Pillsbury Winthrop — Hazardous Materials Safety Interpretation

Page 1of Transportation U.S. Department 400 Seventh St., S.W. Washington, D.G. 20590 Research and Special Programs Administratior JUL 1O 2003 Mr. David M. Hernandez Senior Associate Pillsbury Winthrop Reference No. 03-0158 1133 Connecticut Avenue, NW Washington, DC 20036 Dear Mr. Hernandez: This responds to your June 24, 2003 letter requesting a clarification, on behalf of Texaco Ovonic Hydrogen Systems, L.L.C., on the applicability of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) to a motor vehicle powered by hydrogen contained in a metal hydride storage system. Specifically, you inquired whether your client's motor vehicle when transported by highway is excepted from all requirements of the HMR as provided in § 173.220(e)(1). within the exceptions provided in § 173.220(b)(2) and (d)(1). Therefore, when the fuel system is The answer is yes. The fuel system, the metal hydride storage system containing hydrogen, falls securely installed and closed during transportation, the motor vehicle is not subject to any other requirements of the HMR as provided in paragraph (e)(1). I hope this satisfies your inquiry. If you have further questions, please do not hesitate to contact this office. Sincerely, Director, Office of Hazardous Edward T. Mazzullo Materials Standards 173.220 030158#

Page 2PILLSBURY WINTHROP uP 1133 CONNECTICUT AVENUE NW WASHINGTON, DC 20036 202.775.9800 F: 202.833.8491 June 24, 2003 David M. Herandez Senior Associate 202.775.9824 Via Certified Mail - Return Receipt Requested dhernandez@pillsburywinthrop.com Edward T. Mazzullo Office of Hazardous Materials Standards, DHM-10 Director Room 8422 400 7th Street, SW Washington, DC 20590-0001 Re: Shipment of Self-Propelled Hydrogen/Metal Powered Vehicle Under 49 C.F.R. 173.220. Dear Mr. Mazzullo: Texaco Ovonic Hydrogen Systems, L.L: C. ("Texaco Ovonic") will be offering for hydrogen contained in a metal hydride storage system. transport, aboard an automobile transport truck or trailer, a motor vehicle powered by Based upon our review of Section 173.220 of the Hazardous Materials Transportation Regulations, we believe that the metal hydride storage system falls within the exception provided in subsection (d)(1) for "other hazardous materials." It is our requirements of the regulations as provided in subsection (e)(1) of that regulation, and by view, theretore, that the shipment of the motor vehicle is not subject to any other this letter are requesting your concurrence in the correctness of this determination. We are aware that staff in your office is familiar with the metal hydride storage system, and have determined that, notwithstanding the presence of other substances in the vessel, these storage systems should be classified on the basis of the hazards of the article, hydrogen. See Comments of the U.S. expert on Agenda Item 4(b)(ii)(2002) (enclosed). In this regard, the vehicles would present a hazard in transportation no different than one provided by compressed hydrogen which is authorized to be transported by Section 173.220, including the exception provided in subsection (e)(1). To meet a scheduled vehicle demonstration program, we hope to move the vehicle by the end of this month. Therefore, your concurrence with our determination at the earliest possible time would be greatly appreciated. 160256841v2#

Page 3PILLSBURY WINTHROPur June 24, 2003 Page 2 (202) 775-9824. If you have any questions or request additional information, please contact me at Very truly yours, Enclosure (1) CC: Dr. Charles H. Ke Office of Hazardous Materials Technology Room 8430 Reaction Materials, DHM-21.1 400 7" Street, S.W. Washington, DC 20590-0001 160256841V2#

Page 4UN/SCETDG/22/INF.22 COMMITTEE OF EXPERTS ON THE TRANSPORT OF DANGEROUS GOODS AND ON THE GLOBALLY HARMONIZED SYSTEM OF CLASSIFICATION AND LABELLING OF CHEMICALS Sub-Committee of Experts on the NEW PROPOSALS Hydrogen in a Metal Hvaride Svstem Comments on ST/SG/AC.10/C.3/2002/83 Transmitted bv the expert from the United States of America 1. ST/SG/AC. 10/C.3/2002/83 to adopt a new entry for "Hydrogen In A Metal Hydride Storage The expert from the United States of America supports the expert from Canada's proposal in System". Adoption of an entry in the Model Regulations for Hydrogen/Meral Hydride Storage these articles in commerce. While we ivelcome the Canadian proposal, it is the opinion of the United Systems will facilitate the transport of these systems especially considering the rapid introduction of unnecessary assignment of sub-risks for hydrogen/metal hydride storage systems. We expressed our States thar adoption of the proposed Special Provision CCC will lead to inconsistent and reservation on this point at the twenty-first session of the Sub-committee meeting in July, 2002, and entry and adequately addresses the hazards of such a system. We do nor agree that it is necessary or after further review. maintain our position that a Division 2.I classification is sufficient for this new appropriate to require a Class 4 subsidiary risk for this new entry. Our view is supported by the 2. The text of the proposed Special Provision CCC will create difficulties and confusion for consignors and will lead to inconsistent assignment of subsidiary risks for these hydrogen/metal hydride storage systems. If SP CCC is adopted consignors will be required to determine the state and composition of the hydridable metal alloys for hydrogen storage in order to apply the appropriate subsidiary risk. pressure in the storage system as well as the amount of hydrogen absorbed within the alloy. The This will be difficult because the state and composition of the hydridable metal depends on the metal alloys wilt change based on whether it is in the in the activated, non-hydrided state or the amount of hydrogen absorbed will change during the use of the system and the hazard posed by the these metal alloys in the state in which they will be offered for transport. Adoption of SP CCC will hydrided state. Furthermore. the UN tests and criteria for Class 4 substances can not be applied to also require consignors of used systems to reassess the hazards to determine if the sub-risk has purged or cleaned storage system to ship that system (basically is metals in a container) under SAAA changed before offering the systems for transport. Since CCC requires persons who transport a with a primary hazard assignment of Division 2.1 and a subsidiary risk assignment of Div. 4.1 or 4.2 or 4.3 consignors will need to asses every system prior to transport to determine the appropriate hazard classificacion.#

Page 5UN/SCETDG/22/INF.22. page 2 3. In actuality, if the materials are removed from the containment and suddenly exposed, they will this real-life situation, the rapid release of hydrogen would cool the marerial and slow the oxidation release hydrogen as designed, revert to the non-hydrided state and undergo oxidation. However in process. In this case, the oxidation would most likely be slow enough to prevent the possible ignition of nearby combustible materials. The material within the storage system will not behave the same as other Division 4.2 substances when exposed due to the dehydriding reaction that will occur. In tests canisters rapidly vented hydrogen and cooled sufficiently to form ice on the vessel surface. The conducted in the Uniced States, in which storage systems with hydrided material were ruptured. the cooling and ice formation slowed the hydrogen release and no effects from the oxidation of the alloy for requiring the subsidiary risks that would be required according to the proposed SP CCC. Since were observed. On this basis, the hazards posed by the metal alloys do not seem to justify the need overpressure of hydrogen, the classification process will most likely be applied inconsistently and the test and criteria for Class 4 merals can't be applied to a metal alloy that is subject to an will lead to confusion for consignors as well as compliance inspectors. The expert from the United article as opposed to classificacion on the basis of each of the substances contained. For these Scates believes that the classification of these storage systems should be based on the hazards of the reasons stated above, we do not support the adoption of SP CCC as proposed in -C.3/2002/83. Proposal 4. ST/SG/AC. 10/C.3/2002/83 with the exception of SP CCC. The Sub-Committee is requested to adopt the expert from Canada's proposal as indicated in#