Incident Investigation

General WorkSafety

May 29

An incident investigation report form is shown with a pen resting on it.

Date Posted: 05/29/2024

Incident investigation is determining the root causes of incidents, on-the-job injuries, property damage, and close calls to prevent them from occurring again. An incident investigation should lead you to the real cause of why something happened, and armed with that knowledge, you can take affirmative steps to prevent future incidents from occurring. In addition to the root cause, several causal factors may contribute to the incident. These will be evidenced in the answers to the “why” questions. Several factors may have contributed to the root cause, and correctly identifying them will help you develop a plan to mitigate the hazard in the future.

What is an Incident?

An event resulting in personal injury, property damage, equipment damage, impact to environmental resources, loss of production or product, or an event that has the potential to cause significant injury, damage, loss, or effect to environmental resources.

Why Should Incidents be Investigated?

Prevention is the purpose of an investigation. An incident investigation should:
Determine what happened.
Determine the cause or causes of the incident.
Identify any unsafe conditions, acts, or procedures.
Help management to identify practical corrective actions.
Determines whether due diligence was observed.
Show the commitment of management that an adequate investigation system is in place.

An incident investigation should not strive to determine fault or blame but to identify the primary causes of incidents so that controls can be implemented to prevent further occurrences.

Incident Investigation Steps

Preserve and Document the Incident Scene: Before anything occurs, one must ensure that the incident scene is secure and does not present further potential for environmental damage or harm to those around.

Gather Information: As little time as possible should be lost between the incident event and the beginning of the investigation. Gather basic information about the incident. Gather empirical data and interview witnesses separately and independently. A detailed report is unnecessary initially; you need enough information to understand what happened to identify initial actions. After initial actions and notifications are completed, a more focused investigation will generate much more detail and identify root causes.

Establish the Facts: Examine the incident scene, looking for things to help you understand what happened. This includes looking for dents, cracks, or scrapes in equipment; tire tracks or footprints; spills or leaks; scattered or broken parts; and other factual evidence. Photograph any items or scenes that may explain what happened to anyone not there. Photograph items that will not remain or be cleaned up (e.g., spills, tire tracks, or footprints). In addition, review records. Check training records to determine if appropriate training was provided and when training was provided. Check equipment maintenance records to determine if regular maintenance or service was provided or if there is a recurring type of failure.

Identify Contributing Factors: Contributing factors include the environment, design, systems and procedures, and human behavior.

Environmental factors include noise, light, heat, vapors, fumes, and dust.
Design factors include workplace layout, design of tools and equipment, and maintenance.
Systems and procedures: factors include lack of systems and processes, inappropriate systems and methods, training in operations, and housekeeping.
Human behavior: including carelessness, rushing, fatigue, etc.

Identify Root Cause(s): Root cause analysis (RCA) is a structured process that assists in identifying underlying factors or causes of an event, such as an incident or near miss. Understanding the contributing factors or causes and effects of a system failure can help develop actions that prevent similar incidents from happening again. The objective of the RCA is the identification of appropriate and necessary corrective and preventive measures. After that, updates/adjustments of the risk assessment and implementation of actions shall be carried out. There are five primary factors to consider when identifying the root cause(s). These are:

The Task: the nature and execution of the actual work task.
The Equipment/Material: issues with equipment or materials used for work.
Personnel: the employee's physical and mental condition and the workplace's psychosocial environment.
Management/Procedures: management failures, procedural failures, or a failure to account for employee safety and well-being. The investigation should help determine if a procedure or safety rule was not followed and, if not, why the policy, practice, or rule was not followed.
The Environment: issues with and changes in the physical work environment.

Determine Corrective Action(s): Once it is understood what happened and why, you are ready to determine how to fix the problem to avoid repeat incidents. Think about not only what is the most expedient action but also about which actions will permanently solve the issues that led to the incident. A quick, cheap fix might not be the best answer in the long run.

Implement Corrective Action(s): As soon as possible after the incident, take corrective action. Review the incident’s root causes and corrective actions with employees to ensure they understand what happened and how to avoid a repeat incident. Monitor your corrective action to ensure that it effectively prevents the recurrence of incidents and does not inadvertently create other hazards in the process.

Don’t Forget to Review Hazard Control Measures!

Review your control measures to ensure they are relevant and keep workers safe. When reviewing hazard control measures, consider the following:

Are the control measures working effectively in both their design and operation?
Are the control measures creating new problems or hazards?
Did the investigation process miss identifying any new hazards?
Are the new work methods, equipment, or chemicals making the job safer?
Are all employees following the safety procedures?
Is any additional training required?