osha guide

Safeguarding Equipment andProtecting Employees from

Amputations

www.osha.gov

Small Business Safety andHealth Management Series

OSHA 3170-02R 2007

Employers are responsible for providing a safe andhealthful workplace for their employees. OSHAsrole is to assure the safety and health of Americasemployees by setting and enforcing standards; pro-viding training, outreach, and education; establish-ing partnerships; and encouraging continual im-provement in workplace safety and health.

This publication is in the public domain and may bereproduced, fully or partially, without permission.Source credit is requested, but not required.

This information is available to sensory impairedindividuals upon request. Voice phone: (202) 693-1999; teletypewriter (TTY) number: (877) 889-5627.

Edwin G. Foulke, Jr.Assistant Secretary of Labor forOccupational Safety and Health

Safeguarding Equipmentand Protecting Employees

from Amputations

Occupational Safety and Health AdministrationU.S. Department of Labor

OSHA 3170-02R 2007

2Occupational Safety and Health Administration

This OSHA publication is not a standard or regulation, and it creates no new legal obligations. Thepublication is advisory in nature, informational in content, and is intended to assist employers inproviding a safe and healthful workplace. The Occupational Safety and Health Act requires employersto comply with hazard-specific safety and health standards. In addition, pursuant to Section 5(a)(1),the General Duty Clause of the Act, employers must provide their employees with a workplace freefrom recognized hazards likely to cause death or serious physical harm. Employers can be cited forviolating the General Duty Clause if there is a recognized hazard and they do not take reasonablesteps to prevent or abate the hazard. However, failure to implement these recommendations is not,in itself, a violation of the General Duty Clause. Citations can only be based on standards, regula-tions, and the General Duty Clause.

ContentsIntroduction 5

OSHA Standards 5National Consensus Standards 6

Recognizing Amputation Hazards 7Hazardous Mechanical Components 7Hazardous Mechanical Motions 7Hazardous Activities 9Hazard Analysis 9

Controlling Amputation Hazards 9Safeguarding Machinery 9Primary Safeguarding Methods 10Guards 10Safeguarding Devices 13Secondary Safeguarding Methods 16Probe Detection and Safety Edge Devices 16Awareness Devices 17Safeguarding Methods 17Safe Work Procedures 18Complementary Equipment 18Administrative Issues 19Inspection and Maintenance 19Lockout/Tagout 20

Specific Machine Hazards andSafeguarding Methods 20

Hazards of Mechanical Power Presses 20Safeguarding Mechanical Power Presses 22Other Controls for Mechanical Power Press

Servicing and Maintenance 23Training 24Additional Requirements 24Power Press Brakes 25Hazards of Power Press Brakes 25Safeguarding Power Press Brakes 25Other Controls for Power Press Brakes 26 Hazards of Conveyors 26Safeguarding Conveyors 28Other Controls for Conveyors 29Hazards of Printing Presses 30Safeguarding Printing Presses 31Other Controls for Printing Presses 32 Hazards of Roll-Forming and

Roll-Bending Machines 33

Safeguarding Roll-Forming and Roll-Bending Machines 33

Other Controls for Roll-Forming and Roll-Bending Machines 34

Hazards of Shearing Machines 35Safeguarding Shearing Machines 36Other Controls for Shearing Machines 36Hazards of Food Slicers 37 Safeguarding and Other Controls for

Food Slicers 38Hazards of Meat Grinders 38Safeguarding and Other Controls for

Meat Grinders 39Hazards of Meat-Cutting Band Saws 39Safeguarding and Other Controls for

Meat-Cutting Band Saws 40Hazards of Drill Presses 41Safeguarding and Other Controls for

Drill Presses 42Hazards of Milling Machines 43Safeguarding and Other Controls for

Milling Machines 44Hazards of Grinding Machines 45Safeguarding and Other Controls for

Grinding Machines 46Hazards of Slitters 46Safeguarding and Other Controls for

Slitters 47

OSHA Assistance 49

References 51

Appendix A.Amputation Hazards Not Covered in this Guide 53

Appendix B.Amputation Hazards Associated with Other Equipment and Activities 54

Appendix C.OSHA Regional Offices 55

S A F E G U A R D I N G E Q U I P M E N T A N D P R O T E C T I N G E M P L O Y E E S F R O M A M P U T A T I O N S 3

4Occupational Safety and Health Administration

List of TablesTable 1. Commonly Used Machine Guards 12Table 2. Types of Safeguarding Devices 13

List of FiguresFigure 1. Rotating Motion 7Figure 2. Reciprocating Motion 7Figure 3. Transversing Motion 7Figure 4. Cutting Action 7Figure 5. Punching Action 8Figure 6. Shearing Action 8Figure 7. Bending Action 8Figure 8. In-Running Nip Points 8Figure 9. Fixed Guard on a Power Press 11Figure 10. Power Press with an Adjustable

