Safety incident rate (TRIR)

What it is

US employers covered by OSHA recordkeeping log work-related injuries and illnesses on the OSHA 300 log (OSHA recordkeeping). The total recordable incident rate (TRIR) turns the count into a rate per 100 full-time equivalent workers, using a base of 200,000 hours (BLS).

The DART rate uses only cases with days away from work, restricted duty, or job transfer.

Why operators track it

• Prequalification. Owners and GCs commonly ask for safety rates when qualifying contractors and subs.
• People. The first reason to track it.
• Cost. Injuries affect insurance cost and project schedules.
• Trends by job and trade. Shows where to focus training.

How it is calculated

TRIR = recordable cases × 200,000 ÷ total hours worked

• 200,000 = 100 full-time workers × 40 hours × 50 weeks (BLS).
• DART rate = DART cases × 200,000 ÷ hours worked.
• Use the same period for cases and hours, usually a calendar year or rolling 12 months.

Worked example

From January through October the company had 3 recordable cases and 412,000 hours worked. TRIR is 3 × 200,000 ÷ 412,000 = 1.46. One case involved days away, so the DART rate is 0.49.

How to read it

• Small contractors swing. One case moves the rate a lot when hours are low. Show counts with the rate.
• Use rolling 12 months for a stable trend.
• Leading indicators help. Near misses and inspections show risk before injuries.
• BLS publishes industry rates by NAICS code (BLS). If you compare, use the published figure for the exact industry and year, with a link.

Definitional choices and common pitfalls

• Who is included. Employees only, or include subcontractor hours on your sites. OSHA rates are per employer; site rates are a separate view.
• Hours source. Hours actually worked, not hours paid. Exclude vacation and holiday.
• Period. Calendar year matches the OSHA 300A summary; rolling 12 months is better for trend.
• Recordability. Recordability follows OSHA rules. The software should take the classification as entered, not decide it.

How different roles use it

Questions it answers

• What is our TRIR and DART rate this year?
• Which jobs or trades had incidents?
• Is the trend improving?
• What rate do we report on prequalification forms?

How to present it in a report

• KPIs for TRIR and DART, with case counts and hours beside them.
• Rolling 12-month trend line.
• Incidents by job, trade, and type.
• Leading indicators alongside, if tracked.

Data you need

Fields

What the raw data looks like

Example data A few rows as they might come out of the source system.

Where this data usually lives

• Safety tools or spreadsheets hold the incident log and OSHA 300 data.
• Payroll and time tracking hold hours and labor cost by job and cost code, sometimes from a field time app.

The same field can live in more than one system. Agree with the customer which one is the source of truth.

Common data gaps and traps

• Incidents in a safety tool, hours in payroll. Two systems to join by month and job.
• Hours paid vs worked. Payroll may only have paid hours.
• Sub hours missing. Sub incidents may be logged without their hours.
• Recordable flag missing. First aid and recordable may not be separated.

Related metrics

• Subcontractor compliance: safety documents for subs.
• Labor productivity: the same hours data.
• Equipment utilization: equipment on the same sites.

FAQ

What is the 200,000 in the TRIR formula?

The hours 100 full-time employees work in a year at 40 hours a week for 50 weeks (BLS).

What is a DART rate?

The rate of cases with days away from work, restricted duty, or job transfer, on the same 200,000-hour base.

What is a good TRIR?

Compare with the BLS published rate for your industry code and year, cited with a link. We do not repeat a figure here.

trir = recordable_cases * 200000 / hours_worked
dart = dart_cases * 200000 / hours_worked
-- same period for numerator and denominator, e.g. rolling 12 months

SELECT COUNT(*) FILTER (WHERE recordable) * 200000.0 / h.hours AS trir,
       COUNT(*) FILTER (WHERE case_type IN ('days_away','restricted_transfer')) * 200000.0 / h.hours AS dart
FROM incidents i, (SELECT SUM(hours) hours FROM hours_worked WHERE work_date > :as_of - 365) h
WHERE i.occurred_at > :as_of - 365 AND i.employer_type = 'own' GROUP BY h.hours;

metric: construction.safety_incident_rate
grain: company per rolling 12 months; optional by job
inputs:
  - recordable flag
  - case type
  - hours worked
logic:
  - trir = recordable * 200000 / hours
  - dart = dart cases * 200000 / hours
edge_cases:
  - hours = 0: null
  - own vs sub: separate rates
  - recordable status changed later: use latest classification

Version 1.0 · Last reviewed 2026-10-20 · Machine-readable definition