Interpretation Response #05-0124 ([U.S. Coast Guard MSO Jacksonville] [Lt. John Fitzgerald])

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date: 06/29/2005

Company Name: U.S. Coast Guard MSO Jacksonville

Individual Name: Lt. John Fitzgerald

Location State: FL Country: US

View the Interpretation Document

Response text:

Jun 29, 2005

Lt. John Fitzgerald                      Reference 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 Materials Regulations (HMR; 49 CFR Parts 171-180). Specifically, you ask us to clarify the vessel segregation requirements specified in § 176.83.

You ask us to reconsider an interpretation that was issued on June 1, 1995 to Ken 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 IE and they were not incompatible.

Section § 176.83(a)(8) was amended on June 2, 1999 under Docket No. RSPA-98-4185 (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 required by secondary hazards (subsidiary risk label(s)), provided the substances do not react dangerously with each other and cause: (i) combustion and/or evolution of 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.

Because 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,

John A. Gale
Chief, Standards Development
Office of Hazardous Materials Standards

176.83 (a)(8)

Regulation Sections