US CODE TITLE 50, Chapter 32, Section 1520 § 1520a. Restrictions on use of human subjects for testing of chemical or biological agents
Cornell University Law link to additional information on US code for experimentation on population
(a) Prohibited activities
The Secretary of Defense may not conduct (directly or by contract)—
(1) any test or experiment involving the use of a chemical agent or biological agent on a civilian population; or
(2) any other testing of a chemical agent or biological agent on human subjects.
Subject to subsections (c), (d), and (e) of this section, the prohibition in subsection (a) of this section does not apply to a test or experiment carried out for any of the following purposes:
(1) Any peaceful purpose that is related to a medical, therapeutic, pharmaceutical, agricultural, industrial, or research activity.
(2) Any purpose that is directly related to protection against toxic chemicals or biological weapons and agents.
(3) Any law enforcement purpose, including any purpose related to riot control.