CheckPoint Mailers Incorporated — Hazardous Materials Safety Interpretation

Page 1U.S. Department 400 Seventh Street, S.W. of Transportation Pipeline and JUL 27 2005 Washington, D.C. 20590 Hazardous Materials Safery Administration Mr. Cliff Bartley Ref. No. 05-0160 Horizon Lines 5800-1 William Mills St., Blount Island Jacksonville, FL 32226 Dear Mr. Bartley: This is in response to your letter requesting clarification of the vessel stowage and segregation requirements for "Nitric acid," UN2031 under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). You state that there are inconsistencies between the HMR and the International Maritime Dangerous Goods (IMDG) Code stowage and segregation requirements for the UN2031 entries. Specifically, you ask whether the HMR stowage and segregation requirements assigned to "Nitric acid, other than red fuming, with more than 70 percent nitric acid," UN2031, Packing Group I, and "Nitric acid, other than red fuming with not more than 70 percent nitric acid," UN2031, Packing Group II are intended to be the same and which requirements apply for a concentration that is less than 50 percent. You also ask the reasoning for assigning Code 111 in § 176.84 to the Packing Group II entry. Currently under the HMR, the stowage and segregation requirements for the Packing Group I and II entries for UN2031 are the same; however, our intent is to align these requirements with the IMDG Code in a future rulemaking. With respect to the assignment of Code 111 to the Packing Group II entry, because the code addresses nitric acid with a concentration that exceeds 50 percent, it does not apply to your material that Tea iconent for your materia for peasa to Tetearn of le than 0 per and segregation 89, 90 and 110 and the stowage category requirement is Category D. Although the IMDG Code stowage and segregation requirements for the UN2031 entries are less restrictive than the current HMR requirements, you may want to consider the 172.101 Subpart B 176.84 050160#

Page 2alternative use of the IMDG Code as authorized with certain conditions and limitations in § 171.12(b). I hope this information is helpful. Please contact this office if you have additional questions. Sincerely, thatle I. Mithell Hattie L. Mitchell, Chief Regulatory Review and Reinvention Office of Hazardous Materials Standards#

Page 3- HORIZON June 23, 2005 MIntyre Mr. Ed Mazzullo Director Office of Hazardous Materials 3112.101 Subpart B Hazardous Materials Standards . $176-84 USDOT / PRMSA / DHM10 400 7# Street S.W. Applicability Segregation Washington, DC 20590 05-0160 Re: Subpart B - Table of Hazardous Materials and Special Provisions - CFR172.101 Dear Mr. Mazzullo, Our company, Horizon Lines, LIC is a domestic containerized ocean transportation company. lazmat regulations. There is some confusion regarding the entry in the hazmat table fi /e are tendered hazardous cargo under both the IMDG regulations as well as the Domesti and the product under PGIl is to be segregated only as a corrosive 8 but the confusion is in the other vessel stowage where the codes for both packing groups of UN2031 are listed as: 44 - Stow "away from" oxidizers 66 - Stow "separated from" flammable solids 89 - Segregation sarne as for oxidizers 90 - Stow "separated from" radioactive materials 110 - Packaging Group Il if concentration does not exceed 70% percent acid 111 - If concentration exceeds 50 percent acid, notes 66, 74*, 89, and 90 apply * (74 - Stow "separated from" oxidizers) On the surface, there seems to be no difference in the stowage. My question is if both entries have the additional stowage requirements as listed above for vessel stowage, is there a difference in the stowage and segregation of the two entries? In reviewing Amendment 32 of the IMDG for this entry, column 16 for stowage and segregation reads: PGI Category D. Segregation as for class 5.1 but "separated from" classes 4.1, 5.1 and 7 PGII Category D. If concentration exceeds 50% acid, segregation as for class 5.1 but "separated from" class 4.1, 5.1 and 7. What is the stowage requirement for nitric acid, UN2031 if the concentration is less than 50% acid and why is the other vessel code 111 listed for the entries in PG1 and PGII? Does that code override the other vessel stow codes? Horizon Lines • Blount Island • 5800-1 William Mills Street • Jacksonville. FL 32226 • 904.757.8266 • www.horizon-lines.com#

Page 4Your help be beneficial in our understanding on the handling of this entry in the regulations. Thank you for your attention to these questions. Sincerely, lill Balle Manager Hazardous Materials Cc: Commandant G-MSO-3 US Coast Guard 2100 2nd Street S.W. Room 1210 Fax 202-267-4570 Washington, DC 20593-0001 Horizon Lines • Blount Island • 5800-1 William Mills Street • Jacksonville, FL 32226 • 904.757.8266 • www.ho-izon-lines.com#