What Does Total Recordable Incident Rate (TRIR) Mean?
The Total Recordable Incident Rate (TRIR) is a metric used to assess a company's safety performance over the course of a year. The lower the TRIR, the better the company's safety performance is considered to be.
TRIR is calculated by tallying up the number of recordable incidents (work-related injuries and illnesses) per 100 full-time workers over the course of a year. This tracks safety issues incidents across a wide range of severity, including everything from minor injuries that require treatment beyond first aid to fatal accidents.
Safeopedia Explains Total Recordable Incident Rate (TRIR)
To calculate your company's Total Recordable Incident Rate, multiply the number of recordable incidents by 200,000. Then divide by the total number of employee hours worked in the year.
(Recordable incidents X 200,000) / Total number of hours worked
The 200,000 figure represents the total hours 100 employees would work over the course of 50 weeks, assuming a 40-hour work week.
To ensure accuracy, it's important to exclude vacation time and employee leave from the total number of hours worked. Hours worked by contractors should also be included. While they may not strictly be employed by the company, any incident involving them will count as one of the company's recordable incidents.
Critiques and Limitations of TRIR
Calculating a company's TRIR is a rough and ready way to get a sense of its safety performance and whether it is improving year over year. However, it's a metric with inherent limitations and many safety professionals have brought its utility into question.
The following are some of the more prominent critiques of TRIR.
TRIR Is Only Useful at the Macro Scale
While TRIR is a useful tool for analyzing large-scale safety data across industries, some argue that it is far less relevant when applied to individual companies. Because it does not always accurately reflect small-scale safety improvements, a company's TRIR may remain high even after it has implemented better safety measures, giving the mistaken impression that those safety initiatives aren't working.
TRIR Can Be Skewed by the Ratio of Incident to Hours Worked
Since the TRIR tracks the relation between incidents and total hours worked, a company with a higher number of incidents could have a lower TRIR score if they have clocked in a large number of worker hours. This can make such a company seem safer on paper than a company with fewer incidents and fewer worker hours.
These discrepancies raise questions about whether the TRIR is too easily skewed to be a meaningful metric.
TRIR Has Little to No Predictive Power
Research has found that a company's current TRIR score is not predictive of its future TRIR scores, unless you can base the calculation on at least nine years' worth of data. This means that a company's TRIR score, even over the course of a few years, does not provide any indication of whether its safety performance is trending in a positive direction.
Without this kind of predictive power, TRIR has very limited uses.
TRIR Does Not Correlate with Fatality Rates
Research shows that fatality rates do not keep pace with changes to TRIR. Since there is no statistical relationship between TRIR and fatalities, taking steps to reduce a company's TRIR will not necessarily reduce the risk of severe or fatal injury. This suggests that improving a company's TRIR does not have a significant impact on the actual safety of its operations.
Moving Beyond TRIR
Given the limitations of TRIR as a safety metric, many safety professionals recommend minimizing its importance or doing away with it entirely. Many advocate for tracking leading indicators and focusing on safety culture rather than relying on TRIR to measure performance.