Understanding High Energy Incidents in Arboriculture: How the EEI Safety Classification and Learning Model Helps Prevent Serious Injuries and Fatalities

By Tim Walsh

In arboriculture, keeping our teams safe is more than a priority, as priorities can change, it is our leading value. Unfortunately, serious injuries and fatalities – or SIFs – still occur, and the top four causes include falls from elevation, contact with objects (or struck-by incidents), electrical contact and transportation-related incidents. These types of incidents are especially hazardous when they involve the transfer of high amounts of energy to a worker – specifically, when more than 500 foot-pounds of energy are transferred during an incident. The EEI Safety Classification and Learning Model uses this “high energy” threshold to help us understand and learn from these dangerous events.

What Does “500 ft-lbs of Energy” Mean?

Energy, measured in foot-pounds – or ft-lbs – is a way to express the force or impact that an incident has on a worker. When more than 500 ft-lbs of energy is transferred to someone during an incident, we call it a “high energy” event. This level of energy transfer can cause catastrophic injuries or even fatalities. The EEI SCL model uses this threshold to classify incidents, helping us see which accidents are most dangerous and where we need to focus our safety improvements. Additionally, and a topic for a future blog, it also addresses controls, but more on that later.

Contact with an Object/Struck-By Incidents

The most common cause of serious injury is being struck by a moving object. In arboriculture, this can happen when heavy branches, even whole trees are in motion. When these objects hit a worker, the energy transferred can surpass 500 ft-lbs very quickly, depending on the object’s weight and speed. The EEI SCL model helps us see that these incidents are high energy events, highlighting the potential for severe injury. One additional note is that incidents related to chippers also fall into this category.

By applying the EEI SCL model, teams can review incidents where a worker was struck by an object and assess the energy involved. Was the equipment being used properly? Were safety zones clearly defined? Were workers wearing the appropriate personal protective equipment? The answers to these questions not only help explain the severity of the incident but also guide improvements in safety procedures, such as better barriers or more effective communication during critical operations.

Falls from Elevation

Another major hazard of serious injuries in arboriculture is falling from a height. Whether it’s a fall from a tree or aerial lift, the energy transferred to a worker during a fall can easily exceed 500 ft-lbs. For example, if an arborist falls several feet from a tree, the impact energy can be enormous, overwhelming the body’s ability to absorb the force. The EEI SCL model helps us understand that these high-energy falls are not just a result of height, but also of the acceleration and momentum that build up during the fall.

Using the EEI SCL model, we can analyze the specifics of a fall: What was the height? What equipment was used? Were proper fall arrest systems in place? By classifying falls that exceed the high energy threshold, teams can learn what went wrong and how to prevent similar incidents. This might lead to better harness designs, improved training on fall prevention, or stricter adherence to safe work practices when working at heights.

Electrical Contact

Electrical hazards are a unique and deadly threat in arboriculture. Contact with power lines or other energized equipment can deliver a massive dose of energy directly into a worker’s body. Even a brief contact can transfer energy well above the 500 ft-lbs threshold, leading to life-threatening injuries or death. The EEI SCL model recognizes these types of incidents as high energy events that require special attention.

When an electrical contact incident occurs, the EEI Safety Classification and Learning Model encourages a thorough review of the event. Was there adequate clearance from power lines? Were the workers properly trained in identifying and avoiding electrical hazards? This deep dive into the incident helps companies refine their safety protocols, from enforcing stricter distance rules to providing better insulation and protective gear. Ultimately, the EEI model helps ensure that electrical hazards are treated with the utmost seriousness and that lessons are learned to prevent future tragedies.

Transportation-related Incidents

Transportation-related incidents – such as vehicle collisions, rollovers, or accidents involving heavy equipment – are another leading cause of SIFs in arboriculture. When a worker is involved in such an incident, the energy transferred from a moving vehicle or equipment can exceed 500 ft-lbs, resulting in severe injuries. The dynamics of these accidents are complex, often involving high speeds, heavy machinery, and limited maneuverability in tight spaces.

The EEI SCL model assists in dissecting these incidents by quantifying the energy involved. This quantitative approach can help determine whether a particular transportation incident was a high energy event, which in turn signals a need for better control measures. For instance, companies may look into improving vehicle design, reinforcing safety barriers, or enhancing operator training. By learning from these high energy incidents, organizations can implement changes that reduce the likelihood of similar events in the future.

The Role of the EEI Safety Classification and Learning Model

The EEI Safety Classification and Learning Model is more than just a way to measure energy – it’s a tool for continuous improvement. When an incident exceeds the high energy threshold of 500 ft-lbs, it triggers a detailed review process. This review examines the factors that led to the incident and how the energy was transferred to the worker. By classifying these events, the model helps safety managers pinpoint vulnerabilities in their operations.

This learning model also promotes a culture of open communication and shared knowledge. Every high energy incident is an opportunity to learn and improve. The insights gained can be used to update training programs, refine safety protocols, and enhance equipment designs. In this way, the EEI Safety model not only helps prevent future incidents but also builds a stronger, more resilient safety culture within the arboricultural industry.

Conclusion

The top four causes of serious injuries and fatalities in arboriculture – falls from elevation, contact with objects, electrical contact and transportation-related incidents – are all tied together by the energy transferred to a worker during an accident. When that energy exceeds 500 ft-lbs, the risk of severe injury or death rises dramatically. The EEI Safety Classification and Learning Model provides a clear framework to understand these high energy incidents and, more importantly, to learn from them.

By using this model, companies can analyze what went wrong, make the necessary adjustments, and ultimately protect their teams more effectively. In a field as challenging as arboriculture, embracing tools like the EEI Safety model is not just smart – it’s essential. Through continuous learning and improvement, we can work together to reduce risks, save lives, and ensure that every worker goes home safely at the end of the day.