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SME Explanation

Mine Safety and Health Administration

Severity Measure is the number of lost workdays per 200,000 employee-hours. The Severity Measure formula is number of lost workdays x 200,000 divided by the number of employee hours. Office worker and contractor hours and lost workdays are excluded. Lost workdays consist of days away from work and days of restricted work activity, or statutory days charged as prescribed from a table of standard charges, e.g., 6,000 days for a fatality or permanent total disability. Only statutory days are used in the fatality and disability cases.

The Severity Measure for each mine is computed for all lost-workday accidents that occurred during the most recent 12 months for which injury and employee hour data (as reported under 30 CFR Part 50) is available. Accidents during this time period without return to work information will be calculated as lost or restricted work days from the time of the injury to the report run date. This calculation assumes a five day work week and excludes Federal holidays. Each mine's severity measure is compared to the applicable severity measure for the six mine types and classifications over the most recent five years for which closed out data reported under 30 CFR Part 50 is available. The five-year severity measure, rather than a one-year severity measure, is used to compensate for annual fluctuations in the severity measures, and to allow mine operators to have a fixed measure against which to monitor their most recent performance.

There are six mine types and classifications used to calculate the Severity Measure for pattern of violation screenings: underground coal mines; surface coal mines; surface coal facilities; underground metal and nonmetal mines; surface metal and nonmetal mines; and surface metal and nonmetal facilities.