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Machine Guarding to Reduce Hazards
OSHA Revises Guide to Protect Employees from Amputation

OSHA has issued a new guide on Safeguarding Equipment and Protecting Employees from Amputations, a revision to assist employers in providing a safe and healthful workplace for their employees.

This revised guide ties directly to OSHA’s National Emphasis Program on Amputations, released in October.
“Amputations are among the most severe and disabling workplace injuries that result in permanent disability. They are widespread and involve various activities and equipment,” said Assistant Secretary of Labor for OSHA, Edwin G. Foulke, Jr.

“These injuries result from the use and care of machines such as saws, presses, conveyors and bending, rolling or shaping machines as well as from powered and non-powered hand
tools, forklifts, doors, trash compactors and during materials handling activities. Our revised guide offers practical information for the small business employer to identify and manage common amputation hazards associated with the operation and care of machines.”

The revised OSHA guide identifies eight mechanical motions and eight hazardous actions that present possible amputation hazards. The guide also sets forth steps employers can take to reduce these hazards.
The material in Safeguarding Equipment and Protecting Employees from Amputations is appropriate for anyone responsible for the operation, servicing and care of machines or equipment — employers, employees, safety professionals and industrial hygienists. Topics covered in the latest document include hazard analysis, safeguarding machinery, awareness devices and hazardous energy (lockout/tagout).

This Instruction expands on the existing National Emphasis Program on Amputations. Major changes include:
. • The revised directive focuses on identifying industries and establishments associated with amputations rather than on equipment associated with amputations.
. • Appendix D of the revised directive lists some of the typical machinery and equipment associated with amputations.
. • The revised directive incorporates a comparison chart for the Standard Industrial Classiﬁcation (SIC) codes and the North American Industry Classiﬁcation System (NAICS) codes in Appendix B.
. • The revised targeting methodology is based on a combination of more current data from IMIS and BLS sources as explained in Appendix C.
. • The revised targeting methodology includes two additional standards that are generally recognized as being related to amputation hazards. The additional standards are §1910.147, The Control of Hazardous Energy (Lockout/Tagout) and §1910.219, Mechanical Power-transmission Apparatus.

Printed copies of OSHA’s revised guide are available by calling (202) 693¬1888, or by writing U.S. Department of Labor, OSHA Publications, P.O. Box 37535, Washington, D.C. 20013-7535. It is also available on OSHA’s Web site at www.osha.gov/pls/publications/pu-bindex.list.

Injury statistics compiled by OSHA indicate that nearly half of the injuries from mechanical power presses result in an amputation. Thus, to enhance the protection provided to all press operators, emphasis should be placed on ensuring the proper use of existing point-of-operation safeguards and the development of improved safeguards.

The National Institute for Occupational Safety and Health has concluded that despite OSHA standards, a signiﬁcant risk of injury to power press operators remains.

Operators are not always protected by the safeguarding provided because there are wide variations in hand speed among males, females, younger workers and older workers. In addition to variations in hand speed there are several reasons why existing safeguarding may not provide the desired protection, such as:
• On machines that stamp differently shaped parts, each of which needs a different guard, it may take more time to install the proper safeguarding than it takes to run the job.
• Operators sometimes defeat the purpose of safeguards by removing or overriding them for convenience or increased productivity.
• Safeguarding is not always adjusted properly. This may be a problem with pullout and restraint devices if workers with different hand sizes and arm lengths work on consecutive shifts at the same machine. In some cases, dual palm buttons may be located too close to the point of operation because use of the existing hand-speed constant leads to erroneous placement of the palm buttons. Also, two-hand controls or presence sensing devices may be improperly located after dies are changed.

The NIOSH recommendations presented below were compiled from generally accepted safety practices and research; they are intended to supplement existing OSHA standards. Implementation of these recommendations should be considered in any comprehensive safety program for the prevention of injuries among mechanical power press operators. NIOSH emphasizes that data from its studies demonstrate that hand speed may be an inappropriate measure on which to base a safety distance standard for operation of mechanical power presses.

It may be impractical to implement a single hand-speed constant which would protect all workers under all power press set-ups. Implementation of such a hand-speed standard would render dual palm buttons practically useless as a safeguarding device due to the long safety distances, which would result, says NIOSH.

Additional information pertaining to the design of safeguards for mechanical power press safety can be found in OSHA 1980, ANSI 1982, and Wilco Inc. 1976 and 1976a.
Foot-Controlled Power Presses
• Foot controls should be used with point-of-operation safeguards that cannot be easily bypassed or misadjusted.
• Interlocking safeguards should be considered so that the foot control is inoperable when the safeguards are not functioning.
• An ergonomically correct, sitting work position, if possible, is preferred over a standing position if a foot control is used.
• To reduce strain on the foot, a foot-rest should be provided near the pedal.
• Riding the pedal (keeping the foot on the pedal without actually depressing it) is hazardous, and standard operating procedures should note this unacceptable work practice.
• The rate at which presses are being cycled should be monitored periodically to ensure that operators are not working at a pace that leads to inadvertent pressing of the foot pedal.

