Manager qualification in mines requires prescribed certificates, graded by mine type, output levels, and operating conditions. No mine may be opened, re-opened or worked unless it has a duly appointed manager with the prescribed qualifications for the relevant type of mine and level of output or material handled. Coal and metalliferous mines are governed by graded certificate requirements based on whether production or material handled exceeds specified thresholds, while mines having both open cast and underground workings require a First Class Manager's Certificate of Competency for coal or metal, as applicable. Oil mines require specified educational qualifications and experience in oil mine management, and the terms 'average output' and 'average material handled' are defined by reference to the preceding calendar year.