Cal. Gov. Code § 20434.5
"Local firefighter" also means any officer or employee of a fire department of a contracting agency, except one whose principal duties are those of a telephone operator, clerk, stenographer, machinist, mechanic, or otherwise, and whose functions do not clearly fall within the scope of hazardous materials services, even though that employee is subject to occasional call, or is occasionally called upon, to perform duties within the scope of hazardous materials services, but not excepting persons employed and qualifying as firefighters or equal or higher rank, irrespective of the duties to which they are assigned.
This section shall not apply to the employees of any contracting agency nor to any contracting agency unless and until the contracting agency elects to be subject to this section by amendment to its contract with the board, made pursuant to Section 20474 or by express provision in its contract with the board.
Ca. Gov. Code § 20434.5