What record must the VO ensure for general body concentrations of atmospheric contaminants and gases, and how long must the record be kept?

• A. The results of monitoring the ventilation system for the listed contaminants; kept for 7 years after it is made.
• B. Daily air temperature readings; kept for 5 years.
• C. Employee shift rosters; kept for 2 years.
• D. Electrical maintenance logs; kept for 10 years.

Answer: (A)

The essential idea is that there must be a formal record of the results from monitoring the ventilation system for the general body concentrations of atmospheric contaminants and gases, and that this ambient air monitoring record must be kept for seven years after it is created. This record is the primary evidence that workers are not being exposed to harmful levels in the general mine atmosphere, and it supports compliance with exposure standards, regulatory audits, and any health investigations that follow over time. Keeping it for seven years ensures there’s a long enough window to review trends, verify corrective actions if concentrations shift, and respond to any future regulatory or health concerns. Records like daily air temperature, employee rosters, or electrical maintenance logs aren’t the ambient contaminant monitoring records required here, so they don’t satisfy this specific obligation.