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U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Interpretation Response #12-0038 ([Mr. Charles E. Tudor])

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: Mr. Charles E. Tudor

Location State: WA Country: US

View the Interpretation Document

Response text:

May 7, 2012

 

Mr. Charles E. Tudor, CP-P/MH
12419 Entiat River Road
Entiat, WA 98822

Reference No.: 12-0038

Dear Mr. Tudor:

This responds to your January 23, 2012 letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the packaging of nitrous oxide in non-specification cylinders. In your incoming letter, you describe a scenario in which your client intends to ship 7.5 grams of nitrous oxide in a 10-ml non-specification cylinder via air and vessel internationally. These nitrous oxide non-specification cylinders are to be used in medical devices. Based on this scenario, your questions are paraphrased and answered as follows:

Q1. Is nitrous oxide permitted to be transported in 10-ml non-specification cylinders for domestic and international air transport?

A1. The answer is no. The Column 7 entry in the Hazardous Materials Table (HMT; § 172.101) for "UN 1070, Nitrous Oxide" lists Special Provision A14. Special Provision A14 states that nitrous oxide is not authorized to be transported as a limited quantity in accordance with § 173.306 when transported by aircraft. Therefore, nitrous oxide, when transported by air, must comply with the requirements specified in either §§ 173.304, 173.314, or 173.315. Specifically,
§ 173.304(f) provides the authorized specification cylinders permitted, filling requirements, and outer packaging requirements for the air transport of oxidizers, including nitrous oxide. Nitrous oxide would only be permitted to be shipped by aircraft in a non-specification cylinder if the shipment utilized a special permit. It should be noted that nitrous oxide transported by highway, rail or vessel meeting the limited quantities for compressed gas requirements specified in § 173.306 may be transported in non-specification cylinders.

Q2. If nitrous oxide is permitted to be transported in 10-ml non-specification cylinders for domestic and international air transport, what filling limits should be used?

A2. As noted above, nitrous oxide is not permitted to be shipped in 10-ml non-specification cylinders by air unless a special permit is issued providing relief from the requirements of the HMR. Furthermore, as specified in the table in
§ 173.304a(a)(2), nitrous oxide has a maximum filling density of 68% when transported in accordance with the HMR. Shipments transported under the International Civil Aviation Organization"s Technical Instructions (ICAO TI) must comply with the filling limits listed in packing instruction (PI) 200.

Q3. Does USG 18 and § 173.304(f) apply to air shipments of nitrous oxide?

A3. The answer is yes. For air shipments of nitrous oxide transported in the United States, both USG 18 and § 173.304(f) would apply.

Q4. Does PHMSA require fire-resistant outer packaging on vessel shipments of oxidizers, specifically nitrous oxide?

A4. The answer is no. The requirements in § 173.304(f)(3) requiring a rigid fire-resistant outer packaging are specific to air shipments of oxidizing gases. There is no analogous requirement for vessel transport.

Q5. Should 10-ml nitrous oxide non-specification cylinders be treated as "articles" and be packaged in accordance with PI 003 as indicated by the International Maritime Dangerous Goods (IMDG) code?

A5. In accordance with § 173.22 and Chapter 2 of the IMDG code, it is the shipper"s responsibility to properly class and describe a hazardous material. This Office does not perform that function. However, it is the opinion of this Office that, the scenario you describe, "UN 1070, Nitrous Oxide" is the most appropriate proper shipping description. Furthermore, under the IMDG code "UN 1070, Nitrous Oxide" should be packaged in accordance with PI 200.

Q6. If the 10-ml nitrous oxide non-specification cylinders are to be treated as "articles" are they required to be packaged in combination packagings that have been UN performance tested?

A6. As stated in A5, it is the opinion of this Office that in the scenario you describe "UN 1070, Nitrous Oxide" is the most appropriate proper shipping description. Therefore, for vessel transport under the HMR, the nitrous oxide could be packaged in accordance with §§ 173.304, 173.306, 173.314, or 173.315. Under the IMDG code, nitrous oxide should be packaged in accordance with PI 200.

Q7. Is there an existing special permit covering the nitrous oxide cartridges described above?

A7. PHMSA"s Approvals and Permits Division has issued special permits authorizing the use of non-specification cylinders for the air transport of nitrous oxide under specific transport conditions and after a technical review of the non-specification cylinder. Based on the schematic drawing you provided in your incoming letter, it does not appear as if your non-specification cylinder has been issued a special permit. Under § 107.105, you may apply for your own special permit that authorizes air shipment of nitrous oxide in non-specification cylinders. You may contact our Approvals and Permits Division at (202) 366-4535 for more information.

I hope this satisfies your inquiry. Please contact us if we can be of further assistance.

Sincerely,

 

T. Glenn Foster
Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division

173.304, 173.22, 173.306,173.314, 173.315

Regulation Sections

Section Subject
107.105 Application for special permit
172.101 Purpose and use of hazardous materials table
173.22 Shipper's responsibility
173.304 Filling of cylinders with liquefied compressed gases
173.306 Limited quantities of compressed gases