opinion: UNITED STATES v. INTERNATIONAL MINERALS & CHEMICAL CORP.
  No. 557.
  Argued April 26, 1971
  Decided June 1, 1971
  Douglas, J., delivered the opinion of the Court, in which Burger, C. J., and Black, White, Marshall, and Blackmun, JJ., joined. Stewart, J., filed a dissenting opinion, in which HarlaN and Bren-NAN, JJ., joined, post, p. 565.
  John F. Dienelt argued the cause for the United States pro hac vice. With him on the briefs were Solicitor General Griswold, Assistant Attorney General Wilson, and Beatrice Rosenberg.
  Harold E. Spencer argued the cause for appellee. With him on the brief was Charles J. McCarthy.
  Mr. Justice Douglas
  delivered the opinion of the Court.
  The information charged that appellee shipped sulfuric acid and hydrofluosilicic acid in interstate commerce and “did knowingly fail to show on the shipping papers the required classification of said property, to wit, Corrosive Liquid, in violation of 49 C. P. R. 173.427.”
  Title 18 U. S. C. § 834 (a) gives the Interstate Commerce Commission power to “formulate regulations for the safe transportation” of “corrosive liquids” and 18 U. S. C. § 834 (f) states that whoever “knowingly violates any such regulation” shall be fined or imprisoned.
  Pursuant to the power granted by § 834 (a) the regulatory agency promulgated the regulation already cited which reads in part:
  “Each shipper offering for transportation any hazardous material subject to the regulations in this chapter, shall describe that article on the shipping paper by the shipping name prescribed in § 172.5 of this chapter and by the classification prescribed in § 172.4 of this chapter, and may add a further description not inconsistent therewith. Abbreviations must not be used.” 49 CFR § 173.427.
  The District Court, relying primarily on Boyce Motor Lines, Inc. v. United States, 342 U. S, 337, ruled that the information did not charge a “knowing violation” of the regulation and accordingly dismissed the information.
  The United States filed a notice of appeal to the Court of Appeals, 18 U. S. C. § 3731, and in reliance on that section later moved to certify the case to this Court which the Court of Appeals did; and we noted probable jurisdiction, 400 U. S. 990.
  Here as in United States v. Freed, 401 U. S. 601, which dealt with the possession of hand grenades, strict or absolute liability is not imposed; knowledge of the shipment of the dangerous materials is required. The sole and narrow question is whether “knowledge” of the regulation is also required. It is in that narrow zone that the issue of “mens rea” is raised; and appellee bears down hard on the provision in 18 U. S. C. § 834 (f) that whoever “knowingly violates any such regulation” shall be fined, etc.
  Boyce Motor Lines, Inc. v. United States, supra, on which the District Court relied, is not dispositive of the issue. It involved a regulation governing transporting explosives, inflammable liquids, and the like and required drivers to “avoid, so far as practicable, and, where feasible, by prearrangement of routes, driving into or through congested thoroughfares, places where crowds are assembled, street car tracks, tunnels, viaducts, and dangerous crossings.” The statute punished whoever “knowingly” violated the regulation. Id., at 339. The issue of “mens rea” was not raised below, the sole question turning on whether the standard of guilt was unconstitutionally vague. Id., at 340. In holding the statute was not void for vagueness we said:
  “The statute punishes only those who knowingly violate the Regulation. This requirement of the presence of culpable intent as a necessary element of the offense does much to destroy any force in the argument that application of the Regulation would be so unfair that it must be held invalid. That is evident from a consideration of the effect of the requirement in this case. To sustain a conviction, the Government not only must prove that petitioner could have taken another route which was both commercially practicable and appreciably safer (in its avoidance of crowded thoroughfares, etc.) than the one it did follow. It must also be shown that petitioner knew that there was such a practicable, safer route and yet deliberately took the more dangerous route through the tunnel, or that petitioner willfully neglected to exercise its duty under the Regulation to inquire into the availability of such an alternative route.
  “In an effort to give point to its argument, petitioner asserts that there was no practicable route its trucks might have followed which did not pass through places they were required to avoid. If it is true that in the congestion surrounding the lower Hudson there was no practicable way of crossing the River which would have avoided such points of danger to a substantially greater extent than the route taken, then petitioner has not violated the Regulation. But that is plainly a matter for proof at the trial. We are not so conversant with all the routes in that area that we may, with no facts in the record before us, assume the allegations of the indictment to be false. We will not thus distort the judicial notice concept to strike down a regulation adopted only after much consultation with those affected and penalizing only those who knowingly violate its prohibition.” Id., at 342-343.
