The PEIRAF shall be available to all public employees in the State of Alabama who are members of the Teachers’ Retirement System, the Employees’ Retirement System or the Judicial Retirement Fund. In addition, any employee of an employer eligible to participate in the Employees’ Retirement System pursuant to the provisions of Section 36-27-6, or any public official or employee of the State of Alabama or any political subdivision thereof, shall be eligible to participate under the provisions of this chapter. Participation in this fund shall be on a strictly voluntary basis under such rules and regulations as shall be adopted by the board of control and in accordance with the provisions contained in the Internal Revenue Code as it relates to individual retirement accounts for public employees. Any person who shall become ineligible for participation in the PEIRAF due to the termination of his employment with an eligible employer may leave his contributions on account with the PEIRAF; however, no further contributions may be accepted on his account unless such person shall become reemployed by an eligible employer.