Wash. Rev. Code § 46.61.503
(1) Notwithstanding any other provision of this title, a person is guilty of driving or being in physical control of a motor vehicle after consuming alcohol or cannabis if the person operates or is in physical control of a motor vehicle within this state and the person:
(b) Has, within two hours after operating or being in physical control of the motor vehicle, either:
(2) It is an affirmative defense to a violation of subsection (1) of this section, which the defendant must prove by a preponderance of the evidence, that the defendant consumed a sufficient quantity of alcohol or cannabis after the time of driving or being in physical control and before the administration of an analysis of the person's breath or blood to cause the defendant's alcohol or THC concentration to be in violation of subsection (1) of this section within two hours after driving or being in physical control. The court shall not admit evidence of this defense unless the defendant notifies the prosecution prior to the earlier of:
[ 2022 c 16 s 41; 2015 2nd sp.s. c 3 s 14; 2013 c 3 s 34 (Initiative Measure No. 502, approved November 6, 2012). Prior: 1998 c 213 s 4; 1998 c 207 s 5; 1998 c 41 s 8; 1995 c 332 s 2; 1994 c 275 s 10. Formerly RCW 46.20.309.]
Intent—Finding—2022 c 16: See note following RCW 69.50.101.
Finding—Intent—2015 2nd sp.s. c 3: See note following RCW 10.21.055.
Intent—2013 c 3 (Initiative Measure No. 502): See note following RCW 69.50.101.
Effective date—1998 c 213: See note following RCW 46.20.308.
Effective date—1998 c 207: See note following RCW 46.61.5055.
Intent—Construction—Effective date—1998 c 41: See notes following RCW 46.20.265.
Severability—Effective dates—1995 c 332: See notes following RCW 46.20.308.
Short title—Effective date—1994 c 275: See notes following RCW 46.04.015.