By Staff

The number of possible types of injuries occurring when performing work on energized equipment is impossible to count.  They can range from burns, to electrical shock, to crush injuries, to cuts/lacerations, and beyond.  In an effort to help eliminate some of these injuries, the OSHA standard for Control of Hazardous Energy (29 CFR 1910.147), more commonly known as lockout/tagout (LOTO), went into effect in 1989.  The purpose of the standard is to help companies establish the practices and procedures needed to prevent injury to workers when they are performing maintenance activities to equipment requiring an energy source.  Any company in violation of the standard is subject to a fine.  It is estimated that in 2013, there were approximately $14 million in federal and state fines, and lockout/tagout was the 5th most frequently violated standard in 2015.

However, the REAL goal of the standard is to keep people safe.  So how is the standard violated?  It can happen in many ways, but this blog takes a look at one specific incident to better understand  how it can happen.  This analysis is based on a case study presented in the article “Lockout/Tagout Accident Investigation” from the August 2014 issue of Occupational Health & Safety.

In this incident, several contractors were working on a project involving a particular switchgear.  Many of these contractors had performed lockout/tagout for the switchgear box related to the projects that they were working on.  After the work began, a worker from a different contractor was asked to clean out part of the switchgear.  Unfortunately, an arc flash occurred when he reached in the switchgear, resulting in burns to his hand and a blow-out injury to his knee.  Fortunately, the employee survived, recovered, and was able to return to his normal life.

A Cause Map can be built to analyze this issue.  The first step in Cause Mapping is to determine how the incident impacted the overall goals.  For this incident, the safety goal was the most obviously impacted goal due to the injuries that the worker sustained.  The goal is always for employees to leave the workplace in the same health in which they arrived.  Additionally, the regulatory goal was impacted since the injuries were severe enough that they were classified as recordable.

The Cause Map is a visual representation of the cause-and-effect relationships that contributed to the incident.  Starting with the impacted safety goal, ‘why’ questions can be asked to identify the key factors that caused the problem.  In this case, the injuries were caused by the fact that an arc flash occurred when the worker reached into the switchgear and he was not wearing personal protective equipment.  The worker was probably not wearing PPE because he thought that the switchgear was de-energized, and this was an effect of the fact that there were locks and tags already on the switchgear.  The arc flash was a result of the fact that the circuit breaker was energized when the worker reached in to clean it.  The circuit breaker was energized because of three factors: a different contractor had put it back in service the night before, the circuit was not tested by the worker, and the worker didn’t do his own lockout procedure.  Each of these problems can be further analyzed to reveal problems with communication, adding the task at the last minute and not including every task in a job safety analysis.

For this situation, and many like it, eliminating a cause anywhere on the map could have minimized the risk of the incident occurring.  For example, had the worker taken the time to put on protective equipment or test the circuit breaker, he might not have been injured.  Similarly, had the other contractors taken the time to update their locks/tags and ensure that they had communicated that the circuit had been reenergized to all interested parties, the worker might not have been injured.  This example demonstrates that having a lockout/tagout procedure is the first step in avoiding injuries.  Ensuring that the procedure is followed in combination with other safety standards is also important to minimize the risk of injury.