46 CFR § 153.436
Heat transfer fluids: compatibility with cargo
April 15, 2021
A heat transfer fluid separated from the cargo by only one wall (for example, the heat transfer fluid in a coil within a tank) must be compatible with the cargo under the standards prescribed for compatibility between two cargoes in Part 150 of this chapter.
[CGD 81-078, 50 FR 21174, May 22, 1985]