The firemen's civil service commission in each municipality shall:
(1) Prescribe and enforce rules and regulations for carrying into effect the civil service provisions of this article. All rules and regulations so prescribed may, from time to time, be added to, amended or rescinded: Provided, That all rules and regulations shall be approved by the mayor and the governing body before they go into effect, but when so approved shall not be changed or rescinded except by the commission with the approval of the mayor and governing body: Provided, however, That if the mayor and governing body take no action on a proposed rule and regulation or a proposed change or rescission submitted to them within a period of twenty days from the date of submission, then the same shall become effective as though approved by the mayor and governing body.