How to Calculate OSHA DART Rate: A Comprehensive Guide
Safety managers and business owners rely on specific metrics to gauge the effectiveness of their safety programs. One of the most critical Key Performance Indicators (KPIs) in workplace safety is the DART Rate. Unlike the Total Recordable Incident Rate (TRIR), the DART rate specifically focuses on more severe injuries that affect an employee's ability to perform their job normally.
What is the DART Rate?
DART stands for Days Away, Restricted, or Transferred. It is a mathematical calculation mandated by the Occupational Safety and Health Administration (OSHA) to track the number of recordable injuries and illnesses per 100 full-time employees that resulted in:
- Days Away: The employee missed one or more days of work.
- Restricted: The employee was at work but could not perform their routine job duties.
- Transferred: The employee was moved to a different position temporarily due to the injury.
A lower DART rate indicates a safer workplace, while a high DART rate suggests that injuries are not only occurring but are severe enough to impact workforce productivity.
The DART Rate Formula
The standard formula used by OSHA to calculate the DART rate is relatively straightforward. It normalizes your injury data to compare companies of different sizes (standardized to 100 full-time employees).
Understanding the Variables:
- Total DART Incidents: This is the sum of columns H (Days Away) and I (Job Transfer or Restriction) from your OSHA 300 Log.
- 200,000: This constant represents the equivalent of 100 employees working 40 hours per week for 50 weeks a year (100 × 40 × 50 = 200,000).
- Total Hours Worked: The actual total number of hours worked by all employees (including full-time, part-time, seasonal, and temporary) during the calendar year.
Step-by-Step Calculation Example
To understand how to calculate OSHA DART rate in a real-world scenario, let's look at a manufacturing company:
XYZ Manufacturing had a challenging year. Reviewing their OSHA 300 Log, they found:
- 2 injuries resulting in days away from work.
- 3 injuries resulting in restricted duty or job transfer.
- Total DART Incidents = 2 + 3 = 5.
- Their total employee hours worked for the year was 450,000 hours.
(5 × 200,000) ÷ 450,000
1,000,000 ÷ 450,000 = 2.22
XYZ Manufacturing has a DART rate of 2.22.
Why is the DART Rate Important?
Calculating your DART rate is not just a regulatory exercise; it has significant business implications:
- Regulatory Scrutiny: A rate significantly higher than your industry's average (based on NAICS codes) can trigger OSHA inspections.
- Insurance Premiums: Workers' compensation providers use this metric to assess risk. A high rate often leads to higher premiums.
- Contract Bidding: Many general contractors and clients require safety statistics during the bidding process. A high DART rate may disqualify your company from lucrative contracts.
How to Lower Your DART Rate
Improving your DART rate requires a proactive approach to safety culture:
- Return-to-Work Programs: Implement aggressive return-to-work programs that accommodate restricted duty, ensuring employees remain productive even if they cannot perform their standard tasks.
- Ergonomic Assessments: Since strains and sprains often lead to restricted duty, improving ergonomics can drastically reduce DART incidents.
- Root Cause Analysis: Investigate every DART incident thoroughly to prevent recurrence, rather than just treating the symptom.
TRIR vs. DART: What's the Difference?
While TRIR (Total Recordable Incident Rate) counts all OSHA-recordable incidents (including those requiring only medical treatment beyond first aid), DART only counts the incidents that disrupt the work schedule. Therefore, your DART rate will always be lower than or equal to your TRIR. The ratio between the two can highlight the severity of injuries occurring at your facility.