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Interpretation Response #05-0052 ([Duratek Training Services] [Ms. Kathryn Pacha])

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

Interpretation Response Details

Response Publish Date:

Company Name: Duratek Training Services

Individual Name: Ms. Kathryn Pacha

Location State: SC Country: US

View the Interpretation Document

Response text:

Apr 13, 2005


Ms. Kathryn Pacha                       Reference No. 05-0052
Training Services Manager
Duratek Training Services
140 Stoneridge Drive, Suite 500
Columbia, South Carolina 29210

Dear Ms. Pacha:

This is in response to your letter dated March 2, 2005 regarding the overpacking of packages of Class 7 (radioactive) material under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180).

In your letter you describe a scenario where multiple drums have been placed onto a pallet. Specifically, :you state that two packages of limited quantity Class 7 (radioactive) material and two packages of Class 7 (radioactive) material that are appropriately labeled RADIOACTIVE YELLOW-II have been place onto a pallet. Based on your scenario you ask the following questions, which are paraphrased and answered below:

Q1)      For the above described scenario, would multiple drums placed on a pallet for shipment be considered an overpack?

Al)       The answer is yes. An overpack, as defined in § 171.8, means an enclosure used by a single consignor to provide protection or convenience in handling of a package or to consolidate two or more packages. Each inner packaging must be marked and labeled in accordance with the HMR. In addition, when an overpack is used, it must be marked with the proper shipping name and identification number, and labeled for each hazardous material it contains unless the markings and labels representative of each hazardous material in the overpack are visible. When the markings and labels representative of each hazardous material in the overpack are not visible, and the overpack contains one or more packages of Class 7 (radioactive) material, then in addition to the labels for any other hazard classes present, a single radioactive label is required to be placed on the overpack in accordance with the requirements of § 172.403(h). The overpack must also be marked with the word “OVERPACK” when specification packagings are required, unless specification markings on the inside packages are visible. Alternatively, until October 1, 2007, the overpack may be marked with a statement indicating that the “inside (inner) packages comply with prescribed specifications.”

Q2)    If the answer to question Q1 is yes, would the dose rate apply to the individual drums?

A2)  The answer is yes, with the caveat that if a radioactive label is needed for the overpack, the category of the overpack radioactive label may depend on individual package dose rates as well. Paragraphs 172.203(d)(4) and (d)(5) require both the category of radioactive label and the transport index (TI) to be listed in the shipping description for each individual package on the shipping paper. Package dose rates are used to determine the (TI) and category of radioactive label for individual packages. (The TI is the dimensionless number equivalent in numerical value to the maximum dose rate in mrem/hour at one meter from the package.) The category of label for an individual package is determined from a combination of its maximum surface dose rate and its TI. Note that for the example in the above scenario, you must identify the presence of the two RADIOACTIVE YELLOW —II labeled packages on the shipping paper, but are not required to do so for the two limited quantity packages, unless these contain a hazardous substance or a hazardous waste.

In addition, when the markings and labels representative of each hazardous material in the overpack are not visible, and the overpack contains one or more packages of Class 7 (radioactive) material, a single radioactive label must be placed on the outside of the overpack. In accordance with § 172.403(h), the category of label for the overpack is determined on the basis of the maximum surface dose rate of the overpack and either the sum of the individual package TIs or, in the case of a rigid overpack, one has the option of measuring the TI of the overpack. Therefore, if the choice is made to measure the TI of the overpack, one need not know any individual package dose rates in order to determine the category of radioactive label for the overpack.

Q3)      When a rigid overpack is used, would the issue of what label to apply become applicable?

A3)      The answer is yes. Section 172.403 requires that the category of the Class 7 label for the overpack must be determined from the table in § 172.403(c) using the TI derived according to the maximum radiation at the surface and the following:

  • The TI must be determined by adding together the transport indices of the Class 7 (radioactive) materials packages contained therein (see Q2 above), except
  • For a rigid overpack, the TI may alternatively be determined by direct measurement as prescribed in § 173.403 under the definition for “transport index,” taken by the person initially offering the packages contained within the overpack for shipment.

Q4)      If a non-rigid overpack is used, would the option of applying a label and determining a new dose rate be non-applicable, as long as the markings and labels are visible?

A4)      The answer is yes.

I hope this information is helpful.



Susan Gorsky
Acting Director Hazardous Materials Standards
Office of Hazardous Materials Standards


Regulation Sections

Section Subject
173.25 Authorized packagings and overpacks