Non-Fixed Radioactive Contamination Swipe Test
Pipeline and Hazardous Materials Safety Administration · Sep 5, 2006 · Reference No. 06-0153
Interprets: 49 CFR § 173.443
Reggie’s quick take
A U.S. Air Force request asked whether it could get a wipe test waiver for certain chemical agent monitors that carry radioactive material. The agency's answer is that the rule on radioactive contamination in § 173.443 lets a shipper either wipe a 300 square centimeter area and compare the result to the Table 9 limits, or use another method that is at least as efficient. The agency says methods that don't rely on wipe samples, such as new packaging protected from on-site contamination, are acceptable if they ensure compliance. The letter does not grant a waiver.
Written by AI (Claude) on Oct 22, 2026. Robots make mistakes and leave things out, so the letter below is what counts. Not legal advice.
This is in response to your letter dated June 12, 2006, requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) pertaining to the contamination control requirements for Class 7 (radioactive) materials under § 173.443. Specifically, you ask for a wipe test waiver to be granted to the U.S. Air Force for Chemical Agent Monitors (CAMs), Improved Chemical Agent Monitors (ICAMs), and Automatic Chemical Agent Detector Alarms (ACADAs). You have also referenced and enclosed a letter of interpretation from Hattie Mitchell to Vernon Vonders (Ref. No.: 99-0119) that. clarified § 173.443 in regards to the degree of flexibility of contamination control.
Section 173.443 states that "The level of non-fixed radioactive contamination may not exceed the limits set forth in Table 9 and must be determined by either:
(1) Wiping an area of 300 square centimeters of the surface concerned ...; or
(2) Alternatively, the level of non-fixed radioactive contamination may be determined by using other methods of equal or greater efficiency."
Sections 173.443(a)(1) and 173.443(a)(2) continue to allow a shipper the same 1 of flexibility. The shipper must either make one or more wipe measurements and compare the results against the limits in Table 9, or use another method of equal or greater efficiency. As used in § 173.443(a)(2), "efficiency" represents the ratio of a measured value of contamination (such as from a wipe) divided by the actual contamination on the surface of the package, or, in a more general sense, an alternate method which gives the same or greater assurance that the package contamination levels do not exceed the stated regulatory limits. If a shipper utilizes methods which do not rely on actual wipe samples, such as new packaging material which is protected from on-site contamination, ii; is acceptable as long as it ensures compliance.
I hope this information is helpful. Should you have further questions, please contact us.
A letter of interpretation applies the regulations to the facts the requester described. It isn’t a regulation and isn’t legal advice. The agency’s copy.