Incident Investigation, Recordkeeping, and Incident Rate Calculation

Why Incident Investigation and Recordkeeping Matter

Every construction employer must track workplace injuries and illnesses systematically. Accurate records protect workers by revealing patterns, satisfy federal legal requirements, and directly affect a contractor's ability to win work. Pre-qualification systems used by owners and general contractors pull your incident rates before they even open your bid. A high rate can disqualify your firm regardless of price. Conversely, a strong safety record is a competitive advantage.

OSHA's recordkeeping rule (found in 29 CFR Part 1904) requires most employers with more than ten employees to maintain injury and illness logs. Construction is not exempt. Understanding what is recordable, how to document it, and how to calculate the rates derived from those records is a core skill for any construction manager or estimator involved in project safety planning or pre-qualification packages.

The Three OSHA Recordkeeping Forms

OSHA 300 – Log of Work-Related Injuries and Illnesses. This is the running log maintained throughout the calendar year. Each recordable case gets one row. You record the employee name, job title, date of injury or onset of illness, where the event occurred, a brief description, and which category applies: days away from work, restricted or transferred duty, other recordable cases, or illness type. The log must be updated within seven calendar days of learning that a recordable case occurred.

OSHA 300A – Summary of Work-Related Injuries and Illnesses. At year-end, you total the columns from the 300 log and transfer those totals to the 300A summary. You also enter the establishment's annual average number of employees and total hours worked. A company executive must certify the 300A. It must be posted in the workplace from February 1 through April 30 of the following year so employees can see the prior year's data.

OSHA 301 – Injury and Illness Incident Report. A separate 301 form is completed for each individual case on the 300 log. It captures detailed information: employee information, healthcare provider, time of event, what the employee was doing, how the injury occurred, what object or substance was involved, and the nature of the injury. It must be completed within seven calendar days of learning of the recordable case. Workers' compensation first-report forms may substitute if they contain equivalent information.

What Makes a Case Recordable

A case is recordable when it is work-related, is a new case, and meets at least one of these criteria: results in days away from work; results in restricted work or job transfer; requires medical treatment beyond first aid; involves loss of consciousness; involves diagnosis of a significant injury or illness by a healthcare professional. First aid only — such as bandaging a minor cut, applying a non-prescription medication at non-prescription strength, or using a non-rigid means of support — is not recordable. If you are unsure, the deciding question is always: did the work environment cause or contribute to the condition?

For a scaffold fall causing a lost-time injury, the case is clearly recordable: it is work-related, it is a new case, and the worker has days away from work.

TRIR and DART Rate Formulas

Two rates are universally used to compare safety performance across employers of different sizes.

Total Recordable Incident Rate (TRIR) measures all recordable cases per 100 full-time equivalent workers.

> TRIR = (Number of recordable incidents × 200,000) ÷ Total hours worked

The constant 200,000 represents 100 workers × 40 hours/week × 50 weeks — a standard full-time year for 100 employees.

Days Away, Restricted, or Transferred Rate (DART) counts only those cases that resulted in at least one day away from work, restricted duty, or job transfer.

> DART = (Number of DART cases × 200,000) ÷ Total hours worked

Both rates are expressed as incidents per 100 full-time workers per year. Lower is better. Industry average benchmarks published by the Bureau of Labor Statistics (BLS) vary by NAICS code; construction rates are typically higher than the all-industry average. The Associated General Contractors (AGC) and BLS publish current averages you can use as comparison targets.

How Rates Affect Pre-Qualification

Owners and general contractors use pre-qualification scoring to manage subcontractor risk. Most systems ask for three years of TRIR and DART data. A TRIR above the published industry average for your trade often triggers automatic disqualification or requires a written corrective action plan before a company can bid. Estimators must factor this reality into business development strategy: investing in safety training, PPE, and supervision is not only the right thing to do — it is necessary to remain competitive.

Incident Investigation and Root-Cause Analysis

Recordkeeping tells you what happened. Incident investigation tells you why and prevents recurrence. A thorough investigation identifies three levels:

• Direct (immediate) cause: The specific unsafe act or condition that triggered the event (e.g., the scaffold plank was not secured).
• Contributing factors: Conditions that allowed the direct cause to exist (e.g., no daily scaffold inspection was performed).
• System (root) causes: Organizational failures behind the contributing factors (e.g., no written scaffold inspection procedure existed; supervisors were not trained).

A corrective action plan addresses all three levels. Each action must name a responsible party and a realistic target completion date. Actions that only address the direct cause — replacing the plank — without fixing the system failure will not prevent similar incidents.

Safety Points: Scaffold Incidents

Scaffold work is among the highest-risk activities in construction. Before any scaffold work begins, competent-person inspection is required. All workers on scaffolds must use fall protection when required by OSHA standards and must receive scaffold-specific training. Lockout/tagout procedures apply to any mechanized scaffold equipment. PPE — hard hat, non-slip footwear, and appropriate fall arrest equipment — is the last line of defense, not the first. Engineering controls and administrative controls come first in the hierarchy of controls.