46 C.F.R. § 153.239
Use of cast iron
(a) Cast iron used in a cargo containment system must meet the requirements of § 56.60-10(b) of this chapter.
(b) For purposes of this section, the term “lethal products” in § 56.60-10(b) means those cargoes that Table 1 references to § 153.525 or § 153.527.