{"operation":"document","citation":"23-0100","title":"Eos Energy Enterprises Inc. — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2023-11-17","effective_on":null,"summary":"23-0100 response to Eos Energy Enterprises Inc. concerning 171.22, 171.23, 171.24, 171.8.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-23-0100.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-23-0100.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-23-0100","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2025-12/230100.pdf","body":"<<>>\n\nU.S. Department\nof Transportation\nPipeline and Hazardous\nMaterials Safety\nAdministration\n1200 New Jersey Avenue, SE\nWashington, DC 20590\nNovember 17, 2023\nDenielle Gower\nDirector of Logistics\nEos Energy Enterprises Inc\n3920 Park Ave\nEdison, NJ 08820\nReference No. 23-0100\nDear Ms. Gower:\nThis letter is in response to your October 31, 2023 email and subsequent phone conversations\nrequesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180)\napplicable to the classification of batteries and battery storage systems containing zinc bromide.\nSpecifically, you are seeking confirmation that these batteries, when shipped at a zero state of\ncharge and containing no other materials meeting the definition of a hazardous material other\nthan zinc bromide, may be classed as “UN3548, Articles containing miscellaneous dangerous\ngoods, n.o.s., (zinc bromide), 9.”\nBased on the information you have provided in your email and subsequent phone conversations;\nit is the opinion of this Office that “UN3548, Articles containing miscellaneous dangerous\ngoods, n.o.s., (zinc bromide), 9” is an appropriate shipping description for the batteries and/or\nbattery assembly you describe. While your email references the IATA DGR, please note that the\nHMR do not officially recognize the IATA DGR for purposes of transporting hazardous\nmaterials. However, § 171.22 of the HMR authorizes use of the International Civil Aviation\nOrganization’s (ICAO) Technical Instructions for the Safe Transport of Dangerous Goods by\nAir (Technical Instructions) provided shipments offered under the ICAO Technical Instructions\nconform to the applicable requirements of §§ 171.23 and 171.24. The ICAO Technical\nInstructions list special provision A224 with this entry along with A2. Special Provision A224\nstates that articles containing miscellaneous dangerous goods, n.o.s. may be transported on\npassenger and cargo aircraft irrespective of the indication of “forbidden” in columns 10 to 13 of\nTable 3-1, provided that the only dangerous goods contained in the article is an environmentally\nhazardous substance, the articles are packed in accordance with Packing Instruction 975, and\nreference to Special Provision A224 is made on the dangerous goods transport document. Zinc\nbromide meets the criteria for an environmentally hazardous substance but does not meet the\ncriteria for inclusion in any other hazard class. Therefore, Special Provision A224 would apply,\n\n<<>>\n\nand these articles would not be forbidden. Please note, in accordance with § 171.23(b)(5), these\narticles may be subject to additional requirements for hazardous substances as defined in § 171.8.\nI hope this information is helpful. Please contact us if we can be of further assistance.\nSincerely,\nShane C. Kelley\nDirector\nStandards and Rulemaking Division\nOffice of Hazardous Materials Safety\n\n<<>>\n\nLarson, R.\n23-0100\nFrom: Andrews, Steven (PHMSA)\nTo: Larson, Ryan (PHMSA)\nSubject: FW: Request an Opinion for Eos Energy Storage System\nDate: Tuesday, October 31, 2023 3:27:59 PM\nAttachments: image001.png\nimage003.png\nimage001.png\nHey Ryan,\nThink you have time tomorrow/Thursday to look into this for us?\nThanks\nSteven\nFrom: Kelley, Shane (PHMSA) \nSent: Tuesday, October 31, 2023 1:04 PM\nTo: DerKinderen, Dirk (PHMSA) ; Andrews, Steven (PHMSA)\n\nCc: Nickels, Matthew (PHMSA) ; Webb, Steven (PHMSA)\n\nSubject: Fwd: Request an Opinion for Eos Energy Storage System\nDirk/Steven\nCould someone on the team take a look and offer thoughts on classification under the HMR and\nICAO?\nFrom: Denielle Gower \nSent: Tuesday, October 31, 2023 12:15:07 PM\nTo: Vierling, Ryan (PHMSA) ; Falat, Lad (PHMSA) ;\nBurger, Donald (PHMSA) ; Kelley, Shane (PHMSA)\n; Klem, Michael (PHMSA) \nCc: Nicks, Michael (PHMSA) ; Rene Sotolongo \nSubject: Request an Opinion for Eos Energy Storage System\nCAUTION: This email originated from outside of the Department of Transportation (DOT). Do\nnot click on links or open attachments unless you recognize the sender and know the content\nis safe.\nTo whom it may concern,\nAs per our last conversation we are formally requesting guidance on the proper designation,\npackaging, and transport of our Battery Energy Storage System.\n\n<<>>\n\nThe Battery Energy Storage System, also known as the Eos CUBE®, is a containerized energy\nstorage system consisting of 672 individual batteries. Each individual battery contains ~2.2\ngallons of our proprietary electrolyte resulting in aprox. 1,478 gallons of electrolyte per CUBE.\nThe electrolyte is a Zinc Bromide formula where the Zinc Bromide content is in excess of 10%\nweight of the electrolyte. The electrolyte is over 40% distilled water (approx..) with the\nremaining contents consisting of our proprietary mixture.\nAs we mentioned in our conference call, we had our electrolyte tested and we confirmed that\nour electrolyte is NOT corrosive based on the following administered testing:\nUN DOT Coupon Corrosion Testing per ASTM G31, in accordance with UN C.1\nSkin Corrosivity (in vitro) a.k.a. Corrositex® as per the Recommendations on the\nTransportation of Dangerous Goods, Manual of Tests and Criteria, 7th edition revised;\nand/or UN Globally Harmonized System of Classification and Labelling of Chemicals (GHS\nRev. 9, 2021).\nWe also confirmed that our electrolyte is NON-FLAMMABLE based on the following\nadministered test:\nFlash Point Temperature ̶ Pensky-Martens Closed Cup (ASTM D93)\nUsing the ATE (Alternative Toxicity Estimator) methodology, we determined that our\nelectrolyte does not fall within the categories specified to be considered / labeled as a toxic\nand using the same methodology determined that it did nor fall into the criteria for being\neither an acute or chronic marine hazard.\nBased on these determinations we followed UN and DOT transport rules and along with a\nthird-party consultant we came to the conclusion that the proper UN transport number for\nour product for international shipping should be UN 3548, Articles containing miscellaneous\ndangerous goods, n.o.s., (Zinc Bromide), 9 and that our product did not fall under DOT\nregulations when shipping domestic. It is confusing to try to understand how our battery is\nexempt from DOT shipping requirements/regulations (article exemption) but UN3548\nincreases the requirements when shipping international.\nIs there a better designation than UN 3548, or is there a way do get a unique designation for\nour type of battery like was done with Lithium-Ion batteries that has multiple designations\ndependent on the type of battery you are trying to ship? Because when we offered this to our\nbroker, we were told we would need a special permit. Did we make a mistake in our UN\ntransport number? Or, is the permit needed due to special provision A2 under IATA (which is\nincorporated by reg. at 49 CFR part 175) due to the “packaging requirements” for placement\nof dangerous goods on aircraft… or is it due the total amount of electrolyte being\n\n<<>>\n\ntransported?\nAny guidance and/or ruling you could provide would be greatly appreciated!\nThank you in advance for your time and attention.\nDenielle Gower\nDirector of Logistics\nMobile 724-344-4786\neose.com + LinkedIn + Twitter","truncated":false,"body_characters":7494}