18 U.S.C. § 229 : US Code - Section 229: Prohibited activities

      (a) Unlawful Conduct. - Except as provided in subsection (b), it
    shall be unlawful for any person knowingly - 
        (1) to develop, produce, otherwise acquire, transfer directly
      or indirectly, receive, stockpile, retain, own, possess, or use,
      or threaten to use, any chemical weapon; or
        (2) to assist or induce, in any way, any person to violate
      paragraph (1), or to attempt or conspire to violate paragraph
      (1).

      (b) Exempted Agencies and Persons. - 
        (1) In general. - Subsection (a) does not apply to the
      retention, ownership, possession, transfer, or receipt of a
      chemical weapon by a department, agency, or other entity of the
      United States, or by a person described in paragraph (2), pending
      destruction of the weapon.
        (2) Exempted persons. - A person referred to in paragraph (1)
      is - 
          (A) any person, including a member of the Armed Forces of the
        United States, who is authorized by law or by an appropriate
        officer of the United States to retain, own, possess, transfer,
        or receive the chemical weapon; or
          (B) in an emergency situation, any otherwise nonculpable
        person if the person is attempting to destroy or seize the
        weapon.

      (c) Jurisdiction. - Conduct prohibited by subsection (a) is
    within the jurisdiction of the United States if the prohibited
    conduct - 
        (1) takes place in the United States;
        (2) takes place outside of the United States and is committed
      by a national of the United States;
        (3) is committed against a national of the United States while
      the national is outside the United States; or
        (4) is committed against any property that is owned, leased, or
      used by the United States or by any department or agency of the
      United States, whether the property is within or outside the
      United States.