COSS - Certified Occupational Safety Specialist Incident Rate Calculations Questions and Answers — Questions and Answers
Question 1: A manufacturing company with 150 full-time employees, each working 2,000 hours per year, experienced 7 OSHA recordable incidents. What is the company's Total Recordable Incident Rate (TRIR)?
- 3.5
- 4.67 (Correct answer)
- 2.33
- 7.0
Correct answer: 4.67
The TRIR is calculated using the formula: (Number of Recordable Incidents × 200,000) / Total Hours Worked. First, calculate total hours: 150 employees * 2,000 hours/employee = 300,000 hours. Then, apply the formula: (7 * 200,000) / 300,000 = 1,400,000 / 300,000 = 4.67.
Question 2: When calculating incident rates like TRIR or DART, what does the 200,000 figure in the formula represent?
- The maximum number of hours any single employee is legally allowed to work per year.
- The total number of hours worked by an average small business with 50 employees.
- The equivalent hours worked by 100 full-time employees in a calendar year. (Correct answer)
- The national average number of work-related injuries and illnesses reported annually.
Correct answer: The equivalent hours worked by 100 full-time employees in a calendar year.
The 200,000 figure is a standard base used by OSHA to normalize the data. It represents the hours that 100 employees would work in a year, assuming each works 40 hours per week for 50 weeks (100 employees x 40 hours/week x 50 weeks/year = 200,000 hours). This allows for comparison between companies of different sizes.
Question 3: A construction company logged 525,000 hours worked in a year. During this period, they had 3 incidents that resulted in days away from work and 2 incidents that required job restrictions. What is the company's DART rate?
- 1.90 (Correct answer)
- 1.14
- 0.76
- 2.66
Correct answer: 1.90
The DART (Days Away, Restricted, or Transferred) rate includes only incidents that result in those outcomes. The formula is: (Number of DART Incidents × 200,000) / Total Hours Worked. Here, the number of DART incidents is 3 + 2 = 5. So, (5 * 200,000) / 525,000 = 1,000,000 / 525,000 = 1.90.
Question 4: Which of the following incidents would be included when calculating a company's DART (Days Away, Restricted, or Transferred) rate?
- An employee receives stitches at a clinic but returns to their regular duties the next day.
- An employee is assigned to light-duty tasks for one week while recovering from a work-related back strain. (Correct answer)
- A supervisor cleans a small cut with a bandage from a first-aid kit.
- An employee is sent home for the remainder of their shift for observation after a minor incident but returns to full duty the next day.
Correct answer: An employee is assigned to light-duty tasks for one week while recovering from a work-related back strain.
The DART rate specifically tracks incidents that are severe enough to cause an employee to have days away from work, be placed on restricted work activity, or be transferred to another job. An assignment to light-duty tasks is a form of restricted work activity and is therefore included in the DART calculation.
Question 5: A safety manager is calculating the company's annual TRIR. Which of the following data points should be EXCLUDED from the 'Total Hours Worked' calculation?
- Hours worked by temporary employees from a staffing agency.
- Scheduled overtime hours worked by full-time employees.
- Paid vacation and sick leave hours for all employees. (Correct answer)
- Hours worked by salaried, office-based personnel.
Correct answer: Paid vacation and sick leave hours for all employees.
When calculating total hours worked for incident rates, only actual hours worked should be included. Time off, such as paid vacation, sick leave, or holidays, is not included in the calculation. Hours worked by temporary or salaried employees are included.
Question 6: An organization has a TRIR of 3.0 and a DART rate of 1.5 for the same period. What does the difference between these two rates indicate?
- The company has poor recordkeeping practices.
- All of the company's recordable incidents were minor first-aid cases.
- Half of the company's recordable incidents were severe enough to result in days away, restriction, or transfer. (Correct answer)
- The DART rate was calculated incorrectly, as it must be higher than the TRIR.
Correct answer: Half of the company's recordable incidents were severe enough to result in days away, restriction, or transfer.
The TRIR includes all OSHA recordable incidents, while the DART rate is a subset of those incidents that are more severe (resulting in days away, restriction, or transfer). Therefore, the DART rate will always be less than or equal to the TRIR. In this case, a DART of 1.5 is exactly half of the TRIR of 3.0, meaning 50% of the recordable incidents were of a more serious nature.
COSS - Certified Occupational Safety Specialist Incident Rate Calculations Questions and Answers
A manufacturing company with 150 full-time employees, each working 2,000 hours per year, experienced 7 OSHA recordable incidents.
What is the company's Total Recordable Incident Rate (TRIR)?