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Interpretation Response #25-0163

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

Interpretation Response Details

Response Publish Date:

Company Name: Catawba Corps

Individual Name: John B. Woodbury

Location State: ID Country: US

View the Interpretation Document

Response text:

June 25, 2026

John B. Woodbury
Packaging Management Council Coordinator
Catawba Corps
3533 15th Street E
Lewiston, ID  83501

Reference No. 25-0163

Dear Mr. Woodbury:

This letter is in response to your December 15, 2025 email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to fissile materials. Specifically, you ask whether a liquid payload can qualify for the fissile exceptions in § 173.453(b).

Yes. In order to qualify for the fissile material exceptions in § 173.453(b), the packaging must contain "15 grams or less of fissile material provided the package has at least 200 grams of solid nonfissile material for every gram of fissile material." While the nonfissile material in this calculation must be solid, § 173.453(b) does not require that the fissile material be solid.

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

Sincerely,

Alexander Wolcott
Acting Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division

173.453(b)

Regulation Sections