PHMSA Response Letter

---

JUN 17, 1998

Ms. Candy L Cook
DGI Training Center
P.O. Box 1283
Amelia Island, FL 32035

Dear Ms. Cook:

This is in response to your letter requesting clarification of quantity limits for carriage on cargo ­only aircraft of hazardous materials which are acceptable for carriage on passenger-carrying aircraft. I apologize for the delay in responding.

Your questions are paraphrased and answered as follows:

Question 1. Packages of hazardous materials acceptable on passenger-carrying aircraft which are stowed aboard a cargo-only aircraft in an inaccessible cargo compartment or in an inaccessible manner within an accessible cargo compartment are limited to 25 kilograms (kg) net weight of hazardous material (and in addition thereto 75 kg net weight of Division 2.2). What is the limitation if the hazardous materials are placed in one or more freight containers aboard the cargo-only aircraft?

If the cargo compartment is accessible, 49 CFR 175.75(a)(2)(ii) permits 25 kg of hazardous materials (reference to the Division 2.2 limit will be ignored for the sake of simplicity) in each freight container, regardless of the number of containers in the compartment. If the cargo compartment is inaccessible, the 25 kg limit applies to the cargo compartment.

Question 2. Is a Class 3, Packing Group ill, material- which is within quantity limits and is acceptable for carriage aboard passenger-carrying aircraft - subject to the 25 kg limit when transported aboard cargo-only aircraft in an inaccessible cargo compartment or in an inaccessible manner within an accessible cargo compartment? Is the same shipment subject to the 25 kg limit if it is offered as acceptable only on cargo aircraft and labeled CARGO AIRCRAFT ONLY?

Section 175.85(c)(1) provides a quantity limit exception from both 49 CFR 175.75(a)(2) and 175.85(b) for Class 3, Packing Group ill materials. Therefore, the shipment is not subject to the 25 kg limit regardless of whether it is offered as acceptable for passenger-carrying aircraft or cargo aircraft only.

Your inquiry highlights two points with regard to the provisions of 49 CFR 175.85. First, although the intent of 49 CFR 175.85(c)(1) is to provide exceptions from both the 49 CFR 175.75(a)(2) quantity limits and the 175.85(b) requirement for accessible stowage, the introductory regulatory text of 49 CFR 175.85(c)(1) fails to specifically reference 49 CFR 175.75. We intend to correct this discrepancy in a future rulemaking. Second, for a material not eligible for the 49 CFR 175.85(c)(1) exceptions, such as a Class 8 material, a shipment which is acceptable for carriage aboard passenger-carrying aircraft is subject to the 25 kg limit when transported aboard cargo-only aircraft in an inaccessible cargo compartment or in an inaccessible manner within an accessible cargo compartment. If the same shipment is offered as acceptable only on cargo aircraft and labeled CARGO AIRCRAFT ONLY, it may only be carried accessibly as required by 49 CFR 175.85(b).

I trust this satisfies your inquiry. If this office can be of further assistance, please contact us.

Sincerely,

Edward T. Mazzullo
Director, Office of Hazardous
Materials Standards

175.75