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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 #19-0089

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

Interpretation Response Details

Response Publish Date:

Company Name: Uniweld Products, Inc.

Individual Name: Janet Beets

Location State: FL Country: US

View the Interpretation Document

Response text:

January 30, 2020

Janet Beets
Uniweld Products, Inc.
2850 Ravenswood Road
Fort Lauderdale, FL  33312

Reference No. 19-0089

Dear Ms. Beets:

This letter is in response to your June 20, 2019, letter and August 28, 2019, phone conversation requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to marking requirements. Specifically, you provide an example of the markings on a strong outer packaging in reference to the following scenario:

  • Uniweld Products, Inc. offers propane and propylene for transportation in DOT specification 39, non-refillable steel cylinders, further packaged in a strong outer packaging (as required in DOT Special Permit (DOT-SP) 13318).
  • The packaging configuration is either 24 propylene cylinders, 24 propane cylinders, or 12 propylene and 12 propane cylinders.
  • The packages are only transported via highway.
  • The strong outer packaging is marked with the following: "IMO 2.1," "Inside Packages Comply with DOT.SP 13318," "OVERPACKED," "UN 1075 Petroleum Gases Liquified," and "UN 1077 Propylene." Furthermore, there are check boxes next to "UN 1075 Petroleum Gases Liquified" and "UN 1077 Propylene" that will be checked-off based on the presence of the material in the outer packaging.

We have paraphrased and answered your questions as follows:

Q1. You ask whether the strong outer packaging may display a check box next to both "UN1075, Petroleum Gases Liquefied" and "UN1077, Propylene" for purposes of indicating the presence of one or both hazardous materials.

A1. The answer is no. In accordance with § 172.303(a), no person may offer for transportation a package that is marked with the proper shipping name, the UN identification number of a hazardous material, or any other markings indicating that the material is hazardous unless the package contains the identified hazardous material or its residue. Therefore, when the package contains only propylene or only propane, the package may not display the UN identification number and proper shipping name of the hazardous material that is not present in the package. If both UN identification numbers and proper shipping names are pre-printed on the strong outer packaging, the UN identification number and proper shipping name of the hazardous material not present in the package must be securely covered or voided in some manner to avoid confusion that the material is present.

Q2. You ask whether the strong outer packaging may display the text "IMO 2.1."

A2. The answer is yes. Please note that the HMR does not require the hazard classification (i.e., 2.1) to be marked on the packaging.

However, an indication of the International Maritime Organization (IMO) classification may cause confusion or frustration of your shipment in transportation. More specifically, "IMO" may be perceived as an indication that your package is prepared for vessel transportation in accordance with the International Maritime Dangerous Goods (IMDG) Code.

Q3. You ask whether the strong outer packaging may display the text "INSIDE PACKAGES COMPLY WITH DOT.SP 13318."

A3. The answer is no. Paragraph 7.b.(3) of DOT-SP 13318 requires the outside of each outer packaging be marked "Inside package conforms to DOT-SP 13318." Since the text provided in your request differs from the required text in the special permit, the marking does not comply with the conditions of the special permit. The package should be marked with the text as directed in DOT-SP 13318.

Q4. You ask whether the strong outer packaging may display the text "OVERPACKED."

A4. The answer is no. Section 171.8 of the HMR defines an overpack to mean "an enclosure that is used by a single consignor to provide protection or convenience in handling of a package or to consolidate two or more packages." Because DOT-SP 13318 requires the use of a strong outer packaging (see paragraph 7.b.(1)), the marked packaging in your request does not meet the definition of an overpack. Therefore, "OVERPACKED" is not an appropriate marking for your shipment.

Please note that if your outer packaging met the definition of an overpack, the word "OVERPACK" is required to be marked on the outside of an overpack when specification packaging is required, unless the required marking representative of each package type contained in the overpack is visible from outside of the overpack (see § 173.25(a)(4)). The addition of the "-ED" at the end of the word "OVERPACK" is not authorized.

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


Dirk Der Kinderen
Chief, Standards Development Branch
Standards and Rulemaking Division

172.303(a), 171.8, 173.25(a)(4)

Regulation Sections

Section Subject
171.8 Definitions and abbreviations
172.303 Prohibited marking
173.25 Authorized packagings and overpacks