Or. Rev. Stat. § 663.110

      663.110 Employee organization, bargaining rights; union security agreements; payments to charitable institutions in lieu of union dues and other fees. Employees have the right to self-organization; to form, join or assist labor organizations; to bargain collectively through representatives of their own choosing; and to engage in other concerted activities for the purpose of collective bargaining or other mutual aid or protection. Employees also have the right to refrain from any or all of such activities except to the extent that this right may be affected by an agreement requiring membership in a labor organization as a condition of employment as authorized by ORS 663.125. However, agreements involving union security including an all-union agreement or agency agreement must safeguard the rights of nonassociation of employees, based on bona fide religious tenets or teachings of a church or religious body of which such employee is a member. Such employee must pay an amount of money equivalent to regular union dues and initiation fees and assessments, if any, to a nonreligious charity or to another charitable organization mutually agreed upon by the employee affected and the representative of the labor organization to which such employee would otherwise pay dues. The employee shall furnish written proof that this has been done. If the employee and representative of the labor organization do not reach agreement on the matter, the Employment Relations Board shall designate such organization. [1971 c.729 §5; 2003 c.14 §410]