(

a) Sections 31662.4, 31662.6, 31662.8, and shall not apply to a person who is an active safety member described in

Section 31469.3 or 31470.4 if a physician employed or approved by the county certifies that the safety member is capable of performing his or her assigned duties pursuant to standards set forth by the member’s employer. (

b) This

section shall also apply to a member who reinstates from retirement pursuant to

Section 31680.8. (

c) A county that adopts this

section shall provide a safety member who is on a disability leave of absence the opportunity to receive the physician certification described in subdivision (

a) upon return from his or her leave, and that member shall not be subject to mandatory retirement pursuant to

Section 31662.4, 31662.6, or 31662.8 prior to receiving that opportunity. (

d) This

section applies only to a county of the first class, as defined by

Section 28020, as amended by

Chapter of the Statutes of 1971, and

Section 28022, as amended by

Chapter of the Statutes of 1961. (

e) This

section shall not be operative in any county until the board of supervisors shall, by resolution adopted by a majority vote, make this

section and

Section 31680.8 applicable in the county. The resolution of the board of supervisors may designate a date, which may be prior to the date of the resolution or the effective date of this section, upon which the resolution and this

section shall be operative in the county, and may further provide that a member, described in

Section 31470.4, who retired pursuant to

Section 31662.4 or 31662.6, prior to April 1, 2007, is not eligible to reinstate from retirement pursuant to

Section 31680.8.