PHMSA Response Letter

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JUN 26, 1998

Mr. H.J. Pace
President, CEO
Hazmat Guru Consulting
6917 Kirkwood Road
Fort Worth, TX 76116-9420

Dear Mr. Pace:

This is in response to your letter requesting clarification of quantity limits for carriage on cargo-only aircraft of hazardous materials in inaccessible cargo compartment. I apologize for the delay in responding.

Your questions have been paraphrased and answered as follows:

Question 1. How much hazardous material acceptable for passenger or cargo aircraft may be transported in an inaccessible cargo compartment or freight container?

Passenger authorized hazardous materials that are carried aboard passenger aircraft in inaccessible compartments are limited by 49 CFR 175.75(a)(2)(D to 25 kg. of hazardous materials (reference to the Division 2.2 limit will be omitted for the sake of simplicity) per compartment, whether in a freight container or not. Passenger authorized hazardous materials carried aboard cargo-only aircraft in inaccessible compartments or an inaccessible manner within an accessible compartment are limited to 25 kg. of hazardous material per compartment when not in freight containers. If a passenger authorized hazardous material is carried within freight containers in an accessible cargo compartment, they are limited to 25 kg. of hazardous material per freight container.

Question 2. How much cargo-only authorized hazardous materials carried aboard cargo-only aircraft are allowed to be transported in an inaccessible cargo compartment?

The answer is none. Section 175.85(b) prohibits the carriage of hazardous materials
acceptable only for cargo aircraft from being carried in an inaccessible fashion. Except as provided in 49 CFR 175.85(c), hazardous materials prepared for transportation by cargo-only aircraft must always be accessible by the flight crew.

Your inquiry highlights some of the difficulty which has been experienced in interpreting §§ 175.75 and 175.85. We are currently examining all of the provisions of 49 CFR Part 175, and intend to correct discrepancies in a future rulemaking.

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