  The “mens rea” that emerged in the foregoing discussion was not knowledge of the regulation but knowledge of the safer routes and those that were less safe within the meaning of the regulation. Mr. Justice Jackson, writing in dissent for himself, Mr. Justice Black, and Mr. Justice Frankfurter, correctly said:
  “I do not suppose the Court intends to suggest that if petitioner knew nothing of the existence of such a regulation its ignorance would constitute a defense.” 342 U. S., at 345.
  There is no issue in the present case of the propriety of the delegation of the power to establish regulations and of the validity of the regulation at issue. We therefore see no reason why the word “regulations” should not be construed as a shorthand designation for specific acts or omissions which violate the Act. The Act, so viewed, does not signal an exception to the rule that ignorance of the law is no excuse and is wholly consistent with the legislative history.
  The failure to change the language in § 834 in 1960 should not lead to a contrary conclusion. The Senate approved an amendment deleting “knowingly” and substituting therefor the language “being aware that the Interstate Commerce Commission has formulated regulations for the safe transportation of explosives and other dangerous articles.” But the House refused to agree. As the House Committee stated, its version would “retain the present law by providing that a person must ‘knowingly’ violate the regulations.”
  The House Committee noted there was a “judicial pronouncement as to the standards of conduct that make a violation a ‘knowing’ violation.” In St. Johnsbury Trucking Co. v. United States, 220 F. 2d 393, 397, Chief Judge Magruder had concluded that knowledge of the regulations was necessary. But whether the House Committee was referring to Boyce Motor Lines or the opinion of Chief Judge Magruder is not clear since both views of the section were before Congress. It is clear that strict liability was not intended. The Senate Committee felt it would be too stringent and thus rejected the position of the Interstate Commerce Commission. But despite protestations of avoiding strict liability the Senate version was very likely to result in strict liability because knowledge of the facts would have been unnecessary and anyone involved in the business of shipping dangerous materials would very likely know of the regulations involved. Thus in rejecting the Senate version the House was rejecting strict liability. But it is too much to conclude that in rejecting strict liability the House was also carving out an exception to the general rule that ignorance of the law is no excuse.
  The principle that ignorance of the law is no defense applies whether the law be a statute or a duly promulgated and published regulation. In the context of these proposed 1960 amendments we decline to attribute to Congress the inaccurate view that that Act requires proof of knowledge of the law, as well as the facts, and that it intended to endorse that interpretation by retaining the word “knowingly.” We conclude that the meager legislative history of the 1960 amendments makes unwarranted the conclusion that Congress abandoned the' general rule and required knowledge of both the facts and the pertinent law before a criminal conviction could be sustained under this Act.
  So far as possession, say, of sulfuric acid is concerned the requirement of “mens rea” has been made a requirement of the Act as evidenced by the use of the word “knowingly.” A person thinking in good faith that he was shipping distilled water when in fact he was shipping some dangerous acid would not be covered. As stated in Morissette v. United States, 342 U. S. 246, 250:
  “The contention that an injury can amount to a crime only when inflicted by intention is no provincial or transient notion. It is as universal and persistent in mature systems of law as belief in freedom of the human will and a consequent ability and duty of the normal individual to choose between good and evil.”
  There is leeway for the exercise of congressional discretion in applying the reach of “mens rea.” United States v. Balint, 258 U. S. 250. United States v. Murdock, 290 U. S. 389, closely confined the word “willfully” in the income tax law to include a purpose to bring about the forbidden result:
  “He whose conduct is defined as criminal is one who ‘willfully’ fails to pay the tax, to make a return, to keep the required records, or to supply the needed information. Congress did not intend that a person, by reason of a bona fide misunderstanding as to his liability for the tax, as to his duty to make a return, or as to the adequacy of the records he maintained, should become a criminal by his mere failure to measure up to the prescribed standard of conduct. And the requirement that the omission in these instances, must be willful, to be criminal, is persuasive that the same element is essential to the offense of failing to supply information.” Id., at 396.
  In Balint the Court was dealing with drugs, in Freed with hand grenades, in this case with sulfuric and other dangerous acids. Pencils, dental floss, paper clips may also be regulated. But they may be the type of products which might raise substantial due process questions if Congress did not require, as in Murdock, “mens rea” as to each ingredient of the offense. But where, as here and as in Balint and Freedl, dangerous or deleterious devices or products or obnoxious waste materials are involved, the probability of regulation is so great that anyone who is aware that he is in possession of them or dealing with them must be presumed to be aware of the regulation.
