18 U.S. Code § 343 - Presumptions

prev | next
For purposes of this chapter—
(1) an individual with a blood alcohol content of .10 percent or more shall be presumed to be under the influence of alcohol; and
(2) an individual shall be presumed to be under the influence of drugs if the quantity of the drug in the system of the individual would be sufficient to impair the perception, mental processes, or motor functions of the average individual.


(Added Pub. L. 99–570, title I, § 1971(a),Oct. 27, 1986, 100 Stat. 3207–59; amended Pub. L. 100–690, title VI, § 6473(c),Nov. 18, 1988, 102 Stat. 4379.)

1988—Par. (1). Pub. L. 100–690, § 6473(c)(1), substituted “.10 percent” for “.10” and struck out “conclusively” after “shall be”.
Par. (2). Pub. L. 100–690, § 6473(c)(2), struck out “conclusively” after “shall be”.

The table below lists the classification updates, since Jan. 3, 2012, for this section. Updates to a broader range of sections may be found at the update page for containing chapter, title, etc.

The most recent Classification Table update that we have noticed was Tuesday, August 13, 2013

An empty table indicates that we see no relevant changes listed in the classification tables. If you suspect that our system may be missing something, please double-check with the Office of the Law Revision Counsel.

18 USCDescription of ChangeSession YearPublic LawStatutes at Large


LII has no control over and does not endorse any external Internet site that contains links to or references LII.