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Interpretation Response #06-0097 ([Ms. Kristen Taddonio ])

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

Interpretation Response Details

Response Publish Date:

Company Name:

Individual Name: Ms. Kristen Taddonio 

Location State: DC Country: US

View the Interpretation Document

Response text:

Jul 11, 2006


Ms. Kristen Taddonio                 Reference No. 06-0097

2450 Virginia Avenue, N. W.

Apartment E-111

Washington, D. C. 20037

Dear Ms. Taddonio:

This responds to your letter dated April 13, 2006, regarding clarification of the requirements in the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) as they apply to the shipment of an air conditioning system accumulator installed in a motor vehicle. In a subsequent phone conversation with a member of my staff, you said the air conditioning system contained a refrigerant gas accumulator built into the mechanics of an automobile. Your questions are paraphrased and answered as follows:

Q1. Under §173.306(f)(1), accumulators installed in motor vehicles and fabricated with a burst pressure of not less than five (5) times their charged pressure at 70°F., when shipped, are not subject to the HMR. What requirements apply to an air conditioning system accumulator installed in a motor vehicle if it is only fabricated to withstand 4.5 times the charged pressure at 70°F?

Al. In accordance with §173.306(f) (5), accumulators not conforming to the provisions of paragraphs (f) (1) through (f) (4) of this section, (e.g., an accumulator installed in a motor vehicle and fabricated to withstand only 4.5 times the charged pressure) may be shipped only under the terms of an approval issued by the Associate Administrator of the Office of Hazardous Materials Safety.

Section 173.220(e) of the HMR specifies that items of equipment containing a hazardous material, such as a compressed gas accumulator, that is an integral component of a motor vehicle and necessary for the operation of the vehicle and securely installed in the motor vehicle, are not subject to the HMR. Based on the information you provided, the air conditioning system containing a refrigerant gas accumulator built into the mechanics of the motor vehicle is not subject to the HMR

Q2. How does one apply for an approval?

A2. You may apply for an approval in accordance with the requirements specified in

§ 107.705.

I hope this information is helpful. If we can be of further assistance, please contact us.



John A. Gale

Chief, Standards Development

Office of Hazardous Materials Standards

173.306 (f)(5), 173.220 (e)

Regulation Sections

Section Subject
173.220 Internal combustion engines, vehicles, machinery containing internal combustion engines, battery-powered equipment or machinery, fuel cell-powered equipment or machinery
173.306 Limited quantities of compressed gases