U.S. Coast Guard MSO Jacksonville — Hazardous Materials Safety Interpretation

Page 1of Transportation U.S. Department 400 Seventh Street, S.W. Washington, D.C. 20590 Pipeline and Administration Hazardous Materials Safety JUN 29 2005 Lt. John Fitzgerald Ref No.: 05-0124 U.S. Coast Guard MSO Jacksonville 7820 Arlington Expressway, Suite 400 Jacksonville, FL 32211 Dear Lt. Fitzgerald: This responds to your May 20, 2005 letter requesting clarification of the Hazardous the vessel segregation requirements specified in § 176.83. Materials Regulations (HMR; 49 CPR Parts 171-180). Specifically, you ask us to clarify You ask us to reconsider an interpretation that was issued on June 1, 1995 to Ker. Prater of Cotter & Company as it would apply to acetylene (Division 2.1) and oxygen (Division 2.2 primary and Division 5.1 subsidiary hazard). In that letter we interpreted the regulations in effect as of June 1, 1995. Section 176.83 required Division 2.1 materials to be segregated "separate from" materials with oxidizing properties (i.e., oxygen). However, § 176.83(a)(8) permitted hazardous materials of the same class to be stowed together without regard to segregation required by the secondary hazard if the materials were not incompatible. The letter authorized propane (Division 2.1) to be stowed. together with oxygen (Division 2.2 primary and Division 5.1 subsidiary hazard) when transported by vessel because we considered the two materials to be of the same class (Class 2), under the HIMR and they were not incompatible. Section § 176.83(a)(8) was amended on June 2, 1999 under Docket No. RSPA-93-4185 (HM-215C). The revised language in § 176.83 currently states that "..hazardous materials of the same class may be stowed together without regard to segregation eact dangerously with each other and cause: (i) combustion and/or evolution o equired by secondary hazards (subsidiary risk label(s)), provided the substances do no considerable heat; (ii) evolution of flammable, toxic or asphyxiant gases; (iii) the formation of corrosive substances; or, (iv) the formation of unstable substances." For the purposes of the general segregation table in § 176.83(b), we now consider Division 2.1 and Division 2.2 materials to be of different classes, and they are listed as such in the table. This is consistent with the approach in the International Maritime Dangerous Goods (IMDG) Code. 176.83 (a)8) 050124#

Page 2Because Acetylene (Division 2.1) and Oxygen (Division 2.2) are now considered separate classes for the purposes of § 176.83(b), the subsidiary hazard must be used to determine the appropriate segregation. Therefore, acetylene must be stowed "separated from" oxygen. This will be clarified in a future rulemaking. I hope this information is helpful. Please contact us if you require additional assistance. Sincerely, Xina Im, John A. Gale Chief, Standards Development Office of Hazardous Materials Standards#

Page 3INFOCNTR <PHMSA> From: Eichenlaut Sent: jfitzgerald@msojax.uscg.mil Subject: To: INFOCNTR <PHMSA> Friday, May 20, 2005 10:31 AM 5176.83 G) (8) Information Center Comments/Questions Segregation Below is the result of your feedback form. It was submitted by 05-0124 LT John Fitzgerald (jfitzgerald@msojax.uscg.mil) on Friday, May 20, 2005 at 10:31:06. Email: jfitzgerald@msojax.uscg.mil Name : LT John Fitzgerald Category: Interpretations (Letters) issued by PHMSA Organization: US Coast Guard MSO Jacksonville Street: 7820 Arlington Expressway, Suite 400 City: Jacksonville State: Florida Zip Code: 32211 Phone: 904-232-2640 sext 140 - Comancer Ronalds Fax: 904-232-1014 Comments: IMMEDIATE RESPONSE NEEDED. May 20, 2005 I need a re-interpretation of Cotter and Company, 1995. The original interpretation apply this interpretation to the segregation of acetylene and oxygen. segregation of propane and oxygen. Currently, we (USCG) have been requested to 49CFR176.83 (a) (8).. Cotter and Company interpretation applies. ., I do not believe that the requested application of the orginal 1995 have military and commercial shipments that wish to apply this standard today. Please provide me with clarification as we#