United States v. International Minerals & Chemical Corp.

Supreme Court of the United States · 1971 · Criminal Law

402 U.S. 558 (1971)

Updated July 29, 2026

Criminal LawMens reaIgnorance of the lawRegulatory crimesHazardous materials transportationknowinglyignorance of lawregulations

Facts

The information charged appellee with shipping sulfuric acid and hydrofluosilicic acid in interstate commerce and knowingly failing to show on the shipping papers the required classification, "Corrosive Liquid," as required by 49 C.F.R. § 173.427. Under 18 U.S.C. § 834(a), the regulatory agency had authority to issue safe transportation regulations for corrosive liquids, and § 834(f) imposed criminal penalties on anyone who knowingly violated such regulations. The District Court dismissed the information on the view that it failed to allege a knowing violation in the sense required by the statute. The Supreme Court treated the sole question as whether the statute required knowledge of the regulation itself, in addition to knowledge of the shipment of dangerous materials.

Issue

When 18 U.S.C. § 834(f) punishes whoever "knowingly violates" a hazardous-material transportation regulation, must the government prove that the defendant knew the regulation's requirements, or is it enough to prove knowledge of the facts constituting the violation, such as the shipment of dangerous acids?

Rule

Under 18 U.S.C. § 834(f), "knowingly" requires knowledge of the facts that make the conduct fall within the regulation, not knowledge of the regulation itself. The general rule that ignorance of the law is no excuse applies equally to duly promulgated and published regulations, and when dangerous or deleterious products are involved, a person aware he is dealing with them is presumed to be aware of regulation.

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One of 10 multiple-choice questions for this case. Pick an answer to see why.

Ridgeway Solvents, a small manufacturer in Toledo, ships drums of nitric acid to a customer in Indiana. Lena Ortiz, the shipping manager, knows the drums contain nitric acid but omits the required hazard classification from the shipping papers because she has never read the transportation regulations.

If Lena is prosecuted under a statute punishing anyone who knowingly violates duly promulgated hazardous-material shipping regulations, which is the strongest argument for conviction?

Explanation. The majority held that when dangerous or deleterious materials are involved, 'knowingly' requires knowledge of the facts constituting the violation—here, that the defendant was shipping dangerous acid—not knowledge of the specific regulation. Ignorance of a duly promulgated regulation is no defense.