Severity/Control Risk Matrix
His co-worker manages to lower the lift, but his clothes catch fire too; both men pass out. The worker holding the voltmeter dies 14 days later.
O RCHSE integrates the degree of control and human and organizational performance factors into its risk assessment approach by developing a Severity/Control Risk Matrix. The following case study example illustrates its application. Two workers on a scissors lift perform a “non-live” installation of wiring for fans that will later be connected, energized, and inspected by a licensed electrician. As they run conduit across the ceiling, they approach a partially exposed 480-volt electrical bus bar in a bus enclosure missing an end cap. One worker attempts to use a voltmeter to test the current; the voltmeter crosses two phases of the bus bar and explodes, setting fire to his clothing and causing burns to over 35 percent of his body. His co-worker manages to lower the lift, but his clothes catch fire too; both men pass out. The worker holding the voltmeter dies 14 days later. The plant where the incident occurred had been purchased by the company 18 months prior to the incident.
It employs 170 permanent employees and 200-300 temporary employees, most from the Dominican Republic, who work during a four-month busy season. Little formal training is provided and no safety training other than what employees learn on the job. The victim was a 19-year-old Hispanic male, originally hired as a laborer/helper, who was being trained to work as a mechanic’s assistant. The employee had no training on electrical safety, and was not trained to test circuits.
As Step One to perform an initial risk assessment based on severity of hazards and controls in place, ORC HSE applies its matrix to the case study with the following results:
As Step Two, ORCHSE considers HOP issues – characteristics of underlying systems and processes – that could provoke errors or undermine controls. This includes cultural and organizational attitudes and values, management systems, process conditions, and human factors.
Value for safety not demonstrated by senior management;
Employees do not receive support for safety decisions;
High risk tolerance;
Inadequate financial resources for safety;
Low employee engagement;
Production has higher priority than safety;
Supervisors do not receive support for safety decisions; and
Personnel resources are not adequate for safety.
Management systems issues include:
Checklists not in use;
Cross-monitoring not in use;
Goals and objectives for safety performance had not been established;
Low management accountability;
Poor risk recognition training;
Potential for miscommunication;
Pre-task briefing not in use;
Pre-task planning/risk assessment not in use; and
Procedures/work instructions not adequate.
Process condition issues can include:
No emergency shutdown procedure;
Inadequate warning mechanisms; and
Inadequate work/task resources.
Finally, examples of human factors issues involving fitness for the job and task can include:
Lack of skills or education for the task;
Distraction; and possibly
Consider the case study –it’s clear how differing approaches to risk identification and assessment can lead to radically different results. An experience-based approach will not pick up on the risk involved in the case study because there is no prior history of a similar experience. A hazard-based approach, on the other hand, will give this situation significant risk priority because the workers were operating at a high elevation while exposed to high energy with low-level controls. But only the hazard-based approach combined with a focus on human factors and organizational deficiencies yields higher priority attention to the task because the workers exposed to the hazards were impacted by organizational factors that made matters worse… much worse.
Applying this HOP approach to the earlier case study would have resulted in a different risk assessment. Read Part VI for more.