Pamela J. Cordier
March 1, 2006
During the period of 1992-99, according to the Bureau of Labor Statistics (BLS), there was an average of more than 21 fatal and more than 11,000 non-fatal workplace amputations annually. During 1996-97, amputation injuries were reported as the most costly compensation claims, averaging $18,120 each. Additionally, as computed for the year 1999, non-fatal amputation injuries averaged 31 or more days away from work. The majority of these were almost certainly the result of improper lock out tag out (LOTO) methods or ineffective or missing machine guards.
While amputations may be seen as the tip of the iceberg, countless other fatalities or non-fatal serious injuries are caused by inadequate guarding or the absence of protective barriers around in-running nip points, rotating shafts, mechanical shears, or belts and pulleys.
A source of frequent citations
OSHA requires guarding of any machine part, function, or process that may cause injury to operators or others. This standard has been around since the inception of OSHA and yet remains on its list of most frequently cited regulations (29 CFR 1910.211-222 Sub-Part O). OSHA is extremely concerned about this lack of compliance and has made machine guarding part of its National Emphasis Program.
Workplace injuries and fatalities involving moving machine parts are such a significant risk that the National Institute for Occupational Safety & Health (NIOSH) joined with the American National Standards Institute (ANSI) as well as other business, labor, and insurance partners in 2002 to study the problem. They are now finishing a project to evaluate the effectiveness of an ANSI-issued voluntary guideline to prevent such injuries. The ANSI Guideline ANSI B11 TR3 outlines a methodical process for employers to assess facility hazards that contribute to these types of injuries.
Machine guarding is very important in any successful safety program for equipment with moving parts that may lacerate, burn, crush, or amputate. All such injuries can be very severe and may cause time away from work, disfigurement, and even death. It is often noted that machinery cannot distinguish between wood, steel, paper, or poly and what is part of your body. Operation of this equipment is extremely dangerous and wherever these conditions exist, the hazards must be eliminated or controlled with proper machine guards.
Effectiveness depends on application
The methods and types of guards are varied and effectiveness is dependent on the configuration or nature of the machine hazard. Belts and pulleys, flywheels and gears, shafts and spindles, chains and sprockets, counterweights and even gravity all transmit power.
To identify hazardous equipment parts, look for nip-points, shear-points, impact or crushing areas, cutting surfaces, points of entanglement, puncture-points, abrasive surfaces, flying particles, and any protrusions or projections that could cause injury.
Knowing how the machine power is transmitted and having found hazardous parts, it is possible to provide guards that protect against contact or entanglement, being trapped between the machine and material, material in motion, being struck by ejected material, and the release of potential energy. Having completed this part of the assessment, it is time to obtain or design a guard that eliminates or minimizes the risk. Failing that, develop an administrative control or provide personal protective equipment that offers employees an equivalent protection.
There are a variety of machine guards and they fall into five classifications: fixed guards, interlocking guards, automatic guards, distance guards, and trip guards. Fixed guards prevent contact between any part of the body and moving parts. Interlocking guards prevent entry into the hazardous area by being wired or plumbed into the control power. Automatic guards move into place as equipment operates. Distance or proximity guards prevent access to a hazardous area with a barrier or fence. Finally, trip guards or presence sensing devices â€œsee or feelâ€? a worker getting into a hazardous situation. They include pressure sensitive mats, photo-eyes, and infrared beams.
Procedures must ensure that equipment is not started unless all guards are in place.
And therein is the mysterious part. After all the devastating injuries and deaths as well as OSHA citations and penalties, why do these incidents continue to occur? Every day, I hear about a worker injured because of a missing or inadequate machine guard. Why? It always goes back to procedures, training, and awareness, which are all part of our behaviors.
Pamela J. Cordier is executive director of the Pulp & Paper Safety Association.