What is required for the use of non-permissible blasting devices?

The correct response highlights that a permit is essential for the use, storage, or possession of non-permissible blasting devices at a mine. This requirement ensures that safety regulations are followed and that the potential hazards associated with non-permissible devices, which do not meet certain safety standards, are managed properly. Obtaining a permit typically involves demonstrating that appropriate safety measures are in place and that all operations using these devices comply with local and federal regulations. This process is critical in maintaining a safe working environment for all personnel involved in mining operations.

In the context of the other options, a letter from the local government may not encompass the necessary safety assessments and regulatory requirements for the use of such devices, and approval by the Director of Safety might be relevant but would typically fit under the permitting process rather than serve as a standalone requirement. Similarly, holding a certificate of competence pertains more directly to individual qualifications and training rather than the specific regulatory permissions needed for equipment usage.