Under 49 CFR 173.185, the lithium battery shipping requirements are straightforward in structure even when the details get thick: every cell and battery design must pass UN 38.3 testing, ship in packaging that prevents short circuits and movement, and carry the right UN identification number, markings, and — above the small-battery thresholds — a Class 9 label and hazmat shipping paper. The rule covers lithium ion and lithium metal batteries whether shipped alone, packed with equipment, or installed in a device, and it is enforced by the Pipeline and Hazardous Materials Safety Administration (PHMSA). Civil penalties can exceed $100,000 per violation.
UN 38.3 Testing and the Test Summary
No lithium cell or battery design may enter the U.S. transportation system unless it has passed the eight safety tests in the UN Manual of Tests and Criteria, Part III, Sub-section 38.3.1eCFR. 49 CFR 173.185 – Lithium Cells and Batteries The battery must pass as assembled, not only as individual cells. A failed design cannot ship under normal conditions.
For any cell or battery manufactured on or after January 1, 2008, the manufacturer and every subsequent distributor must make a test summary available. Button cells installed in equipment are the only exception. The summary must identify the manufacturer, the testing laboratory, a unique test report number, the date of the report, the cell or battery’s physical description including watt-hour rating or lithium content, the list of tests conducted with pass/fail results, and a responsible person who vouches for the information.2Pipeline and Hazardous Materials Safety Administration. Lithium Battery Test Summaries If you are a distributor or shipper, get this document from your manufacturer before you ship. It won’t be handed to you automatically.
Small-Battery Exceptions: Which Path You Are On
The first practical question in any lithium shipment is whether the batteries qualify for the small-battery exceptions in Section 173.185(c). If they do, you skip UN-specification performance packaging and most of the Part 172 hazmat paperwork. If they don’t, you are in fully regulated territory.
To qualify, cells and batteries must fall within these limits:3eCFR. 49 CFR 173.185 – Lithium Cells and Batteries
- Lithium ion: no more than 20 Wh per cell or 100 Wh per battery, with the watt-hour rating marked on the outside case.
- Lithium metal: no more than 1 gram of lithium per cell or 2 grams per battery.
- Package weight: standalone battery packages cannot exceed 30 kg (66 pounds) gross weight.
Most consumer electronics batteries — phones, laptops, cameras, power tools — sit inside these thresholds. Industrial batteries, EV modules, and stationary storage systems typically do not.
There is a higher-limit pathway for shipments moving exclusively by highway or rail: up to 5 grams per lithium metal cell (25 grams per battery) and 60 Wh per lithium ion cell (300 Wh per battery). The package must be marked “LITHIUM BATTERIES—FORBIDDEN FOR TRANSPORT ABOARD AIRCRAFT AND VESSEL.” Useful for mid-size batteries that don’t need to fly.
Packaging Requirements
The point of every packaging rule in this section is the same: keep cells from short-circuiting each other or contacting conductive material, and keep them from shifting in transit. What changes is how demanding the container has to be.
Exception-Level Packaging
Batteries shipped under the small-battery exceptions must sit in inner packagings that completely enclose each cell or battery, and then in a strong, rigid outer package. The finished package must survive a 1.2-meter drop in any orientation without damaging the batteries, allowing them to shift into contact, or releasing contents.1eCFR. 49 CFR 173.185 – Lithium Cells and Batteries A retail box is unlikely to meet that standard.
Fully Regulated Packaging
Above the thresholds, you need UN-specification packaging tested to Packing Group II. Each battery goes into a non-metallic inner packaging that completely encloses it and prevents contact with conductive materials. Acceptable outer containers include metal, wooden, fiberboard, or solid plastic boxes; metal, plywood, fiber, or plastic drums; and metal or plastic jerricans meeting Part 178 performance standards.
When batteries are packed with equipment (rather than installed), you either put the batteries into a Packing Group II container and then into a strong outer package with the equipment, or put the batteries and the equipment together into a single Packing Group II container. For air transport, package quantity is capped at what is needed to power the equipment plus two spare sets.
Batteries Contained in Equipment
Batteries already installed in a device get slightly relaxed outer-packaging rules because the device itself provides some protection. The equipment must be secured against shifting, and the packaging must prevent accidental activation in transit. Any spare batteries in the same package still meet the full inner-packaging enclosure rules.
The Four UN Numbers
The Hazardous Materials Table in 49 CFR 172.101 assigns four UN identification numbers to lithium batteries, split by chemistry and packing method:4eCFR. 49 CFR 172.101 – Purpose and Use of Hazardous Materials Table
- UN3480: lithium ion batteries shipped on their own.
- UN3481: lithium ion batteries packed with equipment or contained in equipment.
- UN3090: lithium metal batteries shipped on their own.
- UN3091: lithium metal batteries packed with equipment or contained in equipment.
Picking the wrong number is one of the most common ways to get a shipment rejected. A laptop with its battery installed ships as UN3481. A box of loose replacement cells ships as UN3480. A phone battery taped to the outside of a phone box is “packed with” equipment; a battery inside the phone is “contained in” equipment. Both are UN3481, but the packaging expectations differ.
Markings and Labels
What appears on the outside of the package depends on the battery size, how it’s packed, and how it’s traveling.
Packages shipped under the small-battery exceptions must display the Lithium Battery Mark, which includes the applicable UN number and a phone number for additional information, against a contrasting background. Unless the batteries are packed with or contained in equipment and weigh 5 kg or less net, exception-level packages of standalone cells or batteries must also carry a marking stating they are forbidden aboard passenger aircraft, or a “CARGO AIRCRAFT ONLY” label. New shippers often miss this one, assuming the small-battery exception strips all hazmat labels. It does not.
