Hazardous Mataterial - Recognizing and Identifying the Hazards No. 1 Questions taken from Jones & Bartlett Fundamentals of Fire Fighter Skills (3rd Edition) Progress Indicator: Question 3 of 20 3.  How often do methane tests in any structure, enclosure, or other facility have to be made? Choices: weekly every shift at least once every 24 hours once during each operating shift none of the above