46 CFR § 151.56-1
Prohibited materials
April 15, 2021
When one of the following paragraphs of this section is referenced in table 151.05, the materials listed in that paragraph may not be used in components that contact the cargo or its vapor:
(a) Aluminum or aluminum alloys.
(b) Copper or copper alloys.
(c) Zinc, galvanized steel, or alloys having more than 10 percent zinc by weight.
(d) Magnesium.
(e) Lead.
(f) Silver or silver alloys.
(g) Mercury.
[CGD 88-100, 54 FR 40041, Sept. 29, 1989]