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Safety guides and audits to make your job as a safety professional easier

Incident Rates

How does your company compare?

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How to calculate incident rates.

It's useful to be able to evaluate your company's injury-and-illness experience over time to compare it's experience with that of your industry as a whole. To do that you need to compute your incident rate. Incident rates can, to a certain degree, help you identify problems in your workplace or progress made toward preventing work-related injuries and illnesses.

Are incident rates really important?

Incidence rates can be useful as a measure in evaluating your organization's safety management system. Incidence rates measure "what's already happened." They primarily measure how many fatalities, injuries, and accidents have occurred over time. Do not rely solely on incident rates: here's why.

Trailing indicators measure the "effect"

Incidence rates are "trailing indicators." They record and summarize historical data. Incidence rates do not measure the actual "causes" of injury and illness incidents: they measure the "effect," not the cause, of the incident. Relying solely on incident rates to improve your safety management system is not effective. It's like driving down the road and looking in the rear-view mirror to stay in your lane. Other examples of trailing indicators are: workers compensation rates, equipment failure rates, unsafe behavior rates. However the most common trailing indicator remains the incident rate.

Leading indicators measure the "cause"

Actually, it's more important to emphasize the measurement of "leading indicators." These are the thoughts, decisions, behaviors, and activities that have the most direct influence on safety management system design, development and deployment. Incidence rates for fatalities, injuries, and accidents can be used to determine if they are leading indicators.

As long as you measure both leading and trailing indicators, you're on the right track.

Two Common Statistical Measurements

There are two basic ways to calculate required incident rates for annual OSHA reporting, the OSHA SHARP program, and the OSHA VPP program:

  1. the Days Away, Restricted, or Job Transferred (DART) Rate which is used for OSHA recordkeeping and reporting, and to qualify for the OSHA SHARP.
  2. the Total Case Incident Rate (TCIR) which is required to qualify for the VPP, and

Days Away, Restricted, or Transferred (DART) Rate

Since the DART Rate is the most common incident rate used in the safety profession, it's important to know how to calculate it. You can compute the incident rate for recordable cases involving days away from work, days of restricted work activity, or job transfer using the following formula:

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How to Calculate The DART Rate

The formula above is quite simple and easy to use. Just follow these steps:

  1. Determine the DART (N):Count the number of line entries on your OSHA Form 300 that received a check mark in columns (H) and (I), or refer to the entry in columns (H) and (I) on the OSHA Form 300A.
  2. Calculate total workhours: The number of hours all employees actually worked during the year. Use the OSHA Form 300A and optional worksheet to calculate this number. If actual hours worked are not available for employees paid on commission, salary, by the mile, etc., hours worked may be estimated on the basis of scheduled hours or 8 hours per workday.
  3. The 200,000 figure in the formula represents the number of hours 100 employees working 40 hours per week, 50 weeks per year would work and provides the standard base for calculating incident rates.

Total Case Incident Rate (TCIR)

The Total Case Incident Rate (TCIR) is based on the number of recordable injuries and illnesses occurring among a given number of full-time workers (usually 100 full-time workers) over a given period of time (usually one year). In Europe the incident rate may be based on 500 full-time workers. It is a required calculation for companies applying for VPP status.

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How to Calculate the TCIR

As you can see, the calculation for the TCIR is similar to the DART. You can calculate the TCIR using the following steps:

  1. Determine the number of injuries and illnesses (N): Count the number of line entries on your OSHA Form 300 or use the OSHA Form 300A and sum the entries for columns (G), (H), (I), and (J).
  2. Determine total workhours (EH): The number of hours all employees actually worked during the year. Use the OSHA Form 300A and optional worksheet to calculate this number. If actual hours worked are not available for employees paid on commission, salary, by the mile, etc., hours worked may be estimated on the basis of scheduled hours or 8 hours per workday.
  3. The 200,000 figure in the formula represents the number of hours 100 employees working 40 hours per week, 50 weeks per year would work and provides the standard base for calculating incident rates.

Let's see how this works

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Form for calculating the DART and TCIR. Click to Enlarge

Here's an example. If you have 50 employees who work a total of 100,000 hours during the year and have experienced 10 recordable injuries, the DART rate would be (10 ÷ 100,000) x 200,000 = 20. So, in this example, the DART rate indicates there are 20 days away, restricted, or transferred injuries per 100 employees. The number of employees doesn't matter. The total number of injuries and the total number of hours the employees work during the year are the two important figures entered into the formula.

You can use the same formula to calculate incident rates for other variables such as cases involving restricted work activity (Column (I) on OSHA Form 300A), cases involving skin disorders (Column (M-2) on OSHA Form 300A), etc. Just substitute the appropriate total for these cases, from OSHA Form 300A, into the formula in place of the total number of injuries and illnesses.

Instructions

Before beginning this quiz, we highly recommend you review the module material. This quiz is designed to allow you to self-check your comprehension of the module content, but only focuses on key concepts and ideas.

Read each question carefully. Select the best answer, even if more than one answer seems possible. When done, click on the "Get Quiz Answers" button. If you do not answer all the questions, you will receive an error message.

Good luck!

1. Which of the following is NOT true concerning injury and illness rates?

2. Which of the following best defines an "incident rate"?

3. To find out the number of injuries and illnesses that involved days away from work and days of restricted work (DART) using the OSHA 300 Log, you would refer to the entries in columns _____.

4. Which formula below is used to determine the DART rate?

5. What is the DART Rate for a company that had 10 injuries and 80 employees who worked a total of 150,000 hours during the year?


Have a great day!

Important! You will receive an "error" message unless all questions are answered.