The LOTO procedure, in which maintenance workers must remove power sources to a machine before they service it, is time- and labor-intensive. But there are ways round the procedure say George Schuster and Jimi Michalscheck from Rockwell Automation.
Fortunately, advances in safety standards and technologies have created opportunities for manufacturers and industrial operators to use alternative measures in place of LOTO for certain minor servicing tasks, they say in Plant Services.
Two separate standards provide for the use of alternative safety measures: OSHA standard 29 CFR 1910.147 outlines alternative measures that can be used in certain circumstances to safeguard machines and devices without having to completely cut off the power source, allowing authorized workers to perform a prescribed service. ANSI/ASSE standard Z244.1-2003 also allows for the use of alternative measures in place of LOTO for tasks that are considered “routine, repetitive, and integral” to the operation of equipment during production.
It’s important to note, however, that these two standards aren’t fully harmonious. For example, the ANSI standard allows for alternative methods in certain situations where the OSHA standard would still require LOTO. The best approach for dealing with these discrepancies is to make sure the LOTO alternative complies with both of them.
Any alternative measure used in place of LOTO must first be carefully assessed – as part of a comprehensive risk assessment – for its effectiveness in the context of the machine’s configuration, the safety measure’s reliability, employee training, and other factors. If the measure doesn’t offer protection as effective as LOTO, it should be considered noncompliant and therefore insufficient to replace LOTO.
Benefits of loto alternatives
Alternative safety measures that meet OSHA and ANSI requirements can help enhance workplace safety by reducing opportunities for maintenance technicians to put themselves at risk. At the same time, the technologies used in place of LOTO can help improve productivity by reducing the need for maintenance workers to shut down and restart machinery during minor servicing.
For example, safe-speed technologies can allow a maintenance technician to open a machine’s safety door and make adjustments while production continues at a reduced speed. The technician can watch the direct results of adjustments as they’re made rather than having to continually shut down and restart the machine for each adjustment until the issue is resolved.
Zone control is another LOTO alternative that can provide safety and productivity benefits. A maintenance technician can use zone control to stop or slow production in a designated zone while production in the other zones continues at normal speeds. The technician can then enter the stopped or slowed zone to carry out permitted tasks.
In both cases, the technologies used in place of LOTO help reduce the incentives for a maintenance worker to bypass the safety system while also reducing mean time to repair (MTTR), which can have a significant impact on productivity. In fact, alternative measures can help reduce MTTR in increments that, when accumulated over time, can deliver significant savings to the bottom line.