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Interpretation Response #11-0163 ([International Radiation Safety Consulting, Inc.] [Mr. Sean Chapel])

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

Interpretation Response Details

Response Publish Date:

Company Name: International Radiation Safety Consulting, Inc.

Individual Name: Mr. Sean Chapel

Location State: MA Country: US

View the Interpretation Document

Response text:

September 7, 2011




Mr. Sean Chapel


International Radiation Safety Consulting, Inc.

17 Norfolk Road

Holbrook, MA 02343

Ref. No.: 11-0163

Dear Mr. Chapel:

This responds to your July 12, 2011 letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171"180) applicable to the transportation of excepted packages for radioactive instruments and articles. Your questions are paraphrased and answered below.

Q1: You ask whether, under the requirements for excepted packages for radioactive instruments and articles and contamination control (see §§ 173.424(g) and 173.443(a)), a shipper may perform a wipe test on the instrument itself instead of the actual external surface of the package?

A1: Provided certain conditions are met, the answer is yes. As required by § 173.424(g), the non-fixed (removable) radioactive surface contamination on the external surface of the package must meet the requirements specified in § 173.443(a), which has both a quantitative upper limit, and an as-low-as reasonably achievable component. Section 173.443(a) requires that the level of non-fixed radioactive contamination may not exceed the limits set forth in Table 9 of § 173.443.

The shipper must either make one or more package wipe measurements and compare the results against the limits in Table 9, or use another method of equal or greater efficiency. If a shipper utilizes a method which relies on a wipe test on the instrument itself instead of the actual external surface of the package, it is acceptable provided it is of equal or greater efficiency than the methodology in § 173.443(a)(1) and meets compliance.

Q2: You ask whether it would be necessary to wipe test every device to demonstrate compliance, or if a representative sample of devices per lot shipped could be wipe tested? Further, you ask what minimum criteria would constitute a representative sample?

A2: A physical contamination survey on the outside of every package, or a wipe test on every device, is not mandated prior to each shipment. Furthermore, there is no minimum criterion of what would constitute a sample. The contamination limits must be met, and it is the shipper's responsibility to determine the methodology, as permitted by § 173.443(a)(2), to be utilized by its operations while maintaining compliance with the requirements of the HMR. It should be noted that many shippers survey every package because they do not want to assume the increased perceived risk of using an alternate method that might allow a contamination non-compliance issue.

I hope this satisfies your inquiry. Please contact us if we can be of further assistance.



T. Glenn Foster

Chief, Regulatory Review and Reinvention Branch

Standards and Rulemaking Division

173.443, 173.424(g)

Regulation Sections

Section Subject
173.424 Excepted packages for radioactive instruments and articles
173.443 Contamination control