How often must SCSRs be checked when stored?

Self-Contained Self-Rescuers (SCSRs) are critical safety devices used in coal mines for providing a breathable atmosphere in the event of an emergency, such as a fire or a lack of oxygen. Regular checks of SCSRs are essential to ensure their functionality and readiness for use when necessary.

The correct frequency for checking SCSRs is every 90 days. This timeframe strikes a balance between ensuring that these safety devices are adequately maintained and readily available while also allowing for a manageable inspection schedule for mine operators. Regular inspections help identify any signs of wear, damage, or issues that may affect the performance of the SCSR, thereby ensuring the safety of miners in emergency situations.

For the other options, more frequent checks would arguably increase operational loads and may be unnecessary if protocols are followed correctly, while less frequent checks would increase the risk of malfunction due to potential deterioration or environmental factors affecting the SCSR when not in service. Hence, checking them every 90 days is a well-established practice that helps maintain safety without imposing excessive demands on resources.