Total recordable incident rate (TRIR) is a measure of recordable work-related injury and illness cases relative to hours worked, commonly expressed per 200,000 hours in US reporting. In US OSHA-style reporting, it is calculated as recordable injury and illness cases multiplied by 200,000 and divided by total employee hours worked for the same reporting population and period. The base represents 100 full-time equivalent employees working 2,000 hours each.
Recordability follows the applicable criteria and includes more than lost-time cases; it can include medical treatment beyond first aid, restricted work, and other qualifying outcomes. Near misses and first-aid-only cases are not automatically recordable. Other industry schemes may use a million-hour base. TRIR is a lagging frequency measure and does not directly quantify the severity or potential severity of every exposure.