HMT Associates, L.L.C. — Hazardous Materials Safety Interpretation

Page 1U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration 1200 New Jersey Avenue, SE Washington, D.C. 20590 MAR 1 9 2014 Ms. Patricia Quinn HMT Associates, L.L.C. 603 King Street, Suite 300 Alexandria, VA 22314-3105 Ref. No. 14-0004 Dear Ms. Quinn: This is in response to your January 8, 2014 email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CPR Parts 171-180) concerning the filling capacity of cylinders manufactured and used under DOT -SP 1 0788. This special permit authorizes a non- specification cylinder, conforming to a specification DOT 39 cylinder, except that the requirement of§ 173.302a(a)(1) is waived. Specifically, you ask if a cylinder authorized under DOT SP-10788 is subject to§ 173.302a(a)(3) which limits the capacity of a DOT 39 cylinder not to exceed 1.23 L (7 5 cubic inches) when filled with a Division 2.1 material. In your letter you note that paragraph 7 of the special permit states that the cylinder's maximum water capacity may not exceed 10 pounds (277 cubic inches). The answer is yes. Cylinders manufactured or used under DOT-SP 10788 are subject to the 1.23 L (75 cubic inches) limit prescribed in§ 173.302a(a)(3) when filled with a Division 2.1 material. DOT-SP 10788 provides that cylinders authorized under this special permit must conform to the requirements of a specification DOT 39 cylinder except that the requirement of§ 173 .302a( a)( 1) is waived. The maximum water capacity of 1 0 pounds (277 cubic inches) referenced in paragraph 7 of the special permit is a standard requirement for DOT 39 cylinders with a service pressure exceeding 500 p.s.i.g. and not unique to DOT -SP 10788. I hope this information is helpful. If you have further questions, please contact this Office. Sincerely, International Standards Coordinator Office of Hazardous Materials Standards#

Page 2HMT ASSOCIATES, L.L.c. 603KINGST. SUITE300 ALEXANDRIA, VA223i4·3105 703·549-0727 FACSIMILE: 703·549·0728 E. A. ALTEMOS PATRICIA A. QUINN WRITER'S DIRECT DIAL NUMBER (703) 549-0727 January 8, 2014 Mr. Charles Betts Director, Office of Hazardous Materials Standards U.S. Department of Transportation PHH-10, East Building, 1200 New Jersey Avenue, SE Washington, DC 20590 Dear Mr. Betts: RE: Request for Interpretation of 49 CFR 173.302a (a)(3) This letter is to request an interpretation of the applicability ofthe requirement in 49 CFR 173.302a (a)(3), which limits the capacity of a DOT specification 39 cylinder to not to exceed 1.23 L (75 cubic inches) when filled with a Division 2.1 material, to non- specification cylinders being manufactured and used under DOT special permit, DOT -SP 10788. DOT -SP 10788 (copy attached) authorizes a non-specification cylinder, conforming to a DOT specification 39 cylinder, except as provided in the permit. The regulation waived in the permit is 49 CFR 173.302a (a)(l). Under paragraph 7., of DOT-SP 10788, the maximum water capacity of the non-specification cylinder may not exceed 10 lbs. (277 cubic inches). In addition, paragraph 6., authorizes Division 2.1 flammable gases listed in 49 CFR that are authorized in DOT specification 39 cylinde1s. Does the requirement in 49 CFR 173.302a (a)(3), that limits the capacity of a DOT specification 39 cylinder not to exceed 75 cubic inches when filled with a Division 2.1 material, apply to the cylinders being used under DOT -SP 10788 that may be manufactured up to 277 cubic inches? Are you limited under the special permit when filling the non-specification cylinders with Division 2.1 materials to 75 cubic inches? Since the cylinders authorized by DOT-SP 10788 are not DOT specification 39 cylinders, but rather non-specification cylinders, the applicability of 49 CFR 173.302a (a)(3) is not clear.#

Page 3HMT ASSOCIATES, L.L.C. Mr. Charles Betts January 8, 2014 Page2 Please do not hesitate to contact me at 703-549-0727, or by e-mail to pquinn@pipeline.com if you have any questions concerning this request. Attachment: DOT -SP 10788#