Wash. Rev. Code § 49.12.350
The legislature finds that employers often distinguish between biological parents, and adoptive parents and stepparents in their employee leave policies. Many employers who grant leave to their employees to care for a newborn child either have no policy or establish a more restrictive policy regarding whether an adoptive parent or stepparent can take similar leave. The legislature further finds that many employers establish different leave policies for men and women regarding the care of a newborn or newly placed child. The legislature recognizes that the bonding that occurs between a parent and child is important to the nurturing of that child, regardless of whether the parent is the child's biological parent and regardless of the gender of the parent. For these reasons, the legislature declares that it is the public policy of this state to require that employers who grant leave to their employees to care for a newborn child make the same leave available upon the same terms for adoptive parents and stepparents, men and women.
RCW 49.12.350
Effective date-1989 1st ex.s. c 11: "This act shall take effect September 1, 1989." [ 1989 1st ex.s. c 11 s 27.]