Illinois Statutes Chapter 40. Pensions § 5/6-106. Fireman

(a) was, is, or shall be employed by a city in its fire service as a fireman, fire paramedic, fire engineer, marine engineer, or fire pilot, and whose duty is to participate in the work of controlling and extinguishing fire at the location of any such fire, whether or not he is assigned to fire service other than the actual extinguishing of fire;

(b) is employed in the fire service of a city on the effective date, whose duty shall not be as hereinbefore stated, but who shall then be a contributor to, participant in, or beneficiary of any firemen's pension fund in operation by authority of law in such city on said date, unless he applies to the retirement board, within 90 days from the effective date, for exemption from the provisions of this Article. Any person who would have been entitled on July 1, 1931 to membership in this fund by reason of the definition of the word “fireman” contained in “An Act to provide for a firemen's pension fund and to create a board of trustees to administer said fund in cities having a population exceeding two hundred thousand (200,000) inhabitants”, filed July 14, 1917, as amended,  1 who has not filed with the board prior to July 1, 1941, a written application to be a member shall not be a fireman within the meaning of this Article; or

(c) made the election under Section 6-230.