What it means
TRIR counts the recordable injuries and illnesses a company had in a period and scales them to the hours its people worked. The scale is 200,000 hours, the base OSHA uses.
The formula: TRIR = (number of recordable incidents x 200,000) / total hours worked by all employees in the same period. Use the same period for both numbers, usually a calendar year.
What counts as recordable comes from OSHA 29 CFR 1904. Check the current OSHA recordkeeping rules before you count a case. Hours worked should be real hours, not scheduled hours.
Why it matters
A small crew and a large one can't be compared by raw injury counts. TRIR puts them on one scale. Customers, prime contractors and insurers often ask for it before they let a contractor on site. It's a lagging number, though. It tells you what already happened.
What it looks like on a site
- The safety lead pulls the year's recordable cases from the 300 log and the total hours from payroll.
- A prime contractor asks for your TRIR on a prequalification form before the first day on site.
- The lead reports it monthly and year to date, and reads it next to near misses and observations.
- Hours from subcontractors and temps are counted the way your recordkeeping procedure says to count them.
- One bad case on a small crew moves the number a lot, so the lead reads the trend, not one month.
This is general information, not legal advice. Check the current rule and your own procedures. Back to the glossary