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Interpretation Response #11-0158 ([Corrosion Testing Laboratories, Inc.] [Mr. Bradley D. Krantz])

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

Interpretation Response Details

Response Publish Date:

Company Name: Corrosion Testing Laboratories, Inc.

Individual Name: Mr. Bradley D. Krantz

Location State: DE Country: US

View the Interpretation Document

Response text:

April 23, 2012









Mr. Bradley D. Krantz

V.P. of Laboratory Services

Corrosion Testing Laboratories, Inc.

60 Blue Hen Drive

Newark, DE   19713


Ref. No. 11-0158


Dear Mr. Krantz:


This responds to your June 28, 2011 request for clarification on § 173.137(c)(2) of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180).  Specifically, you ask if you are to use only the corrosion rate criterion stated in § 173.137 for determining metal corrosivity or are you to use both the corrosion rate and the localized corrosion rate criteria of the UN Method.


You may use the UN Manual of Tests and Criteria or other equivalent methods.  In a final rule published December 20, 2004 under Docket HM-215G (69 FR 76155), we revised the language in § 173.137 (c)(2) mandating the corrosion test in the UN Manual of Tests and Criteria as the only acceptable test method for determining the corrosivity of a material. That was not our intent.  In a final rule published December 29, 2006 under Docket HM-215I (71 FR 78596), we revised the language in  § 173.137(c)(2) to specify that corrosivity may be determined in accordance with methods described in the UN Manual of Tests and Criteria, as well as other equivalent methods, such as those described in ASTM G 31-72.


I hope this answers your inquiry.  If you need additional assistance, please contact this office at (202) 366-8553.






Ben Supko

Acting Chief, Standards Development Branch

Standards and Rulemaking Division



Regulation Sections

Section Subject
173.137 Class 8-Assignment of packing group