Union security; dues deduction.

Any labor organization which has been certified as the exclusive representative shall, upon request, have its dues and uniform assessments deducted and collected by the employer from the salaries of those employees who authorize the deduction of said dues. Such authorization, costs, and termination shall be proper subjects of collective bargaining. Service fees may be deducted from an employee’s salary by the employer if such a provision is contained in the bargaining agreement.