## Facts

- Aerotech, a manufacturer of ammonium perchlorate composite propellant (APCP) used in hobby rocket motors, wrote to the United States Bureau of Alcohol, Tobacco and Firearms (ATF) asking how federal explosives regulation would affect its operations.
- ATF responded by letter stating that APCP was an “explosive” under federal explosives law and that rocket motors containing more than 62.5 grams of APCP would be regulated (while smaller motors could be treated as exempt).
- Tripoli Rocketry Association, Inc. and the National Association of Rocketry are nonprofit hobby rocketry organizations whose members use APCP-powered motors in sport rocketry.
- Plaintiffs contended that ATF’s positions effectively subjected many high-power rocket motors to federal explosives licensing, storage, and related requirements.
- Plaintiffs challenged several ATF actions and positions under the Administrative Procedure Act (APA), including: (i) ATF’s classification of APCP as an explosive under the statutory definition in 18 U.S.C. § 841(d); (ii) ATF’s continued inclusion of APCP on the annually published “List of Explosive Materials” without notice-and-comment procedures; (iii) ATF’s conclusion that sport rocket motors are not exempt “propellant actuated devices” (PADs); and (iv) ATF’s selection of a 62.5-gram propellant cutoff for an exemption for certain motors.
- The case was decided in the United States District Court for the District of Columbia on cross-motions for summary judgment seeking review of ATF’s actions under APA standards.

## Issues

1. Whether ATF acted lawfully in classifying APCP as an “explosive” under 18 U.S.C. § 841(d).
2. Whether ATF’s annual publication and revision of the “List of Explosive Materials,” including APCP, required notice-and-comment rulemaking under the APA.
3. Whether ATF reasonably concluded that sport rocket motors do not qualify for the regulatory exemption for “propellant actuated devices.”
4. Whether ATF’s decision to exempt only motors containing 62.5 grams or less of APCP was arbitrary or capricious under the APA.

## Decision

- The court upheld ATF’s classification of APCP as an “explosive” within the meaning of 18 U.S.C. § 841(d).
- The court held that including APCP on ATF’s annually published “List of Explosive Materials” did not require notice-and-comment rulemaking.
- The court upheld ATF’s determination that sport rocket motors are not exempt “propellant actuated devices” under ATF’s regulations.
- The court upheld ATF’s 62.5-gram exemption line for certain rocket motors as a permissible safety-based judgment supported by the record.
- The court granted summary judgment to ATF and denied plaintiffs’ requested relief under the APA.

## Legal Principles

- Under the APA, a reviewing court may set aside agency action that is arbitrary or capricious, exceeds statutory authority, or is taken without required procedure. 5 U.S.C. § 706(2).
- When an agency applies a statutory definition administered by the agency, courts evaluate the statute’s text and structure and may defer to a reasonable agency interpretation under *Chevron* principles.
- Items that deflagrate (rather than detonate) can fall within the federal explosives definition where the statute’s language and examples show Congress treated certain deflagrating materials as “explosives.”
- A statutorily required annual publication that identifies materials within an existing statutory definition may be treated as implementing the statute rather than creating a new binding legislative rule that triggers APA notice-and-comment requirements.
- Courts generally defer to an agency’s reasonable interpretation of its own regulations concerning the scope of an exemption, so long as the reading is consistent with the regulatory text.
- Agency line-drawing on safety thresholds will be sustained under the APA when the agency offers a reasoned explanation and record support for the cutoff it selected.

## Conclusion

Tripoli and NAR challenged ATF’s treatment of APCP and related sport rocketry policies as unlawful under the APA, arguing that APCP should not be regulated as an explosive, that listing APCP required notice and comment, that sport rocket motors qualified for the PAD exemption, and that the 62.5-gram cutoff was unsupported. The D.D.C. rejected these claims, upheld ATF’s interpretation of the explosives statute and its own regulations, and entered summary judgment for ATF.


Tripoli Rocket Association, Inc. v. United States Bureau of Alcohol, Tobacco and Firearms, 2002 WL 33253171 (2002)