An advance made under RCW 42.24.120 through 42.24.160 shall be considered as having been made to such officer or employee to be expended by him or her as an agent of the municipal corporation or political subdivision for the municipal corporation's or political subdivision's purposes only, and specifically to defray necessary costs while performing his or her official duties.

No such advance shall be considered as a personal loan to such officer or employee and any expenditure thereof, other than for official business purposes, shall be considered a misappropriation of public funds.