This fact sheet is intended to provide guidance to the agricultural anhydrous ammonia regulated community regarding anhydrous ammonia storage vessels with missing or illegible data plates. It is not intended to enact policy for the Missouri Department of Natural Resources, nor does it serve as a way for determining compliance with state or federal regulatory requirements.
The Compressed Gas Association Standard CGA G-2.1-2023 – Requirements for the Storage and Handling of Anhydrous Ammonia–7th Edition states that anhydrous ammonia storage vessels with missing or illegible data plates that are not replaceable through the manufacturer, must be inspected or removed from service by Jan. 1, 2030. The inspection criteria cited in the CGA are as follows:
- Wall thickness of the container shell and heads in inches or millimeters
- Water capacity of the container in pounds, kilograms, gallons or cubic meters at 60 degrees Fahrenheit
- Outside surface area of the container in square feet or square meters
Relocating an existing storage vessel must meet the data plate requirements and construction rules listed in the CGA. Facilities should refer to the decision tree below for guidance. If a facility determines the storage vessel does not meet relevant codes, the following tests are required:
- Testing for weld defects
- Wall thickness of the container shell and heads in inches or millimeters
The department interpretation of this requirement is that a storage container with missing or illegible data plates may continue to be used beyond Jan. 1, 2030, if an inspection meeting the above criteria is performed. Facilities with anhydrous ammonia tanks that have missing or illegible data plates should contact the department's Agricultural Anhydrous Ammonia Unit for information about the inspection process.