What does the term 'approved' signify in mining regulations?

The term 'approved' in mining regulations signifies that devices or practices have been authorized by a recognized authority, such as the Chief or Director. This means that these practices or devices have undergone evaluation and have been deemed acceptable according to specific safety and operational standards set forth by regulatory bodies. The approval process ensures that any method or device used in mining adheres to legal and safety requirements, thereby protecting the health and safety of workers and the environment.

In contrast, the other options do not capture the regulatory and authoritative aspect of the term. While materials that meet state standards may be compliant, they are not necessarily endorsed through a formal approval process. Methods widely accepted by miners could reflect common practices, but without the sanction of a regulatory authority, they lack the formal validation implied by the term 'approved.' Lastly, old methods with historical significance may hold value for educational or contextual reasons but do not indicate current compliance with modern standards or practices as required by regulatory authorities.