In addition to the qualifications provided in the respective chapters of this code, a public member or a lay member of any board shall not be, nor shall he have been within the period of five years immediately preceding his appointment, any of the following:
(a) An employer, or an officer, director, or substantially full-time representative of an employer or group of employers, of any licentiate of such board, except that this shall not preclude the appointment of a person which maintains infrequent employer status with such licentiate, or maintains a client, patient, or customer relationship with any such licentiate which does not constitute more than 2 percent of the practice or business of the licentiate.
(b) A person maintaining a contractual relationship with a licentiate of such board, which would constitute more than 2 percent of the practice or business of any such licentiate, or an officer, director, or substantially full-time representative of such person or group of persons.
(c) An employee of any licentiate of such board, or a representative of such employee, except that this shall not preclude the appointment of a person who maintains an infrequent employee relationship or a person rendering professional or related services to a licentiate if such employment or service does not constitute more than 2 percent of the employment or practice of the member of the board.