Fully regulated shipments require the Class 9 miscellaneous hazardous materials label — a white diamond with black vertical bars at the bottom.
When multiple lithium battery packages ride together in an overpack, all required markings must either be visible through the overpack or reproduced on its outside, and the overpack itself must be labeled “OVERPACK” in lettering at least 12 mm high if the inner markings are hidden.5eCFR. 49 CFR 173.25 – Authorized Packagings and Overpacks
Shipping Papers
Fully regulated shipments require a shipping paper listing the proper shipping name, the hazard class (Class 9), the correct UN number, and the packing group if one applies. The paper must also carry a 24-hour emergency response telephone number that connects to someone who can give immediate technical guidance about the shipment. An answering machine or general customer service line will not satisfy that requirement.
Shipments qualifying for the small-battery exceptions are largely excused from the Part 172 shipping paper requirements in Subparts C through H. That is one of the biggest practical benefits of staying under the thresholds. Carrier-specific paperwork is a separate matter and can go beyond the federal minimum.
Air Transport
Air is where the rules tighten hardest. Standalone lithium ion and lithium metal batteries (UN3480 and UN3090) are generally forbidden on passenger aircraft and must travel on cargo-only aircraft. Batteries packed with or contained in equipment can fly on passenger aircraft only if the total net weight of lithium cells and batteries in the package does not exceed 5 kg and the package holds only enough to power the equipment plus two spare sets. A narrow carve-out allows replacement lithium cells or batteries for medical devices to travel as cargo on passenger aircraft when approved by PHMSA’s Associate Administrator and the destination is not served daily by cargo aircraft.
Lithium ion batteries shipped by air are also subject to the state-of-charge limitation in special provision A100 of 49 CFR 172.102. Medical device batteries are exempted from that restriction if individually packed in inner packaging, placed in a rigid outer package, and protected against short circuits.
Whenever hazardous materials are loaded on an aircraft, the operator must give the pilot-in-command a written notice before the aircraft moves under its own power.6eCFR. 49 CFR 175.33 – Notification of Pilot in Command The notice must include the proper shipping name and UN number, total number of packages, exact loading location, net quantity or gross mass of each package, cargo-only-aircraft status if applicable, and the destination airport. A monitored phone number must be reachable during flight.
USPS layers its own rule on top: pre-owned, damaged, or defective electronic devices containing lithium batteries can only be mailed by surface transportation — USPS Retail Ground, Parcel Select, Parcel Return Service, or Ground Return Service.7United States Postal Service. Publication 52 Revision – Required Hazardous Materials Separations Returning a defective phone or laptop through the mail is surface-only.
Damaged, Defective, or Recalled Batteries
Batteries that are damaged, identified by the manufacturer as defective for safety reasons, or capable of producing dangerous heat, fire, or a short circuit cannot fly under any circumstances. They ship only by highway, rail, or vessel.
The packaging rules jump. Each cell or battery goes individually into a non-metallic inner packaging that completely encloses it. That inner packaging must be surrounded by cushioning that is non-combustible, electrically non-conductive, and absorbent. The whole thing goes into an outer container meeting Packing Group I standards — the tier used for the most dangerous goods. Acceptable outer containers include metal, wooden, or solid plastic boxes and metal, plywood, or plastic drums. The outside of the package must be marked “Damaged/defective lithium ion battery” or “Damaged/defective lithium metal battery” in characters at least 12 mm high.
A swollen phone battery in a plain cardboard box is not only illegal, it is genuinely dangerous.
Hazmat Employee Training
Anyone who handles, packages, signs shipping papers for, or loads lithium battery shipments is a hazmat employee under federal law and must be trained before doing any of that work. Training covers general awareness of the Hazardous Materials Regulations, function-specific instruction tied to the person’s actual duties, safety and emergency response, security awareness, and — only if the employer maintains a security plan — in-depth security.8Pipeline and Hazardous Materials Safety Administration. Hazardous Materials Training Requirements
Employees must demonstrate competence through written, oral, or practical testing. Training renews at least every three years.9eCFR. 49 CFR 172.704 – Training Requirements Employers must keep records for each hazmat employee for the length of that person’s hazmat role plus 90 days after they leave it. A warehouse worker who has been sealing lithium battery boxes for years with no documented training is an enforcement liability on every shipment.
Incident Reporting
When something goes wrong in transit, a written incident report on DOT Form F 5800.1 must be filed within 30 days of discovery if any of the following happens:10eCFR. 49 CFR 171.16 – Detailed Hazardous Materials Incident Reports
- A person is killed.
- A person is hospitalized.
- The public is evacuated for one hour or more.
- A major transportation route or facility is shut down for one hour or more.
- An aircraft’s flight pattern is altered.
- Fire, breakage, or spillage occurs involving the shipment.
- Any release of hazardous material occurs, or a situation exists that should be reported even without meeting the other criteria.
For lithium batteries specifically, fire and smoke events are the most common triggers. A cell that starts venting or heating in a cargo hold qualifies even if no one is hurt and nothing else burns. The person in physical possession of the material at the time bears the reporting obligation.
Penalties
Civil penalties for a knowing violation of the hazardous materials transportation law reach $102,348 per violation. If a violation causes death, serious illness, severe injury, or substantial property destruction, the ceiling rises to $238,809.11Federal Register. Revisions to Civil Penalty Amounts, 2025 Both figures adjust annually for inflation.
Criminal penalties apply when a violation is willful or reckless: a fine under Title 18 and up to five years in prison. If the violation involves a release of hazardous material that causes death or bodily injury, the maximum imprisonment doubles to ten years.12Office of the Law Revision Counsel. 49 USC 5124 – Criminal Penalty A paperwork violation alone, even a serious one, sits at the five-year ceiling. The ten-year exposure requires an actual release that harms someone.