{"operation":"document","citation":"25-0021","title":"Currie Associates — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2025-06-26","effective_on":null,"summary":"25-0021 response to Currie Associates concerning 171.7, 173.185.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-25-0021.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-25-0021.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-25-0021","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2025-06/250021.pdf","body":"<<<PAGE 1>>>\n\n1200 New Jersey Avenue, SE\nWashington, DC 20590\nU.S. Department\nof Transportation\nPipeline and Hazardous\nMaterials Safety\nAdministration\nJune 26, 2025\nFrank Lopez\nRegulatory Compliance Specialist\nCurrie Associates\n101 Ridge Street Suite I\nGlens Falls, NY 12801\nReference No. 25-0021\nDear Mr. Lopez:\nThis letter is in response to your February 18, 2025 email requesting clarification of the\nHazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the transportation\nof lithium ion cells and batteries. Specifically, you ask several questions regarding the use of\nfirmware (i.e., the software that controls the hardware of an electronic device) to limit the\nnominal energy expressed as the Watt-hour (Wh) rating of a lithium ion cell or battery contained\nin equipment. You present the following scenarios:\n1. A lithium ion cell is capable of exceeding 20 Wh or a lithium ion battery is capable of\nexceeding 100 Wh, but the cell or battery firmware limits the nominal energy of the cell\nor battery to 20 Wh or 100 Wh, respectively.\n2. A lithium ion cell is capable of exceeding 20 Wh or a lithium ion battery is capable of\nexceeding 100 Wh and is contained in equipment, but the cell or battery firmware limits\nthe nominal energy of the cell or battery to 20 Wh or 100 Wh, respectively.\n3. A lithium ion cell is capable of exceeding 20 Wh or a lithium ion battery is capable of\nexceeding 100 Wh and is contained in equipment, but the equipment’s software limits the\nnominal energy of the cell or battery to 20 Wh or 100 Wh, respectively.\n4. A lithium ion cell is capable of exceeding 20 Wh or a lithium ion battery is capable of\nexceeding 100 Wh and is contained in equipment, but the cell or battery firmware limits\nthe nominal energy of the cell or battery to 20 Wh or 100 Wh. Furthermore, the cell or\nbattery firmware is designed such that the end user can modify the cell or battery voltage\nto full capacity, exceeding 20 Wh or 100 Wh, respectively.\nWe have paraphrased and answered your questions as follows:\nQ1. May the lithium ion cell or battery described in Scenario 1 be shipped in accordance with\nthe smaller lithium ion cell and battery provisions in § 173.185(c)?\n\n<<<PAGE 2>>>\n\nA1. Yes. The United Nations Manual of Tests and Criteria (UNMTC) (incorporated by\nreference, see § 171.7), subsection 38.3.2.3, defines nominal energy or Watt-hour rating\nas “the energy value of a cell or battery determined under specified conditions and\ndeclared by the manufacturer...” Firmware that controls the voltage and ultimately the\nnominal energy is within the design and specified conditions of the lithium ion cell or\nbattery manufacturer. Therefore, the lithium ion cell or battery—as described in Scenario\n1—can be considered a smaller lithium ion cell or battery for transportation.\nQ2. May the lithium ion cell or battery contained in equipment described in Scenario 2 be\nshipped in accordance with the smaller lithium ion cell and battery provisions in\n§ 173.185(c)?\nA2. Yes. See answer A1. The lithium ion cell or battery contained in equipment—as\ndescribed in Scenario 2—can be considered a smaller lithium ion cell or battery for\ntransportation.\nQ3. May the lithium ion cell or battery contained in equipment described in Scenario 3 be\nshipped in accordance with the smaller lithium ion cell and battery provisions in\n§ 173.185(c)?\nA3. No. In Scenario 3, the software that limits the lithium ion cell or battery nominal energy\nto 20 Wh or 100 Wh, respectively, is not inherent to the battery itself. Therefore, the\nlithium ion cell or battery manufacturer’s declared nominal energy value for the lithium\nion cell or battery must be used when determining the applicability of the small lithium\nion cell and battery provisions in § 173.185(c).\nQ4. May the lithium ion cell or battery contained in equipment described in Scenario 4 be\nshipped in accordance with the smaller lithium ion cell and battery provisions in\n§ 173.185(c)?\nA4. Yes. See answer A1. The lithium ion cell or battery contained in equipment—as\ndescribed in Scenario 4—can be considered a smaller lithium ion cell or battery for\ntransportation. However, PHMSA notes that any modification to the lithium ion battery\nfirmware that increases the Wh rating or nominal voltage by 20 percent or more or any\nmodification that represents a change that would lead to failure of any of the tests\nspecified in the UNMTC Section 38.3 (incorporated by reference, see § 171.7),\nconstitutes a new lithium battery type that must be tested prior to any further\ntransportation—see § 173.185(a)(1) and UNMTC 38.3.2.2. In addition, the lithium ion\ncell or battery’s marked Wh rating must be updated to reflect the new, higher Wh rating\nbefore any further transportation in commerce of the lithium ion cell or battery.