Total Recordable Incident Rate

The Total Recordable Incident Rate is a US measure of occupational safety and health, useful for comparing working conditions in workplaces and industries. It is calculated by combining the actual number of safety incidents and total work hours of all employees with a standard employee group (100 employees working 40 hours a week for 50 weeks a year).[1][2][3]

There are three parts to the TRIR formula and understanding them can help reduce your company’s TRIR.[4]

1.      Total number of OSHA-recordable incidents (or the number of injuries and illnesses to a company's employees.)

2.      The number 200,000.

3.      Total hours worked by everybody in the company.

Item 1: Total number of OSHA-Recordable Incidents

The first item is the total number of OSHA-recordable incidents.  This number can be found on the company’s OSHA 300 forms. The lower this number is, the lower the TRIR will be.  In the next section, I will explain how to evaluate your company’s OSHA forms to ensure that only OSHA-recordable incidents are recorded on your OSHA forms and not First Aid cases.  A First Aid injury is not required by OSHA to be recorded on your OSHA forms.

Item 2: The Number 200,000.

The second item is the number 200,000.  This number is included for two reasons.

First, it makes the TRIR easier to read.  Without the number 200,000 in the formula, a typical TRIR for a company with 1 injury would read 0.000005 (5 zeros after the decimal point.)  This is a difficult number to read.  And this number 0.00005 (4 zeros after the decimal point) looks very much like the first number, but it is actually 10 times larger.

With the number 200,000 included in the formula, the first TRIR becomes "1" and the second TRIR becomes "10".  These numbers are much easier to read and understand.

Any large number could have been selected to make the TRIR easier to read, but the second reason the number 200,000 was chosen is that it represents the total number of hours that 100 full-time employees would work in a single year.

·        1 full-time employee will work 2,000 hours in a single year (40 hours per week x 50 weeks per year.)

·        100 full-time employees will work 200,000 hours in a single year.

Why is this important? The number 200,000 makes the TRIR represent the percentage of employees that were injured in a business.

·        A TRIR of 3.5, means that 3.5% of your workforce suffered an OSHA-recordable injury.

·        A TRIR of 12.3 means that 12.3% of your employees suffered an OSHA-recordable injury.

Item 3: Total Hours Worked by Everybody in the Company

The last item is in the denominator, or bottom, of the formula and it is the total number of hours worked by all employees and owners.  This number needs to be as large as possible.  As your total number of hours worked goes up, your TRIR goes down.  I'll show you the common mistakes that most businesses make when computing their total hours worked.