The Senate approved a measure Saturday, that prosecutors and crime lab scientists say is needed because of concerns that a provision in Washington's new legal marijuana law jeopardizes their ability to go after any pot crimes at all.

The measure that passed unanimously defines marijuana as part of the cannabis plant containing more than 0.3 percent of delta-9 THC and THC acid. Supporters said the change was a technical fix needed to help police and prosecutors distinguish marijuana from industrial hemp, which is grown for its fiber. The House approved the bill on Friday and it now heads to the governor.