Interpretation Response #25-0084
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: Texas Department of Public Safety
Individual Name: Dustin Henderson
Location State: TX Country: US
View the Interpretation Document
Response text:
December 8, 2025
Dustin Henderson
CVE-Corporal IV
Radiation/Nuclear Threat Detection Unit
Texas Department of Public Safety
1600 West Loop 306
San Angelo, TX 76904
Reference No. 25-0084
Dear Mr. Henderson:
This letter is in response to your June 23, 2025 email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to bulk containers commonly known in industry as "frac tanks." Specifically, you ask for clarification regarding the use of frac tanks for the transportation of "NA1993, Diesel fuel, 3, Packing Group (PG) III."
We have paraphrased and answered your questions as follows:
Q1. Does a frac tank meet the definition of a portable tank in accordance with § 171.8?
A1. No. Frac tanks do not meet the definition of a portable tank and the term "frac tank" is not defined in § 171.8. In addition, the pictures provided in the initial request do not display the characteristics (e.g., skids, mountings) to identify these packagings as portable tanks; however, they may qualify as non-DOT specification cargo tank motor vehicles.
Q2. If a frac tank meets the definition of a portable tank, is "NA1993, Diesel fuel, 3, PG III" authorized for transport in a frac tank in accordance with § 173.241(c)?
A2. Frac tanks do not meet the definition of a portable tank; however, "NA1993, Diesel fuel, 3, PG III" may be transported in a non-DOT specification cargo tank motor vehicle suitable for the transport of liquids. It is the offeror's responsibility to determine the flash point of the hazardous material, package compliance, and all requirements of the HMR are met prior to the shipment being offered for transportation.
Q3. Can "NA1993, Diesel fuel, 3, PG III" be transported in a frac tank as residue?
A3. Yes. An empty packaging containing only the residue of a hazardous material shall be offered for transportation and transported in the same manner as when it previously contained a greater quantity of that hazardous material.
Q4. Can "NA1993, Diesel fuel, 3, PG III" be transported in a frac tank, while the frac tank is located on a trailer?
A4. Yes. The HMR does not prohibit frac tanks from being transported on trailers. However, it is the offeror's responsibility to ensure the hazardous material is properly classified, and the package is offered for transportation in accordance with the HMR.
Q5. Would a frac tank qualify as a "tank" for purposes of a commercial driver's license and require the driver to obtain an endorsement?
A5. The endorsement requirements for a commercial driver's license (CDL) are under the purview of the Federal Motor Carrier Safety Administration (FMCSA)-see 49 CFR Part 383. FMCSA is the lead Federal government agency responsible for regulating and providing safety oversight of commercial motor vehicles. You may wish to contact the FMCSA regarding clarification of any applicable CDL endorsement requirements.
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
Dirk DerKinderen
Chief, Standards and Development Branch
Standards and Rulemaking Division
§ 171.8, § 172.102(c)(3), § 173.29, § 173.241(c)