No, we are not talking about a new state lottery. We are talking about Lockout/Tagout, the process by which equipment is put into a safe condition so repairs or maintenance can take place. Forensic crime laboratories are becoming more automated and complex every year. Sophisticated equipment such as automated pipetting systems, evidence drying cabinets, fuming chambers, centrifuges, and ultra-low temperature freezers are commonplace necessities. As our facilities become more efficient and complex, we must stay alert to the intrinsic dangers.
Although considered necessary mostly in large manufacturing and production plants, Lockout/Tagout is needed whenever equipment needs servicing, which is everywhere. Lockout/Tagout measures are taken to prevent the release of unwanted or stored hazardous energy. Failure to follow good Lockout/Tagout procedures often results in some of the most gruesome and often fatal accidents encountered in the workplace. Keep reading to learn how you can design and implement a successful Lockout/Tagout program for your facility.
When thinking about why Lockout/Tagout is important, one television commercial comes to mind. Remember the one where the handyman husband has just finished installing a new garbage disposal under the kitchen sink but dropped something into it. As he is trying to fish it out with his arm inserted up to the elbow his wife enters the kitchen, goes to turn on the light and asks which switch to flip. Now, being a capable electrician and handyman at home, would you want to bet your arm on which switch to flip?
During the period 1982–1997 NIOSH (National Institute for Occupational Safety and Health) found that 82% of fatal incidents involving maintenance or repair to equipment resulted from a failure to completely isolate or dissipate the energy source.1 In addition, a short four years between 1992–1996 saw accidents from being caught in machinery kill almost 750 workers while another 5,000 lost limbs from amputation.2 Sadly, every one of these could have been easily prevented. By implementing a good Lockout/Tagout program you will ensure that your facility does not experience an ugly accident or worse.
What is Lockout/Tagout?
Lockout/Tagout is a series of steps taken by employees to isolate, dissipate, or otherwise prevent unexpected start up or energizing of equipment that could cause injury. The premise is simple and straightforward; however, detailed planning and intimate knowledge of the equipment is paramount for implementation. For example, say a centrifuge needs servicing. Before the maintenance employee can begin work, he must make sure the equipment can not be turned on by tripping the circuit breaker and then placing a lock on the switch so someone else does not energize the unit while it is being serviced. It may be as simple as pulling the plug, but many large items are hard-wired and it may not be this simple. In addition, there may be other dangers, such as stored energy.
Different Types of Hazardous Energy
A good Lockout/Tagout program is exhaustive and meticulously detailed. Autoclaves, centrifuges, and other automated equipment are capable of injuring employees in numerous ways. This is because there are several forms of hazardous energy.
- Electrical energy is most common yet still the cause of many injuries. Often overlooked are electrical storage devices such as batteries and capacitors.
- Thermal energy, either high temperature (e.g. steam) or low (e.g. liquid nitrogen) is also easily recognized. Mechanical work, chemical reactions, electrical resistance, and radiation can also produce thermal energy.
- Potential energy is energy stored in pressure vessels (e.g. compressed gas cylinders), hydraulic systems and pneumatic systems, and mechanical devices (e.g. springs).
- Kinetic energy is associated with moving mechanical parts usually resulting from the release of potential energy.
Most automated equipment will contain more than one form of hazardous energy. Thus, a thorough understanding of its operation and a detailed Lockout/Tagout procedure is needed.