Which term is defined as the number of total fatal and non-fatal lost-time accidents per million manhours worked?

• A. Accident Frequency Rate
• B. Accident Severity Rate
• C. Lost-time Rate
• D. Injury Rate

Answer: (A)

This concept measures how often safety incidents occur relative to hours worked. Accident Frequency Rate is defined as the number of fatal and non-fatal lost-time accidents per million man-hours worked. It captures how frequently incidents happen, regardless of how severe the injuries are, which is why it’s the best fit for this description.

For example, if a site records 3 fatal or non-fatal lost-time accidents over 2,000,000 man-hours, the Accident Frequency Rate would be (3 × 1,000,000) / 2,000,000 = 1.5 per million hours.

The other terms focus on different aspects: Accident Severity Rate looks at the seriousness of injuries (usually days lost or severity per incident or per hours worked); Lost-time Rate emphasizes injuries that result in time off work (often per million hours) and may not reflect fatal incidents separately; Injury Rate is a broader label that can refer to injuries per hours worked but without specifying lost-time or fatal/non-fatal distinctions.