Managers and safety professionals from manufacturing firms tend to believe that their machinery and equipment is well-guarded, but reliable data and professional experiences prove that machine guarding problems continue to be common, ongoing sources of risk.
"It is very important that you have someone who is familiar with safety circuits and the integration of safety equipment to evaluate the machine control and determine the proper points to interface the guarding that will result in controlled, reliable operation. They also must eliminate the possibility that a machine will cycle with an unsafe condition in the machine control or the safety device," says Steve Melcher, safety controls engineer at Omron Automation & Safety.
Consider the following:
• During 2010, 24 percent of OSHA's most commonly cited standards for the manufacturing industry dealt with machine guarding violations. Those 20,000-plus violations led to more than $6 million in proposed penalties.
• There were nearly 6,000 occupational amputations in the U.S. during 2009 (most recent data available). Many of them were consequences of improperly guarded equipment or interrelated lockout violations.
• Machine guarding specialists and consulting safety professionals commonly find multitudes of violations in machine guarding standards during assessments of client operations.
"We've found that one of the main problems with people performing their own guarding is doing it correctly and safely," continues Melcher. In our experience, over 90 percent of the guards that have been installed by customers or their maintenance people-or by other contractors-are not always properly installed, enabling someone to access the hazard(s) around or through the guarding.
The Leading Suspects
Chris Soranno, safety compliance manager for the Machine Services Division of Omron Automation & Safety, pinpointed what he believes are the five principal machine guarding problems:
1. Lack of understanding of requirements
2. Improper design or installation
3. Failure to consider all risks
4. Inadequate controls to assure that guards are adjusted and maintained
5. A belief that the OEM is responsible for guarding the machine
Machine guarding standards may seem straightforward and easy to understand, but they are more nuanced than would appear upon first examination. There is a tendency to focus on OSHA standards exclusively and not consider the wealth of applicable consensus standards that are useful. According to Soranno, this is a mistake.
First, OSHA standards are not as simple as many think, and many designers and installers have not taken the time to learn and apply the recent changes. Those partially help explain why there were more than 20,000 citations issued in 2010. Second, consensus standards are important for several reasons. They represent the most current thinking and contemporary technology with regard to machine guarding, and as such, adherence helps ensure the highest level of protection for workers. Moreover, consensus standards can be enforced and used against employers in litigation. That alone should have those responsible for machine guarding looking beyond OSHA as the be-all, end-all. Omron offers a seminar called Skill Builders to groups interested in learning some of the issues involved in risk assessment and machine safeguarding. Details can be obtained by calling our Anaheim, CA facility at (714) 693-1041."
Problems relating to improper design or installation may be due to a lack of understanding. Inexperienced designers and installers, as well as others who do not have current knowledge of machine guarding requirements, are prone to errors and omissions. According to Soranno, in-house maintenance generalists are particularly vulnerable when it comes to installation. This is compounded by lack of oversight, a problem that also impacts designers; in both cases, the individuals involved are often considered the final word on a matter with which they are not fully informed.
The formal risk assessment that is necessary for comprehensive machine guarding often never takes place. Inputs are necessary from operators, maintenance personnel, supervisors, engineers, OEMs, and safety professionals-not just the guard designer. The idea that any designer can independently anticipate all potential hazards associated with equipment setup, operation, inspection and maintenance is dubious. Comprehensive lockout planning and execution is required in situations where workers must access areas inside machine guards.
Maintenance is critical. Even well-designed guards and devices must be properly adjusted and require inspection and maintenance to ensure that they continue to perform intended functions. As a practical matter, employers cannot begin to ensure that they meet the many machine guarding requirements without an effective inspection program conducted by well-trained personnel.
Finally, don't abdicate responsibility. Many purchasers of machine tools and industrial equipment mistakenly believe that the OEM is responsible for properly guarding the equipment that it delivers. While an OEM has many safety responsibilities as defined in ANSI standards, U.S. regulations hold the employer responsible for machine and equipment guarding.