Drill Down to the Root Cause to Ensure Worksite Safety After an Incident: OH&S

Drill Down to the Root Cause to Ensure Worksite Safety After an Incident: By Bobby Albright April, 2024
Tools such as the fishbone diagram and the 5 Whys technique can help worksite incident investigations identify the root causes of workplace accidents and improve safety protocols.

According to the U.S. Bureau of Labor Statistics, a worker died every 96 minutes from a work-related injury in 2022, a 5.7 percent increase over the previous year.

Worksite fatalities and incidents are preventable. If an incident occurs—including fatalities, injuries or near-misses––a vital step in preventing future incidents is identifying the direct cause, the indirect cause and the root cause during a worksite incident investigation.

The direct cause is the moment of the incident that caused the injury, illness or fatality. That could be exposure to a fume or gas, a caught-in (or between), struck by, or other incident types. The indirect cause is what may have contributed to the incident occurring but is not the primary reason for the incident.

The root cause is the underlying reason why unsafe conditions exist or why a safety procedure was not followed. Effective incident investigators use tools and interview techniques to identify the root causes.

OSHA’s comprehensive incident investigation guide provides information on the full investigative process. The following are useful techniques specific to finding the direct cause, indirect cause and root cause in an accident investigation, which is step three in OSHA’s guide.

Go Fishing
A simple and effective tool used in worksite incident investigation is the fishbone diagram. Fishbone diagrams provide a way to organize evidence collected from the scene and during interviews.

The incident problem is placed at the head of the fish. Possible contributing causes are added on the smaller “bones” listed under categories including management, equipment, process, environment, materials and people. An example of a fishbone diagram is available on the Nevada Safety Consultation and Training Section website.

Using the diagram, investigators can organize facts and information about the incident scene as well as details from witnesses and interviews, while adding subcategories as needed. Within each category, investigators can drill down to identify root causes using the 5 Whys technique explained below.

Ask Why, Then Dig Deeper
The 5 Whys interview technique was developed at Toyota and became popular in the 1970s. Toyota still uses it to solve problems today.

Click here for the link to this article as published in Occupational Health & Safety Magazine.