This list contains materials identified either by proper shipping name in 49 CFR 172.101 or shipped under an “n.o.s.” shipping description that, under certain conditions, can corrode carbon steel tanks or service equipment at a rate that may reduce the design level of reliability and safety of the tank or equipment to an unsafe level before the next qualification. Materials identified on this list are considered corrosive to the tank or service equipment.

While every effort was made to identify materials deemed corrosive to the tank or service equipment, owners and operators are cautioned that this list may not be inclusive. Tank car owners and operators are reminded of their duty to ensure that no in-service tank will deteriorate below the specified minimum thickness requirements in this subchapter. See § 180.509(f)(3). In addition, FRA states a tank car owner must designate an internal coating or lining appropriately based on its knowledge of the chemical and not rely simply on this list. Regarding future thickness tests, this list may also be modified based on an analysis of the test results by the car owner, the Department of Transportation, or the Association of American Railroads' Tank Car Committee.

Hazardous Materials Table Proper Shipping Names (See § 172.101) Acetic acid, glacial or Acetic acid solution Aluminum chloride, solution Arsenic acid, liquid Arsenic acid, solid Butyric acid Ferric chloride, solution Fertilizer ammoniating solution (Nitrogen fertilizer solution) Fluoroboric acid Fluorosilicic acid Formaldehyde, solutions, flammable Formaldehyde, solutions Hydrobromic acid Hydrochloric acid Hydrochloric acid solution Hydrofluoric acid and Sulfuric acid mixtures Hydrofluoric acid Hydrogen peroxide and peroxyacetic acid mixtures, stabilized Hydrogen, peroxide, aqueous solutions Hydrogen peroxide, stabilized or Hydrogen peroxide aqueous solutions, stabilized Hypochlorite solutions Nitric acid Phenyl phosphorus dichloride Phenyl phosphorus thiodichloride Phosphoric acid solution Phosphoric acid, solid Phosphorus trichloride (Phosphorus chloride) Sodium chlorate Sodium chlorate, aqueous solution Sodium hydrosulfide Sulfur, molten Sulfuric acid Sulfuric acid, fuming Sulfuric acid, spent Zinc chloride, anhydrous Zinc chloride, solution Materials Transported Under an “N.O.S.” Description Benzoic acid (Environmentally hazardous substance, liquid, n.o.s., (RQ 5,000 pounds) Bisulphites, aqueous solution, n.o.s. (Ammonium bisulfide) Black liquor (Corrosive liquids, n.o.s. (contains sulfuric acid)) Calcium lignosulfonate (not regulated under this subchapter) Hexanoic acid (Corrosive liquids, n.o.s. (contains hexanoic acid)) Lignin liquor (not regulated under this subchapter) Lithium chloride (not regulated under this subchapter) Sodium polyacrylate (not regulated under this subchapter) Titanium sulfate solution (Corrosive liquids, n.o.s. (contains sulfuric acid)) White liquor (not regulated under this subchapter) [77 FR 37991, June 25, 2012]