  Reversed.
  The regulatory authority originally granted the Interstate Commerce Commission was transferred to the Department of Transportation by 80 Stat. 939, 49 U. S. C. § 1655 (e) (1964 ed., Supp. V).
  See H. R. Rep. No. 1975, 86th Cong., 2d Sess., 10-11.
  Id., at 2.
  Ibid.
  See the HEW Staff Memorandum, id., at 16-19.
  S. Rep. No. 901, 86th Cong., 1st Sess., 3.
  The Senate language might “well create an almost absolute liability for violation.” H. R. Rep. No. 1975, supra, at 2.
choices: Army and Air Force Exchange Service Atomic Energy Commission Secretary or administrative unit or personnel of the U.S. Air Force Department or Secretary of Agriculture Alien Property Custodian Secretary or administrative unit or personnel of the U.S. Army Board of Immigration Appeals Bureau of Indian Affairs Bureau of Prisons Bonneville Power Administration Benefits Review Board Civil Aeronautics Board Bureau of the Census Central Intelligence Agency Commodity Futures Trading Commission Department or Secretary of Commerce Comptroller of Currency Consumer Product Safety Commission Civil Rights Commission Civil Service Commission, U.S. Customs Service or Commissioner or Collector of Customs Defense Base Closure and REalignment Commission Drug Enforcement Agency Department or Secretary of Defense (and Department or Secretary of War) Department or Secretary of Energy Department or Secretary of the Interior Department of Justice or Attorney General Department or Secretary of State Department or Secretary of Transportation Department or Secretary of Education U.S. Employees' Compensation Commission, or Commissioner Equal Employment Opportunity Commission Environmental Protection Agency or Administrator Federal Aviation Agency or Administration Federal Bureau of Investigation or Director Federal Bureau of Prisons Farm Credit Administration Federal Communications Commission (including a predecessor, Federal Radio Commission) Federal Credit Union Administration Food and Drug Administration Federal Deposit Insurance Corporation Federal Energy Administration Federal Election Commission Federal Energy Regulatory Commission Federal Housing Administration Federal Home Loan Bank Board Federal Labor Relations Authority Federal Maritime Board Federal Maritime Commission Farmers Home Administration Federal Parole Board Federal Power Commission Federal Railroad Administration Federal Reserve Board of Governors Federal Reserve System Federal Savings and Loan Insurance Corporation Federal Trade Commission Federal Works Administration, or Administrator General Accounting Office Comptroller General General Services Administration Department or Secretary of Health, Education and Welfare Department or Secretary of Health and Human Services Department or Secretary of Housing and Urban Development Administrative agency established under an interstate compact (except for the MTC) Interstate Commerce Commission Indian Claims Commission Immigration and Naturalization Service, or Director of, or District Director of, or Immigration and Naturalization Enforcement Internal Revenue Service, Collector, Commissioner, or District Director of Information Security Oversight Office Department or Secretary of Labor Loyalty Review Board Legal Services Corporation Merit Systems Protection Board Multistate Tax Commission National Aeronautics and Space Administration Secretary or administrative unit or personnel of the U.S. Navy National Credit Union Administration National Endowment for the Arts National Enforcement Commission National Highway Traffic Safety Administration National Labor Relations Board, or regional office or officer National Mediation Board National Railroad Adjustment Board Nuclear Regulatory Commission National Security Agency Office of Economic Opportunity Office of Management and Budget Office of Price Administration, or Price Administrator Office of Personnel Management Occupational Safety and Health Administration Occupational Safety and Health Review Commission Office of Workers' Compensation Programs Patent Office, or Commissioner of, or Board of Appeals of Pay Board (established under the Economic Stabilization Act of 1970) Pension Benefit Guaranty Corporation U.S. Public Health Service Postal Rate Commission Provider Reimbursement Review Board Renegotiation Board Railroad Adjustment Board Railroad Retirement Board Subversive Activities Control Board Small Business Administration Securities and Exchange Commission Social Security Administration or Commissioner Selective Service System Department or Secretary of the Treasury Tennessee Valley Authority United States Forest Service United States Parole Commission Postal Service and Post Office, or Postmaster General, or Postmaster United States Sentencing Commission Veterans' Administration or Board of Veterans' Appeals War Production Board Wage Stabilization Board State Agency Unidentifiable Office of Thrift Supervision Department of Homeland Security Board of General Appraisers Board of Tax Appeals General Land Office or Commissioners NO Admin Action Processing Tax Board of Review