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 #20-0094

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

Interpretation Response Details

Response Publish Date:

Company Name: Stabilis Solutions

Individual Name: Mr. Vignesh Pandurengan

Location State: TX Country: US

View the Interpretation Document

Response text:

May 28, 2021

Mr. Vignesh Pandurengan
Maintenance Specialist
Stabilis Solutions
10375 Richmond Avenue, Suite 700
Houston, TX  77042

Reference No. 20-0094

Dear Mr. Pandurengan:

This is in response to your December 7, 2020, email and subsequent conversation with a member of my staff requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to a Department of Transportation (DOT) cargo tank motor vehicle (CTMV). Specifically, you ask whether an insulated MC 338 CTMV transporting non-corrosive materials and equipped with manholes must undergo an internal visual inspection within certain time intervals.

The answer is no. Section 180.407(c) excepts DOT Specification MC 338 cargo tanks from the internal visual inspection requirement when transporting non-corrosive materials. However, MC 338 cargo tanks are required to be externally inspected annually. If the insulation of the MC 338 CTMV cargo tank you describe is found to preclude a complete external inspection, the cargo tank would be required to be internally inspected in order to complete the external inspection requirements found in §§ 180.407(c) and 180.407(d). In addition, because the cargo tank you describe is equipped with manholes, Note 4 of § 180.407(c) would apply, and a hydrostatic or pneumatic pressure test may be performed in place of the internal inspection.

I hope this information is helpful. Please contact us if we can be of further assistance.


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

180.407(c), 180.407(d)

Regulation Sections

Section Subject
180.407 Requirements for test and inspection of specification cargo tanks