October 2023
GM Canterbury Safety Charter
Most organisations that I know of spent a lot of time examining measures of health and safety performance. The most common can be the recordable injury rate, or Loss time injury rate, or incident rate etc. The thing that these have in common is that they are all measured after an accident/incident has occurred.
The good news is that lag indicators are very clear and objective, in that they are based on actual measurable events. The bad news is that different organisations may differ in their definitions of what is a recordable event. The other problem is that not all events may be recorded. In this regard, the validity of these measures can be questioned.
The other problem is that lag indicators can lead to shutting the barn gate after the horse has bolted, and they cannot be effectively used to predict future events. This is because loss time injuries are usually less common, random, and historical.
The move more recently has been toward measuring lead indicators, which are measures of activities that an organization takes to prevent injuries. These can be toolbox talks, health and safety training, updating of risk registers etc. In fact, a measure of any health and safety activity that is not about recording incidents can potentially be called a lead Indicator. Because this definition is so broad, lead indicators are not consistent or objective.
A strong measure of health and safety performance needs to be objective, that is based on observable events not subject to human bias. It must be clear and easy to communicate, and provide information that can prompt action. Even better if it can be predictive and allow historical trends to provide information of the probability of future events.
This is where HECA comes in, and time to brush off your high school physics. Energy is measured in units called Joules, or kilojoules (thousands of Joules). One definition of energy is simply the amount of damage it can do. A hazard with fewer than 500 Joules of energy can cause a first aid injury. One with up to 1500 Joules can cause a medical injury, and greater than 1500 Joules can result in a serious injury or fatality. High Energy Hazards are those with more than 1500 Joules of physical energy. For a bit of context, a 100kg load falling 1m has 1000 Joules of energy.
HECA stands for High Energy Control Assessment. It is built on the assumption that safety performance is best measured by the control of High Energy Hazards. HECA is simply the percentage of high energy hazards with a corresponding direct control.
HECA has two components to be considered. The first is the identification of high energy hazards, and the second is whether there is a corresponding direct control over the hazard. The second part is a binary choice. Either there is exposure to the hazard (E), or there is a direct control (DC).
Now comes a bit of mathematics. The Total (T) is the number of high energy hazards identified, controlled or not.
Total = E + DC
Then HECA = DC/Total X 100
If HECA is 100%, then all of the high energy hazards have a direct control.
If HECA is 50%, then only half of your high energy hazards have a direct control.
High energy hazards are identified by the type of energy they contain.
- Gravity: suspended load or fall from height
- Motion: Mobile plant and machinery, traffic,
- Mechanical: Heavy rotating equipment, mechanical tools
- Heat: Steam, high temperatures, fire
- Pressure: Explosion, excavation of trench,
- Electrical: Contact with source, arc flash
- Chemical/Radiation: High dose of toxic chemicals or ionizing radiation
The direct controls must meet three criteria.
- Targeted to the high energy hazard. Ie fall arrest system for work at heights.
- Effectively mitigates high energy.
- Must be effective even if there is unintentional human error. Training and signage are not direct controls because they are vulnerable to human error.
Hazard ID/Risk assessment tasks now require a couple of extra columns to do a HECA assessment.
|
Hazard |
Energy Source |
High Energy |
Direct Control |
HECA |
|
Suspended Load |
Gravity |
yes |
No mitigation |
E |
|
Suspended pipe |
Gravity |
yes |
Cribbing used |
DC |
|
Overhead lines |
Electrical |
Yes |
Line de-energised |
DC |
|
Heavy Vehicle traffic on site |
Motion |
yes |
No energy mitigation and workers on foot vulnerable to human error |
E |
|
Elevator shaft |
Gravity |
yes |
Engineered barricade |
DC |
The HECA score for this particular assessment would be 3/5 X 100 = 60%
HECA is neither a lead nor a lag indicator, but more simply a method of monitoring and evaluating current practices for mitigating high risk work. It can be easily measured and communicated, although there will be some variation around assessing high energy and direct controls. It also directs action towards the areas where there is exposure to high energy risks.
Tracking HECA over time for a particular site/job will demonstrate how exposure of workers to high-risk work can be improved. Thinking about hazards in terms of their energy may also assist in identifying high risk conditions which would otherwise be overlooked.
You may not want to throw out your current performance measuring systems, but HECA might be something to think more about.
