July 2015Published Article

Lockout/Tagout: Safe is Not Necessarily Enough, According to OSHA

Wisconsin Business Voice

A confusing walk through the rules, exceptions and international differences

In the April Edition of Wisconsin Business Voice, Wisconsin Safety Council Director Janie Ritter identified the need for consistent machine safety measures across national borders. There are at least two cases pending in Wisconsin where an employer’s multimillion dollar machine has been determined by OSHA not to comply with OSHA lockout standards.

The problem in these cases is not in safety during production, but safety during maintenance. Some machines are designed so electrical, hydraulic or other energy supply is needed during maintenance to (slowly) move machine parts. But maintenance while the machine is energized may violate the U.S. OSHA lockout standard. This conflict in design and the law may arise from international differences.

The most significant difference between lockout requirements in the U.S. and Europe (which generally applies ISO requirements) is the required method to isolate machinery from its energy source during maintenance. In Europe, ISO requirements may allow for lockout compliance using electrical control systems with a “high level of design reliability.” For example, a machine may have a switch interlocked to a guard, such that when the guard is open the machine cannot run. Even though the power is still flowing to the machine, this may be compliant with ISO, so long as this control system has a high level of design reliability.

OSHA regulations in the U.S., however, do not allow employers to rely only upon design reliability of control systems. OSHA requires that it be impossible to re-energize the equipment when locked out. OSHA defines an energy isolation device to exclude “push buttons, selector switches and other control circuit type devices.” The assumption built into the OSHA regulatory scheme is that
switches can, and do, fail.

Muddying the waters further is the exception in U.S. OSHA’s lockout standard for “minor servicing.” Under this exception, physical disconnection is not required for “minor” servicing activities, provided the work is performed using alternative measures which provide “effective protection.” There are a lot of challenges to meeting the definition of “minor” in that exception. But the point is; an interlocked switch, such as that described earlier, may meet the effective protection requirement of the minor servicing exception, but not the rule itself. If the machine requires an energy supply during non-minor servicing, the employer has a problem. Push buttons, selector switches and other control circuit type devices, like the interlocked guard in the example, will generally not be safe enough, according to OSHA.

This places U.S. employers in a difficult spot. A multimillion dollar machine may be perfectly legal to operate, but impossible, or impractical to maintain, according to OSHA requirements. So an employer may find itself in the position of having to defend the safety of its brand new state-of-the-art machine. One legal defense to OSHA’s position is found in the language of the regulation itself. The regulation “scope” statement says it covers “servicing and maintenance of machines in which the unexpected energization, or start-up of the machine or equipment, or release of stored energy, could harm employees.” OSHA believes this requires the employer to demonstrate there is no possibility of unexpected energization or start-up. But, in one case, the fact that the machine had a horn that would sound before start-up, was deemed to refute the “unexpected” startup requirement, and the OSHA citation was vacated.

Unfortunately, given the confusion between the law in the U.S. and other jurisdictions, it is not always clear whether a machine is OSHA compliant. There may be defenses to OSHA’s conclusion, but most employers just want to follow the law, not hire a lawyer
to demonstrate that the machine – which was recently purchased, with all the bells and whistles and at a high price – complies with the law. The obligation should be on the manufacturer of the machine but their focus is on safety during normal operation, and the international differences on lockout are confusing.

Until the law changes, U.S. manufacturers should consider involving maintenance and safety managers in machine purchase decisions and ask the simple question: Can maintenance practically be completed with the machine locked out so energy sources are disconnected, not just turned off by buttons, switches or other control circuit devices? If not, consider Janie Ritter’s helpful suggestions from her column on Safety Excellence in the April edition.

To read the full July issue, click here.

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