USA Banner

Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

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

Interpretation Response #10-0091 ([Mr. Juan Gonzalez])

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. Juan Gonzalez

Country: US

View the Interpretation Document

Response text:

October 20, 2010



Mr. Juan Gonzalez

Calle 29 # 17 B 100 Casa 4

El Retiro - Antioquia


Reference No. 10-0091

Dear Mr. Gonzalez:

This is in response to your request for clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to certain cylinder marking requirements. Your questions are paraphrased and answered below.

Q1. Section 173.301(b) (Note: your e-mail refers to the out-of-date cite, § 173.34. The information was moved to § 173.301 in a final rule, "Hazardous Materials: Requirements for Maintenance, Requalification, Repair and Use of DOT Specification Cylinders," HM-220D, 67 FR 51652, published August 8, 2002.) states that additional information may be marked on the cylinder provided it does not affect the required markings prescribed in the applicable cylinder specification. What type of additional information is referred to in this statement?

A1. Section 173.301(b) refers to any information that is not required. The non-required additional information may not diminish or obstruct the required information. In addition,

§ 178.35(f) addresses additional marking requirements for specification cylinders. Additional markings include those that are not required in Part 180 of Subpart C and

§ 178.35(f).

Q2. Who is authorized to place information on the cylinder?

A2. The application of requalification markings required under the HMR are only authorized by individuals meeting the requirements of Part 107, Subpart I, "Approval of Independent Inspection Agencies, Cylinder Requalifiers, and Non-domestic Chemical Analyses and Tests of DOT Specification Cylinders."

Q3. Is the indentation of new information over the surface where original information was initially stamped acceptable?

A3. Requalification markings must conform to requirements in § 180.213, including maintaining the minimal wall thickness and specifications for the marking size and location. Generally, all specification markings must be maintained, legible, and visible at all times. Previous requalification markings may not be obliterated except as provided in § 180.213(b)(2).

I hope this information is helpful. Please contact this office should you have additional questions.


T. Glenn Foster

Chief, Regulatory Review and Reinvention

Office of Hazardous Materials Standards

173.301, 178.35(f), 180.213

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
180.213 Requalification markings