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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Interpretation Response #20-0054

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

Interpretation Response Details

Response Publish Date:

Company Name: Defense Logistics Agency

Individual Name: Joshua Hess

Location State: PA Country: US

View the Interpretation Document

Response text:

September 25, 2020

Joshua Hess
General Supply Specialist
Defense Logistics Agency
2001 Mission Drive
2nd Floor, Suite 6
New Cumberland, PA  17070

Reference No. 20-0054

Dear Mr. Hess:

This letter is in response to your July 27, 2020, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to UN Specification combination packaging test requirements. Specifically, you provide the following scenario:

  • You prepare hazardous materials shipment for air transportation;
  • The hazardous material is placed in a fiberboard (4GV) specification combination packaging;
  • The inner packaging, as provided from the manufacturer, is a paint can that is sealed with a locking ring; and
  • The manufacturer states that "when installed correctly, it allows the paint can to meet 95 kPa" and the requirements of § 173.13.

We have paraphrased and answered your questions as follows:

Q1. You ask whether the entire combination packaging needs to meet the pressure requirements of § 173.27, when the inner packaging meets those pressure requirements.

A1. he answer is no. Section 173.27(c)(2) requires that for transportation by aircraft, packagings for which retention of liquid is a basic function must be capable of withstanding—without leakage—the pressure requirements of either §§ 173.27(c)(2)(i) or (ii), whichever is greater. Therefore, if the inner packaging meets the pressure requirements of § 173.27(c)(2), the outer packaging is not required to also meet those pressure requirements.

Q2. You ask whether the paint can inner packaging could become an intermediary packaging without the entire package being retested. You state that the paint can inner packaging would be filled with another inner packaging that contains the liquid hazardous material.

A2. The answer is yes, if the provisions of § 178.601(g)(2) can be met. The packaging you described in your scenario is marked as having passed the selective testing and meeting the conditions of combination packaging, variation 2 in § 178.601(g)(2) (the "V" in "4GV" marking indicates compliance with this variation). Under certain conditions in § 178.601(g)(2), this variation authorizes the assembly and transportation of a different inner packaging than originally tested. Therefore, if your new inner packaging within the intermediate package configuration can meet the variation 2 requirements, the combination packaging does not need to be retested. If your new configuration cannot meet the variation 2 requirements, the package would need to be retested.

If the provisions of § 178.601(g)(2) cannot be met, the package would need to be retested. By placing an additional inner packaging into the originally tested inner packaging (i.e., paint can), the originally tested inner packaging now meets the § 171.8 definition of an intermediate packaging. Therefore, this new combination packaging would meet the definition of a different packaging and would be required to be retested.

I hope this information is helpful. Please contact us if we can be of further assistance.


Dirk Der Kinderen
Chief, Standards Development Branch
Standards and Rulemaking Division

171.8, 173.13, 173.27, 173.27(c)(2), 173.27(c)(2)(i) or (ii), 178.601(g)(2)

Regulation Sections

Section Subject
171.8 Definitions and abbreviations
173.13 Exceptions for Class 3, Divisions 4.1, 4.2, 4.3, 5.1, 6.1, and Classes 8 and 9 materials
173.27 General requirements for transportation by aircraft
178.601 General requirements