Lockout Basics
- By L. Tyson Ross, P.E., CSP
- Sep 01, 2008
To encourage lockout, component manufacturers are now incorporating means of lockout into the device design so tagout will not be an acceptable alternative.
It is tempting to think in simple terms about lockout/tagout—that you merely need to power down a machine and put a lock through the deenergized disconnect to achieve safety. The reality is that it’s not that simple, and it’s dangerous to think otherwise.
Through OSHA (if nothing else), companies have an obligation to provide a safe working environment for their employees. They must be committed to protecting the health and safety of each employee as a priority of the company. In terms of lockout/tagout, OSHA regulation 1910.147 explains the control of hazardous energy.
“The servicing and maintenance of machines and equipment in which the unexpected energization or start up of the machines or equipment, or release of stored energy could cause injury to employees. This standard establishes minimum performance requirements for the control of such hazardous energy.”
Examining the OSHA 1910.147 document, it quickly becomes apparent that the document’s authors believe that the best way to prevent injuries from unexpected energy is to remove the energy from the equipment and prevent it from returning to the equipment while it is being serviced. This is accomplished through a comprehensive lockout/tagout policy or procedure.
Lockout Policies and Procedures
An effective hazardous energy control program is not a haphazard set of guidelines. Instead, it needs to be driven by company policy and instilled into each employee. The policies set by a company create the environment in which an employee lives his daily work life. A culture that encourages a methodical and consistent approach to servicing equipment, including lockout, will result in fewer injuries or lost time incidents than an environment that stresses lost production.
Once a company policy is in place, the next step is the procedure. What are the characteristics of a successfully implemented hazardous energy lockout/tagout plan?
First, begin by creating a simple inventory list detailing the machines, equipment, and processes that expose employees to hazardous energy. This process may require an audit of the plant and is an excellent time to engage all affected parties. Potential personnel to include in this audit are the plant health and safety manager, engineering, tradesmen, machine operators, and others. Because employees can be so used to their daily routines that they ignore hazards, an engineering firm or safety consultant also can lead the official inventory. The list needs to include some key information, such as the machine name, the types of hazardous energy associated with the machine, the machine location within the plant, and the process that the equipment performs.
Next, using the list generated, list all required energy isolating devices associated with each piece of equipment. This may seem like an obvious step, but it requires you to look at the equipment again to determine the potential methods that can be used to remove hazardous energy from the equipment. You may be surprised by the results.
For example, after an energy isolation audit, an employer uncovered an embarrassing surprise. One particular piece of equipment had an electrical disconnect at the main panel, as well as pneumatic circuits associated with it. During the audit, it was discovered that the nearest air isolation valve associated with the machine was located at the main plant air header line. The main plant air line was located 25 feet above the floor, the main isolation valve was located 24 feet, 6 inches above the plant floor, and there was no visible means of accessing the isolation valve without a sky lift. This circumstance existed ever since the equipment was installed, but it was an enlightening discovery brought about by simply trying to list all energy isolating devices associated with the machine.
Following the listing of all required energy isolating devices, specific procedures must be developed for the lockout of the equipment. The procedure should include the following:
• Proper equipment controlled shutdown
• Energy isolation
• Blocking, securing, or relieving stored or residual energy (including gravity)
• Placement of the lockout/tagout devices
A key part of the development of the procedure is the creation of the lockout placard and tagged lockout points. This is only one piece of the procedure, however, and it should be not only systematic, but also communicated to all employees. Training on how to execute the lockout procedure is essential to developing a safety-conscious culture within an organization. The procedure should cover not only how to apply locks to the equipment for lockout/tagout, but also the proper procedure on how to remove locks and how to apply power to the system after lockout.
This article originally appeared in the September 2008 issue of Occupational Health & Safety.