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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 #15-0184 ([The Chemours Company] [Mr. Randolph Martin])

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

Interpretation Response Details

Response Publish Date:

Company Name: The Chemours Company

Individual Name: Mr. Randolph Martin

Location State: DE Country: US

View the Interpretation Document

Response text:

January 21, 2016

Mr. Randolph Martin
Senior Consultant, Hazardous Materials Distribution
The Chemours Company
1007 Market St., Rm 2024
Wilmington, DE 19899

Ref. No.: 15-0184

Dear Mr. Martin:

This is in response to your e-mail dated September 10, 2015 requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) relating to requalification of Department of Transportation (DOT) specification cylinders.  You state that you use DOT-3AL2216 cylinders in escape packs that stay on-site and are not offered for transportation off-site.  Your questions are paraphrased and answered as follows:

Q1.  Since these cylinders are not offered for transportation of hazardous materials, are they required to be requalified?

A1.  In accordance with § 180.3(a), a cylinder marked to certify that it conforms to the requirements of the HMR must be maintained in accordance with applicable specification requirements whether or not it is in transportation in commerce at any particular time.  Please see the responses to Q3 and Q4 below noting variances from this requirement.   

Q2.  If requalification is required, what is the frequency?

A2.  DOT 3AL cylinders (excluding cylinders used as fire extinguishers under
§ 180.209(j)) must be requalified every 5 years per “Table 1- Requalification of Cylinders”.  If applicable DOT 3AL manufactured of 6351-T6 aluminum alloy cylinders must also be requalified and inspected for sustained load cracking in accordance with the non-destructive method described in the “Requalification and Inspection of DOT-3AL Cylinders Made of Aluminum Alloy 6351-T6” table in § 180.209(m).

Q3.  If the cylinders (that were filled prior to the date their requalification becomes due) require requalification, is such requalification only required once the cylinders are emptied and is there a time limit on how long the cylinders can stay in service before they must be requalified?

A3. Sections 173.301(a)(6) and 180.205(c) both state that a cylinder filled (i.e., charged) before its requalification becomes due may remain in service until it is emptied, and may be transported in commerce by highway, rail, aircraft, or vessel provided all applicable HMR requirements are met.  There is no time limit on how long charged cylinders can stay in service before they must be requalified under the HMR.  However, there may be differing requirements for cylinders used in certain applications by other federal agencies.  After emptying, a cylinder due for requalification may not be refilled and offered for transportation unless it has been requalified in accordance with Part 180, Subpart C of the HMR.  A cylinder with a specified service life may not be refilled and offered for transportation after its authorized service life has expired.  

Q4. If we were to cover, remove, or obliterate the DOT specification markings then requalification is not required as the cylinders are no longer being represented as DOT specification cylinders.

A4. Your understanding is correct. Covering, removing, or obliterating the DOT specification markings on your cylinders would mean requalification would not be required.  However, we note that there is no requirement to requalify the cylinder until it is emptied (see A3 above).  If you chose to remove the marking, care should be taken when removing the markings to ensure the minimum required thickness of the cylinder is maintained.  It should also be noted that removal of DOT specification markings would also invalidate authorized transportation of the cylinder.

Q5. Please confirm that if §§ 173.301(a)(6) and 180.205(c) both apply, that our cylinders filled before the requalification due date can continue in service until emptied, and can be filled at any time before the requalification is due.  After the requalification date the cylinders must be requalified before refilling.

A5.  Yes (see A3 above).

I trust this information is helpful.  If you have further questions, please do not hesitate to contact this office.


Duane A. Pfund
International Standards Coordinator
Standards and Rulemaking Division

180.3(a), 180.209(j), 180.209(m), 173.301(a)(6), 180.205(c)

Regulation Sections

Section Subject
173.301 General requirements for shipment of compressed gases and other hazardous materials in cylinders, UN pressure receptacles and spherical pressure vessels
180.205 General requirements for requalification of specification cylinders
180.209 Requirements for requalification of specification cylinders
180.209 Requirements for requalification of specification cylinders
180.3 General requirements