 30 percent of rated capacity. Above 30 percent they may travel only under conditions approved by the Associate Administrator under 49 CFR part 107, subpart H. The provision points to sub-section 38.3.2.3 of the UN Manual of Tests and Criteria for the way to determine rated capacity. Under 172.102(c), a code containing the letter A refers to a provision that applies only to transportation by aircraft, so A100 and A54 are air conditions in the table. A ground-only shipper should not read A100 as a highway rule, and an air shipper should record how the charge level was set.

What 173.185 requires before the exceptions

Every lithium cell or battery must be a type proven to meet sub-section 38.3 of the UN Manual of Tests and Criteria. The manufacturer must keep a record of the testing for as long as the design is offered for transport and one year after, and manufacturers and later distributors must make a test summary available. Each lithium ion battery must be marked with its Watt-hour rating on the outside case from May 10, 2024. Packages go in non-metallic inner packagings that fully enclose the cells or batteries, then in a Packing Group II level box, drum or jerrican.

Large batteries get a lighter packaging route: those weighing 12 kg (26.5 pounds) or more with a strong, impact-resistant casing may travel in strong outer packagings, protective enclosures or on pallets, and cargo aircraft carriage then needs approval from the Associate Administrator.

Smaller batteries: the 173.185(c) size limits

Paragraph (c) excepts smaller cells and batteries from subparts C through H of part 172 and from the UN performance packaging requirements, if the size limits are met: not over 20 Wh per lithium ion cell and not over 100 Wh per lithium ion battery. For highway or rail only, the limits rise to 60 Wh per cell and 300 Wh per battery, provided the outer package is marked LITHIUM BATTERIES—FORBIDDEN FOR TRANSPORT ABOARD AIRCRAFT AND VESSEL. Packages not over 30 kg gross weight, unless packed with or contained in equipment. The checker above applies those four numbers to the rating you enter; the other paragraph (c) conditions, such as the lithium battery mark and the package marking, still have to be met.

ERG 2024 Guide 147: Lithium Ion and Sodium Ion Batteries

The ERG 2024 numerical index lists UN3480 against Guide 147. The guide appears on pages 223 to 224 of the 2024 guidebook. The guidebook is meant for first responders during the initial phase of an incident, and it says to call 911 and then the emergency response telephone number on the shipping paper.

• Fire or explosion: the batteries contain flammable liquid electrolyte that may vent, ignite and produce sparks at high temperature (above 150 degrees C / 302 degrees F) or when damaged or abused. They may burn rapidly with a flare-burning effect and may ignite other batteries in close proximity.
• Health: contact with battery electrolyte may irritate skin, eyes and mucous membranes, and burning batteries may produce toxic hydrogen fluoride gas (the guide points to Guide 125).
• Evacuation: isolate a spill or leak area for at least 25 meters (75 feet) in all directions; if a rail car or trailer is involved in a fire, isolate and evacuate for 500 meters (1/3 mile) in all directions.
• Fire response: a lithium ion or sodium ion battery fire may reignite at any point after the initial fire is extinguished, up to weeks later. The guide recommends thermal imaging to monitor the battery and cautions that salt water is not recommended because it may increase production of hydrogen and hydrogen fluoride gas.
• Small fire (for example personal electronic devices or an e-bike): water spray only, in large amounts, and not dry chemical, CO2 or Halon. Large fire: allow the battery fire to burn itself out and protect surroundings, apply water spray to neighboring batteries.

The guide is a starting point until the material is identified. Read the full guide in the current ERG, and use the shipping paper emergency number for product-specific advice.

Placards, quantity and vessel stowage

Class 9 is a Table 2 category, but 172.504(f)(9) says a CLASS 9 placard is not required for domestic transportation, including the part of international transportation that occurs within the United States. A bulk packaging must still be marked with the identification number on a CLASS 9 placard, an orange panel or a white square-on-point display.

Vessel stowage is the category in column 10A (A), which the table sets for this entry, plus the column 10B codes. Hazmat shipped as a limited quantity is allocated stowage category A and is not subject to the column 10B stowage codes (176.63(a)).

• 156: For lithium batteries transported in accordance with 173.185(f) or for disposal or recycling, stowage category C applies.

Worked example

A courier moves 12 identical 74 Wh e-bike batteries by highway. 74 Wh is under the 100 Wh battery limit, so the 173.185(c)(1)(i) size test is met. If the same pack were 250 Wh, it would exceed 100 Wh, but a highway or rail only shipment would still fall under the 300 Wh limit in (c)(1)(iv), with the FORBIDDEN FOR TRANSPORT ABOARD AIRCRAFT AND VESSEL marking. A 250 Wh pack going by air is outside paragraph (c) and moves as full UN3480: forbidden on passenger aircraft, at most 35 kg net per package on cargo aircraft only, offered at not more than 30 percent state of charge (A100).

Limits

This page reads the 172.101 table, the 172.102 special provisions, 172.504 and the section titles named above, plus ERG 2024. It does not classify your material, choose a proper shipping name, or build shipping papers, marks, labels or training requirements. The checker compares your net quantity to the printed column 9A and 9B limits and applies the 1,001 pound rule to the class on the row; it does not model subsidiary hazard placards (172.505), mixed loads, state rules or carrier restrictions. Special provisions are shown in summary; read the full text in 172.102 before relying on one. Hazmat shipping needs trained hazmat employees (49 CFR part 172, subpart H).

Sources

Sources opened and read November 2, 2026.

• eCFR: 49 CFR 172.101, Hazardous Materials Table (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 172.102, special provisions (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 172.504, general placarding requirements (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 173.185, Lithium cells and batteries (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 176.84, other requirements for stowage, cargo handling and segregation (current through October 29, 2026) (read November 2, 2026)
• eCFR: 49 CFR 176.63, stowage locations (current through October 29, 2026) (read November 2, 2026)
• PHMSA: Emergency Response Guidebook (ERG) landing page (read November 2, 2026)
• PHMSA: ERG 2024 PDF, numerical index and guide pages (the phmsa.dot.gov host refused automated requests; the Internet Archive copy of this file was read) (read November 2, 2026)