33 CFR § 159.117 - Chemical resistance test.
(a) In each case where the recognized facility doubts the ability of a material to withstand exposure to the substances listed in paragraphs (b) and (c) of this section a sample of the material must be tested.
(b) A sample referred to in paragraph (a) of this section must be partially submerged in each of the following substances for 100 hours at an ambient temperature of 22 °C.
(2) Any disinfectant that is required in the operation of the device.
(3) Any chemical compound in solid, liquid or gaseous form, used, emitted or produced in the operation of the device.
(4) Fresh or salt (3.5 percent Sodium Chloride) flush water.
(5) Toilet bowl cleaners.
(6) Engine Oil (SAE/30).
(7) Ethylene Glycol.
(8) Detergents (household and bilge cleaning type).
(c) A sample of the material must be doused 20 times, with a 1 hour drying period between dousings, in each of the following substances:
(2) Diesel fuel.
(3) Mineral spirits.
(5) Methyl alcohol.