Based on eight (8) recent enforcement investigations, conducted by the U.S. Department of Transportation, Pipeline and Hazardous Materials Safety Administration (PHMSA), Office of Hazardous Materials Enforcement (OHME), this letter is intended to notify the industry of serious safety problems and non-compliance issues regarding the maintenance, filling, transport and use of nurse tanks in anhydrous ammonia service. PHMSA is greatly concerned with the lack of compliance and understanding of the minimum safety requirements for nurse tanks based on its investigations. PHMSA recognizes the breadth of the nurse tank industry. In order to magnify its safety and compliance efforts, PHMSA feels this letter will help increase awareness and provide a means of contact for questions about the prescribed safety requirements.
In all of the investigations, PHMSA Hazmat Investigators noted a similar pattern of non-compliance and safety problems. Below is a list of the areas of non-compliance and safety problems. A nurse tank, by US DOT regulatory definition, is a cargo tank considered an implement of husbandry for the transportation of bulk anhydrous ammonia.
Under an exception in 49 CFR § 173.315(m) in the Hazardous Materials Regulations (HMR), the transportation of anhydrous ammonia in a “nurse tank” is only authorized if the tank is operated by a private carrier and used exclusively for agricultural purposes. This section also excepts a “nurse tank” from meeting the specification requirements for packaging in the (HMR). However, a nurse tank must meet the general requirements of § 173.24 and the specific criteria outlined in §173.315(m) (below).
§ 173.315(m) Requirements
The tank must:
(1) Have a minimum design pressure of 250 psig and meets the requirements of the edition of Section VIII of the ASME Code in effect at the time it was manufactured and marked.
(2) Be equipped with safety relief valves meeting the requirements of CGA pamphlet S1.2.
(3) Be painted white or aluminum.
(4) Have a capacity of 3,000 gallons or less.
(5) Be loaded to a filling density no greater than 56 percent.
(6) Be securely mounted on a farm wagon.
(7) Be in conformance with the requirements of part 172 of this subchapter except that shipping papers are not required; and it need not be marked or placarded on one end if that end contains valves, fittings, regulators or gauges when those appurtenances prevent the markings and placard from being properly placed and visible.
All of the requirements listed in § 173.315(m) must be followed for the regulatory exception to apply, otherwise the full requirements of the HMR apply for specification containers, hazard communication, and paperwork, training and carrier specific requirements.
CLICK HERE to see the full alert.