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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 #21-0015

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

Interpretation Response Details

Response Publish Date:

Company Name: Iowa Dept. of Transportation

Individual Name: Robert Johnson

Location State: IA Country: US

View the Interpretation Document

Response text:

April 15, 2021

Robert Johnson
Captain
Iowa Dept. of Transportation
6310 SE Convenience Blvd.
Ankeny, IA 50021

Reference No. 21-0015

Dear Mr. Johnson:

This letter is in response to your February 10, 2021, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to anhydrous ammonia transported in nurse tanks. pecifically, you state that inspection officers from the Iowa Department of Transportation (DOT) have encountered carriers transporting anhydrous ammonia (NH3) nurse tanks on flatbed motor vehicles and you ask questions regarding the applicability of provisions found in § 173.315(m) when these nurse tanks are in transportation.

Additionally, you describe two scenarios where a person (e.g., a private motor carrier versus a for-hire motor carrier) is transporting anhydrous ammonia (NH3) nurse tanks that are not cleaned or purged and you provide two photographs as examples:

  • Photograph #1: Illustrates a “nurse tank” attached to a farm wagon with wheels removed and secured on a flatbed motor vehicle.
  • Photograph #2: Illustrates a “nurse tank” attached to a farm wagon with wheels attached and secured on a flatbed motor vehicle.

We have paraphrased and answered your questions as follows:

Scenario #1: A private motor carrier (e.g., a farmer) purchases an anhydrous ammonia (NH3) nurse tank that is not cleaned and purged and transports it to their farm for agricultural operations.

Q1. You ask whether the cargo tank shown in photograph #1 is considered to be a "nurse tank" in accordance with § 173.315(m), provided it meets all applicable requirements of that paragraph.

A1. Based on the scenario you provided and the cargo tank shown in photograph #1, it is the opinion of this Office that it would not meet the conditions that would allow for a non-DOT specification cargo tank carrying anhydrous ammonia (NH3) to be transported under § 173.315(m). Specifically, it appears the transport does not conform to the conditions of § 173.315(m)(3)(iii), which restricts the nurse tank to rural roads in areas within 50 miles of the fertilizer distribution point. Please note that securely mounting a nurse tank to a farm wagon and then placing that farm wagon on a flatbed motor vehicle is not an acceptable means to comply with the requirements in § 173.315(m)(1) through (m)(3).

Q2. You ask whether the cargo tank and/or motor vehicle in photograph #1 meet the requirements of §§ 173.315(m)(1) introductory text, 173.315(m)(1)(vi), or 173.315(m)(3).

A2. The answer is no, see answer A1.

Q3. You ask whether the cargo tank shown in photograph #2 is considered to be a "nurse tank" in accordance with § 173.315(m), provided it meets all applicable requirements of that paragraph.

A3. The answer is no, see answer A1.

Q4. You ask whether the cargo tank and/or motor vehicle in photograph #2 meet the requirements of §§ 173.315(m)(1) introductory text, 173.315(m)(1)(vi), or 173.315(m)(3).

A4. The answer is no, see answer A1.

Q5. You ask whether a tank may be defined as a "nurse tank" if the tank used to transport anhydrous ammonia (NH3) cannot meet the applicable requirements in § 173.315(m).

A5. "Nurse tank" is a common term to describe a tank used in husbandry for purposes of transporting agricultural chemicals. The term "nurse tank" has no defined meaning in the HMR and is not specifically defined in § 171.8. Rather, the HMR outline conditions under which a non-DOT specification cargo tank may be used to transport anhydrous ammonia (NH3) and those provisions address husbandry operations that use such a tank. In accordance with § 173.315(m)(1), a cargo tank is excepted from specification requirements if it is an implement of husbandry for transporting anhydrous ammonia (NH3) and is operated by a private motor carrier (e.g., farmer) exclusively for agricultural purposes. Therefore, if a non-DOT specification cargo tank does not meet the conditions of § 173.315(m), a private motor carrier must represent the non-DOT specification cargo tank as "empty" (see § 173.29(b)) or must obtain a special permit to transport the anhydrous ammonia (NH3) in the cargo tank.

Q6. You ask whether a private motor carrier is subject to HMR requirements for the transportation of anhydrous ammonia (NH3) if a “nurse tank” is unable to meet any of the conditions in § 173.315(m).

A6. The answer is yes. If any of the stated conditions in § 173.315(m) are not met, the private motor carrier is subject to the HMR.

Scenario #2: A for-hire motor carrier (e.g., a contractor) transports an anhydrous ammonia (NH3) nurse tank that is not cleaned and purged.

Q7. You ask whether these tanks are eligible for the provisions found in § 173.315(m)(1) through (m)(3) if it can be confirmed that the for-hire motor carrier (i.e., contractor) is transporting the cargo tanks containing anhydrous ammonia (NH3) to a farm for agricultural purposes.

A7. The answer is no. Hiring a contractor renders the transportation of these cargo tanks as being no longer in private transportation exclusively for agricultural purposes in accordance with § 173.315(m) introductory text.

Q8. You ask whether these tanks would be eligible for the provisions found in § 173.315(m)(1) through (m)(3) if a for-hire motor carrier transported them to a general commercial location (e.g., equipment dealer).

A8. The answer is no, see answer A7.

Q9. You ask whether there is an instance when a for-hire motor carrier, who transports anhydrous ammonia (NH3) in nurse tanks, is eligible for the provisions in § 173.315(m)(1) through (m)(3)?

A9. The answer is no, see answer A7.

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

Sincerely,

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

171.8, 173.29(b), 173.315(m), 173.315(m)(3)(iii), 173.315(m)(1), 173.315(m)(2), 173.315(m)(3), 173.315(m)(1)(vi)

Regulation Sections

Section Subject
171.8 Definitions and abbreviations
173.29 Empty packagings
173.315 Compressed gases in cargo tanks and portable tanks