When it comes to measuring safety performance in construction and infrastructure projects, two widely used systems are the TRIFR System and the OSHA Standard. While both aim to quantify safety outcomes, they differ significantly in how they calculate incident rates, how they interpret data, and how they scale across projects of different sizes.
Understanding these differences is essential for project managers, safety professionals, and compliance teams who rely on accurate metrics to assess risk, report performance, and meet regulatory or client requirements.
What is the TRIFR System?
TRIFR stands for Total Recordable Injury Frequency Rate. It is a metric commonly used in Australia, Canada, and other international regions to measure the number of recordable injuries per million hours worked.
- TRIFR Formula:
TRIFR = (LTI + MTI + RWI) × 1,000,000 ÷ Total Hours Worked
- LTI: Lost Time Injury
- MTI: Medical Treatment Injury
- RWI: Restricted Work Injury
This formula provides a high-level view of safety performance and is often used in corporate sustainability reports, client submissions, and internal benchmarking.
What is the OSHA Standard?
The OSHA Standard, used primarily in Canada and the United States, is based on the Total Recordable Incident Rate (TRIR) and uses a slightly different formula:
- OSHA TRIR Formula:
TRIR = (Number of Recordable Cases × 200,000) ÷ Total Hours Worked
- 200,000 represents the number of hours 100 full-time employees work in a year (40 hours/week × 50 weeks)
- Recordable cases include fatalities, LTIs, RWIs, and MTIs
- First aid cases are excluded
This standardised multiplier allows companies of different sizes to compare safety performance on a consistent scale. However, it can disproportionately affect smaller teams, where a single incident may significantly inflate the rate.
Key Differences in Calculation
| Feature | TRIFR System | OSHA Standard |
| Multiplier | 1,000,000 | 200,000 |
| Scope | LTI + MTI + RWI | OSHA-defined recordable cases |
| Use Case | International projects, client-specific reporting | U.S.-based compliance and benchmarking |
| Sensitivity | More granular for large-scale projects | Can skew results for small teams |
| Output Format | Often used in dashboards and reports | Used in compliance audits and regulatory filings |
Real-World Example
Let’s say a project logged 3 recordable incidents over 500,000 hours worked:
- TRIFR: (3 × 1,000,000) ÷ 500,000 = 6.0
- OSHA TRIR: (3 × 200,000) ÷ 500,000 = 1.2
This difference can impact how safety performance is interpreted, especially when comparing across projects or reporting to clients.
Glaass Update: Dual Safety Rate Display
Recognising the need for flexibility, Glaass recently released an update that allows users to toggle between the TRIFR System and the OSHA Standard when viewing safety analytics.
- Safety rates are now calculated using data from the relevant templates
- This update supports better decision-making and ensures compliance with both international and Canadian/U.S. standards
The feature is currently live in our project in Toronto, PTUS, with broader rollout expected following successful testing in Glaass’ beta environment.
Why This Matters
- For global teams: Enables consistent reporting across jurisdictions.
- For compliance: Meets both client and regulatory expectations.
- For analytics: Improves accuracy and transparency in safety performance tracking.
Whether you’re working on a metro tunnel in Melbourne or a rail corridor in Toronto, having access to both systems ensures your safety data is meaningful, compliant, and actionable.
