TRIR

full_name: OSHA Total Recordable Incident Rate

formula: TRIR = (recordable cases × 200000) / total hours worked

multiplier_meaning: 200000 ≈ 100 employees × 40 hr/wk × 50 wk/yr — the OSHA standard exposure base

inputs:
recordable cases (OSHA 29 CFR 1904.7)
total hours worked

output_unit: cases per 100 full-time employees per year

jurisdiction: United States

authority: OSHA


LTIFR

full_name: Lost Time Injury Frequency Rate

formula: LTIFR = (LTI cases × 1000000) / total hours worked

multiplier_meaning: Per million hours worked — international ILO/HSE standard

inputs: lost time injuries (>1 day away from work)

output_unit: lost-time injuries per million hours

jurisdiction: International (ILO/UK/GCC/AU)

authority: ILO, UK HSE

source: ILO 16th ICLS Resolution III


DART

full_name: Days Away, Restricted, or Transferred Rate

formula: DART = (DART cases × 200000) / total hours worked

multiplier_meaning: Same OSHA 200000 base as TRIR; subset (cases with days away or job transfer/restriction)

inputs:
DART cases per OSHA 29 CFR 1904.7
total hours worked

output_unit: DART cases per 100 full-time employees per year


AFR

full_name: Accident Frequency Rate

formula: AFR = (accidents × 1000000) / total hours worked

multiplier_meaning: Per million hours; broader than OSHA recordable. Common UK HSE / GCC default

inputs: accidents (definition varies; often any reportable incident)

output_unit: accidents per million hours

jurisdiction: United Kingdom, GCC, generic

authority: UK HSE

source: HSE Methods Statement


Severity Rate

full_name: Severity Rate (days lost per million hours)

formula: Severity = (days lost × 1000000) / total hours worked

multiplier_meaning: Per million hours — a measure of how serious injuries are on average

inputs: total days lost (sum across all LTI cases)

output_unit: days lost per million hours

jurisdiction: International (ILO)

authority: ILO


TRIFR

full_name: Total Recordable Injury Frequency Rate

formula: TRIFR = (recordable injuries × 1000000) / total hours worked

multiplier_meaning: Same numerator as TRIR but per-million-hours basis (Australian / IOGP standard)

inputs:
recordable injuries
total hours worked

output_unit: recordable injuries per million hours

jurisdiction: Australia, NZ, IOGP global oil & gas

authority: Safe Work Australia, IOGP

source: Safe Work Australia WHS Code; IOGP Safety Performance Indicators


LTIR

full_name: Lost Time Incident Rate (OSHA basis)

formula: LTIR = (LTI cases × 200000) / total hours worked

multiplier_meaning: OSHA-basis equivalent of LTIFR — per 100 FTEs

inputs:
lost time injuries
total hours worked

output_unit: LTI per 100 FTE per year