Gov. Jay Inslee approved the revision, which was also supported by the Seattle lawyer who drafted the initiative that legalized recreational marijuana last year. The bill was first submitted in the Legislature just a week ago, and lawmakers in both chambers quickly moved it to the governor's desk.
"It was important to get this done in a timely fashion," Inslee said.
The problem centered around a portion of the initiative that was written to distinguish marijuana from industrial hemp, which is grown for its fiber. The measure defined marijuana as having more than 0.3 percent of a certain intoxicating compound, called delta-9 THC.
Scientists with the state crime lab say that often, even potent marijuana can have less than 0.3 percent of delta-9 THC. It's only when heated or burned that a different compound, THC acid, turns into delta-9 THC and the pot achieves its full potency.
Instead of accounting for just one intoxicating compound, the new measure accounts for both components, defining marijuana as having more than 0.3 percent of the two added together.
The change will help prosecutors to prove that plants or material meet the definition of marijuana when authorities uncover illicit grow operations or people carrying more than an ounce of marijuana - the amount adults are allowed to have under the law. The King County prosecutor's office had delayed filing charges in several cases until the law is fixed.
The technical fix was among more than two dozen bills Inslee signed Wednesday.
One of the bills removes the spousal exemption from third-degree rape - in which no physical force is used - and from taking indecent liberties. Until the 1970s, most states considered marriage to preclude any form of rape. Washington removed the marital exemption for first- and second-degree rape in 1983.
Another bill approved by Inslee seeks to crack down on the underage purchase of alcohol. It will require self-checkout machines at supermarkets to freeze transactions involving liquor sales until a worker verifies the buyer is at least 21 years old.