Control Systems / Network Infrastructure

When LOTO isn’t the only answer

In this installment of Automation Zone, alternatives to lockout/tagout can offer safety as well as savings.

By George Schuster & Jimi Michalscheck, Rockwell Automation

When OSHA released its latest annual list of the 10 most-cited workplace safety violations, few people likely were surprised to see lockout/tagout (LOTO) make the list yet again.

For 2015, LOTO came in at No. 5. That’s the same spot it held 10 years ago, although the actual number of cited violations has dropped markedly from 3,711 in 2005 to 3,002 in 2015. And although no safety violation is excusable or defensible, it’s easy to understand why LOTO has become such a perennial problem.

The LOTO procedure, in which maintenance workers must remove power sources to a machine before they service it, can be both time- and labor-intensive. This can take a toll on productivity and create a strong incentive for workers to bypass LOTO when they need to perform certain maintenance or repair tasks, especially on lines where stoppages such as machine jams frequently occur.

Furthermore, some types of diagnostic and setup work require active power sources, leaving maintenance technicians with no option other than to bypass LOTO to complete their tasks.

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. The use of alternative measures can help reduce the likelihood of maintenance technicians attempting to bypass critical safety procedures; these measures can help reduce safety risks and boost productivity at the same time.

Openings for loto alternatives

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.

Imagine a manufacturer with 350 production days per year and a production value of $1,000 per minute that experiences an average of 15 downtime events per day. Each downtime event has a MTTR of 12 minutes per event. If a LOTO alternative can shave just 30 seconds off that MTTR, the manufacturer would save more than $2.6 million in downtime per year ($500 in additional production value per 30 seconds × 15 downtime events per day × 350 production days = $2.625 million).

Goal: Zero LOTO violations

LOTO is by no means the only repeat offender on OSHA’s annual top 10 violations list. However, given the emergence of safety standards that allow for alternatives to be used in place of LOTO in certain instances and the contemporary safety technologies that can be employed, manufacturers can crack down on LOTO violations while enhancing safety and productivity in the process.

A final note: While it may be possible to engineer out many servicing activities with well-engineered safety procedures and high-performance hardware, it’s recommended that users always follow lockout/tagout regulations when performing service on equipment where no company-approved safe alternatives exist. Lastly, users should assure themselves that all maintenance and servicing procedures are safe, effective, and properly tested according to good practice and regulation.