Share thisEvery year, we see animal research facilities moving towards more automation. Maintaining large animal colonies is labor intensive given the types and sheer number of tasks performed, such as washing and sterilizing cages, installing and disposing of bedding, feeding, and watering. Complex equipment such as tunnel washers, cage washers, conveyors, bedding dispensers, and incinerators, to name a few, are becoming necessities and much more prevalent. When working in these well equipped animal research facilities, we encounter problems in two main categories: noise and the inherent dangers of the machinery. This issue’s column discusses Lockout/Tagout, the procedures used to isolate and de-energize complex machinery so repairs or maintenance can be performed safely.
Lockout/Tagout measures are taken to prevent the release of unwanted or stored hazardous energy. If we fail to develop and follow a good Lockout/Tagout program, the result leads to some of the most grisly and often fatal accidents in the workplace. One recent example that has been in the news lately involved a monkey killed in a cage washer when she was accidently left in her cage that got loaded into the giant washer. After a twenty minute cycle of 180 degree water and caustic detergents you can imagine the horrible discovery. What if a co-worker or maintenance staff had been working to fix a jam in the conveyor feed line?
Recent data from the Bureau of Labor Statistics (for 2004, 2005, and 2006) show that fatal incidents involving struck by or contact with equipment ranked third behind falls and highway incidents.1 In addition, in 2006 alone these accidents accounted for seventeen percent of the total.1 The sad thing is that every one of these could have been easily prevented.
What do we mean by Lockout/Tagout?
Lockout/Tagout is the name we give to the program that complies with the OSHA standard for the control of hazardous energy, 29CFR1910.147.2 Briefly, this regulation applies to any employer whose employees must service or maintain machines where unexpected start up, energization, or release of stored energy could cause injury. It addresses all sources of energy including mechanical, electrical, thermal, hydraulic, pneumatic, and chemical. The principle is simple and easily understood: lockout (or tagout) the energy source or equipment prior to working on it. However, due to the different types of energy and complexity of the equipment and controls, a well thought out and detailed procedure is best.
Lockout (the OSHA-required method unless this is infeasible) refers to placing an actual lock or physical block on the circuit breaker, switch, or other energy control. Devices exist on the market for most configurations. Tagout allows a tag to be placed on equipment or controls that cannot be locked out. Exceptions are permitted where the hazardous energy can be completely controlled by the employee performing the maintenance or service. Examples would include a single electrical plug or valve right at the machine. Special procedures are also permissible where continuity of operations are essential or shut down of the system impractical such as pressurized steam, water or gas distribution lines.
The fundamental rules for a good Lockout/Tagout program are “one lock – one employee” and “you put it on – you take it off.” Sharing of locks or passing of keys should never occur, even when changing shifts. Another cardinal rule is “test it before working on it.” Even if all procedures have been followed and locks or tags placed, employees should “throw the switch” before beginning work to ensure unexpected start up does not happen. This will eliminate injuries from potential stored energy sources like batteries, capacitors, and pneumatics etc.