\nQ5. If the lithium ion cell or battery firmware limits the Wh rating of the cell or battery as\ndescribed in Scenarios 1 through 4, should the cell or battery be marked1 with the Wh\n1 See § 173.185(a)(5).\n\n<<<PAGE 3>>>\n\nrating as limited by the firmware or the maximum possible nominal energy for the cell or\nbattery?\nA5. For Scenarios 1, 2, and 3, the lithium ion cell or battery must be marked with the Wh\nrating determined under the manufacturer’s specified conditions—i.e., as limited by the\nlithium ion cell or battery firmware (note – not the device’s software for Scenario 3). For\nScenario 4, the lithium ion battery must be marked with the Wh rating allowed by the\ncurrently operative firmware before transportation in commerce or as specified in A4, the\nnew, higher Wh rating for the new lithium battery type before any subsequent transport in\ncommerce. Please note that in each scenario, the lithium battery test summary must\nindicate the Wh rating appropriate to the cell or battery. For Scenario 4, this could require\nan update to reflect the higher Wh rating resulting from firmware updates.\nI hope this information is helpful. Please contact us if we can be of further assistance.\nSincerely,\nDirk Der Kinderen\nChief, Standards Development Branch\nStandards and Rulemaking Division\n\n<<<PAGE 4>>>\n\nFebruary 18, 2025\nMr. Shane Kelley\nDirector, Standards and Rulemaking Division\nPipeline and Hazardous Materials Safety Administration\nAttn: PHH-10\nU.S. Department of Transportation\nEast Building, 1200 New Jersey Ave., SE\nWashington, D.C. 20590-0001\nSubmitted: Via Email\ncc: infocntr@dot.gov\nDear Mr. Kelley,\nCurrie Associates would like to request a formal letter of interpretation regarding the standing\ninterpretation of Letter of Interpretation (LOI) No. 22-0113. Specifically, we would like to confirm\nthat the interpretation provided by the LOI, applicable to packaging exceptions based on lithium-\nion battery size, including a battery physically capable of a Watt-hour (Wh) rating of more than\n100 Wh, designed and programmed with firmware (i.e., software for device hardware) that\nprevents the user from charging the lithium ion battery to an energy level that exceeds 100 Wh,\nis considered less than 100 Wh for the purposes of transportation.\nIn the LOI No. 22-0113, PHMSA states “Firmware that controls the voltage and ultimately the\nnominal energy is within the design and specified conditions of the lithium-ion battery\nmanufacturer, following the definition as stated in the United Nations Manual of Tests and\nCriteria.”\nThe United Nations Manual of Tests and Criteria, subsection 38.3.2.3, defines\nWatt-hour rating or nominal energy as “the energy value of a cell or battery determined\nunder specified conditions and declared by the manufacturer….”\nCurrie Associates requests if the interpretation can expand the above scenario to include\nLithium ion batteries contained in equipment? Can a Lithium ion battery or cell contained in\nequipment with a physical battery rating capable of exceeding the Wh requirement, while\ninstalled in a device, be designed and programmed with firmware to limit the energy level Wh to\nmeet requirements and be shipped under the small cell/battery exception?\nExample\nA cell >20 Wh or a battery > 100 Wh, is installed in an electronic device that is designed and\nprogrammed with firmware that will limit the nominal energy to >20 Wh (cell) or a >100 Wh\n(battery) for transport purposes.\nIf permitted, would the required battery case marking display the Watt-hour rating based on the\nfirmware limitations (≤100 Wh) or the actual capacity before the firmware limitations (>100 Wh)?\n101 Ridge Street Suite I, Glens Falls, NY 12801 | Phone: 1-518-761-0668 | mail@currieassociates.com\n\n<<<PAGE 5>>>\n\nAdditionally, If the manufacturer can program the cell/battery to lower the rating of the\ncell/battery for transportation not to exceed 20 Wh/100 Wh, can the manufacturer’s\nprogramming also allow energy levels to be increased by a future firmware update back to the\nfull limit of the cell/battery once it is no longer in the transport chain and in the possession of the\nend user?\nCurrie Associates requests affirmation that LOI 22-0113 is still valid for lithium batteries and\ncells contained in equipment having a physical capability to exceed the small battery exception\nbut be reduced by design and programming to meet the conditions of the exception for\ntransportation. Further, may these programing or physical limitations be removed by firmware\nupdates to permit the full nominal energy?\nWe appreciate your review of this interpretation request and look forward to hearing from you\nsoon.\nSincerely,\nFrank Lopez\nRegulatory Compliance Specialist\nCurrie Associates\nwww.currieassociates.com\nfrank@currieassociates.com\nO: 518-761-0668 Extn. 222","truncated":false,"body_characters":9595}