the safeguarding provided because there are wide variations in hand speed among males, females, younger workers and older workers. In addition to variations in hand speed there are several reasons why existing safeguarding may not provide the desired protection, such as:
• On machines that stamp differently shaped parts, each of which needs a different guard, it may take more time to install the proper safeguarding than it takes to run the job.
• Operators sometimes defeat the purpose of safeguards by removing or overriding them for convenience or increased productivity.
• Safeguarding is not always adjusted properly. This may be a problem with pullout and restraint devices if workers with different hand sizes and arm lengths work on consecutive shifts at the same machine. In some cases, dual palm buttons may be located too close to the point of operation because use of the existing hand-speed constant leads to erroneous placement of the palm buttons. Also, two-hand controls or presence
sensing devices may be improperly located after dies are changed.
The NIOSH recommendations presented below were compiled from generally accepted safety practices and research; they are intended to supplement existing OSHA standards. Implementation of these recommendations should be considered in any comprehensive safety program for the prevention of injuries among mechanical power press operators. NIOSH emphasizes that data from its studies demonstrate that hand speed may be an inappropriate measure on which to base a safety distance standard for operation of mechanical power presses.
It may be impractical to implement a single hand-speed constant which would protect all workers under all power press set-ups. Implementation of such a hand-speed standard would render dual palm buttons practically useless as a safeguarding device due to the long safety distances, which would result, says NIOSH.
Additional information pertaining to the design of safeguards for mechanical power press safety can be found in OSHA 1980, ANSI 1982, and Wilco Inc. 1976 and 1976a.
Foot-Controlled Power Presses
• Foot controls should be used with point-of-operation safeguards that cannot be easily bypassed or misadjusted.
• Interlocking safeguards should be considered so that the foot control is inoperable when the safeguards are not functioning.
• An ergonomically correct, sitting work position, if possible, is preferred over a standing position if a foot control is used.
• To reduce strain on the foot, a foot-rest should be provided near the pedal.
• Riding the pedal (keeping the foot on the pedal without actually depressing it) is hazardous, and standard operating procedures should note this unacceptable work practice.
• The rate at which presses are being cycled should be monitored periodically to ensure that operators are not working at a pace that leads to inadvertent pressing of the foot pedal.

Power Presses Controlled with Dual Palm Buttons

• Because full-revolution clutches cannot be stopped once they are activated, they should only be used on presses with short downstrokes or fast cycling rates.

• To reduce musculoskeletal stress to the wrists, arms, and shoulders of press operators, ergonomic job design principles should be considered when locating and/or orienting dual palm buttons in relation to the point of operation.

• Caution must be exercised in evaluating each power press set-up and operation to ensure that an adequate safety distance is maintained at all times.

Employers should consider evaluating individual press operators to determine if they are exceeding the current OSHA hand-speed constant. If a worker is identified as being capable of exceeding the hand-speed constant, more positive means of point-of-operation safeguarding should be considered, such as fixed barrier guards.

Recommended Checklists for Safe Operation of Mechanical Power Presses

The checklists presented below are provided as an adjunct to the above recommendations to aid in maintaining safe use of foot and dual palm-button controls for mechanical power presses.

Checklist to be used when foot controls are used:

• Safeguards are in place that will prevent injury if the foot control is inadvertently depressed;

• A guard or cover is over the foot switch to prevent activation by fallen objects;

• The working posture is as non-fatiguing as possible. Seating is provided where possible;

• Presence-sensing devices, if used, are properly maintained and aligned to ensure that the sensing ﬁeld is effectively safeguarding the point of operation;

• Work rules have been established against riding the foot pedal;

• A check has been made to see if operators inadvertently push the foot switch because they are working at a high cycling rate

with the foot control;

• The brake monitor, if required, is operative;

• The foot control must be depressed and re-leased once before the press can be cycled again;

• Safeguarding devices and procedures are available for die set-up and maintenance to prevent or arrest an inadvertent downstroke of the ram; and

• The press is routinely and frequently inspected and properly maintained.

Checklist to be used when dual palm buttons are used:

• The palm buttons are installed to meet at least the OSHA minimum safety distance requirements. Greater distances are recommended based on the operator’s true hand speed;

• The palm buttons are installed to reduce undue operator fatigue;

• The palm buttons are protected against un-intended operation and are arranged so that the only probable means of operation is by both hands of a single worker, or by both hands of each operator where more than one operator is being protected by dual palm buttons;

• On presses with part-revolution clutches, the removal of a worker’s hand from any palm button during the downstroke of the ram quickly deactivates the clutch and applies the brake to stop ram motion;

• The brake monitor, if required, is operative;

• All palm buttons must be released before an interrupted stroke can be resumed or the press can be cycled again;

• The palm buttons are ﬁxed in a position so that only a set-up person, supervisor or safety engineer can move them;

• The position of the palm buttons is arranged to prevent any part of the body from entering the working zone of the press during the downstroke;

• The operation of the press is monitored frequently to ensure that operators are not bypassing or defeating the safety features of the dual palm buttons;

• Safeguarding devices and procedures are available for die set-up and maintenance to prevent or arrest an inadvertent downstroke of the ram;

• Presence-sensing devices, if used, are properly maintained and aligned to ensure that the sensing ﬁeld is effectively safeguarding the point of operation; and The press is routinely and frequently inspected and properly maintained. FSM