(a) Any department or agency of this State or any political subdivision thereof is hereby authorized to participate in a program of interchange of employees with departments and agencies of the federal government, or this or any other state or any of their political subdivisions as a sending or receiving agency, or both.

(b) The period of individual assignment or detail under an interchange program shall not exceed two years; provided, however, the sending agency with the consent of the receiving agency may extend the period of assignment for not more than two additional years. Elected public officials of this State or any of its political subdivisions shall not be assigned from a sending agency nor detailed to a receiving agency.

(c) No employee of this State or any of its political subdivisions shall be required to participate in an interchange program without his consent.