Barrier Guard 11Figure 11. Self-Adjusting Guard on a

Radial Saw 11Figure 12. Interlocked Guard on a Roll

Make-up Machine 11Figure 13. Pullback Device on a Power Press 13Figure 14. Restraint Device on a Power Press 16Figure 15. Presence-Sensing Device on a

Power Press 16Figure 16. Two-Hand Control 16Figure 17. Power Press with a Gate 16Figure 18. Power Press with a Plunger Feed 17Figure 19. Shuttle Ejection Mechanism 18Figure 20. Safety Tripod on a Rubber Mill 18Figure 21. Typical Hand-Feeding Tools 19

Figure 22. Properly Guarded Foot Control 19Figure 23. Part Revolution Mechanical Power

Press with a Two-Hand Control 21Figure 24. Hand-Feeding Tools Used in

Conjunction with Pullbacks on a Power Press 23

Figure 25. Power Press Brake Bending Metal 25Figure 26. Two-Person Power Press Brake

Operation with Pullbacks 26Figure 27. Belt Conveyor 27 Figure 28. Screw Conveyor 27Figure 29. Chain Driven Live Roller Conveyor 27Figure 30. Slat Conveyor 28Figure 31. Roll-to-Roll Offset Printing Press 31Figure 32. Sheet-Fed Offset Printing Press 31Figure 33. Roll-Forming Machine 33Figure 34. In-Feed Area of a Roll-Forming

Machine 33Figure 35. Hydraulic Alligator Shear 35Figure 36. Power Squaring Shear 35Figure 37. Meat Slicer 37Figure 38. Stainless Steel Meat Grinder 38Figure 39. Stainless Steel Meat-Cutting

Band Saw 40Figure 40. Drill Press with a Transparent

Drill Shield 41Figure 41. Bed Mill 43Figure 42. Horizontal Surface Grinder 45Figure 43. Paper Slitter 47

IntroductionAmputations are among the most severe and dis-abling workplace injuries that often result in perma-nent disability. They are widespread and involvevarious activities and equipment. (The U.S. Bureauof Labor Statistics 2005 annual survey data indicat-ed that there were 8,450 non-fatal amputation cases involving days away from work for all privateindustry. Approximately forty-four percent (44%) ofall workplace amputations occurred in the manu-facturing sector and the rest occurred across theconstruction, agriculture, wholesale and retail trade,and service industries.) These injuries result fromthe use and care of machines such as saws, press-es, conveyors, and bending, rolling or shapingmachines as well as from powered and non-pow-ered hand tools, forklifts, doors, trash compactorsand during materials handling activities.

Anyone responsible for the operation, servicing,and maintenance (also known as use and care) ofmachines (which, for purposes of this publicationincludes equipment) employers, employees,safety professionals, and industrial hygienistsshould read this publication. Primary safeguarding,as used in this publication, includes control meth-ods that protect (e.g., prevent employee contactwith hazardous machine areas) employees frommachine hazards through effective machine guard-ing techniques. In addition, a hazardous energycontrol (lockout/tagout) program needs to comple-ment machine safeguarding methods in order toprotect employees during potentially hazardousservicing and maintenance work activities.

This guide can help you, the small businessemployer, identify and manage common amputa-tion hazards associated with the operation and careof machines. The first two sections of the document,Recognizing Amputation Hazards and ControllingAmputation Hazards, look at sources of amputa-tions and how to safeguard machinery and controlemployee exposure to hazardous energy (lockout/tagout) during machine servicing and maintenanceactivities. The section on Specific MachineryHazards and Safeguarding Methods identifies thehazards and various control methods for machineryassociated with workplace amputations, such as:mechanical power presses, press brakes, convey-ors, printing presses, roll-forming and roll-bendingmachines, shears, food slicers, meat grinders, meat-cutting band saws, drill presses, milling machines,grinding machines, and slitting machines.

The information in this booklet does not specif-ically address amputation hazards on all types of

machinery in general industry, construction, mar-itime and agricultural operations; however, manyof the described safeguarding techniques may beused to prevent other amputation injuries. Ad-ditionally, while this manual concentrates attentionon concepts and techniques for safeguardingmechanical motion, machines obviously present avariety of other types of energy hazards that cannotbe ignored. For example, pressure system failurecould cause fires and explosions. Machine electri-cal sources also pose electrical hazards that areaddressed by other OSHA standards, such as theelectrical standards contained in Subpart S. Fulldiscussion of these matters is beyond the scope ofthis publication. For compliance assistance purpos-es, references and the appendices are provided onapplicable OSHA standards, additional informationsources, and ways you may obtain OSHA assistance.

OSHA StandardsAlthough this guide recommends ways to safeguardand lockout/tagout energy sources associated withmachinery hazards, there are legal requirements inOSHA standards that you need to know about andcomply with. The following OSHA standards are afew of the regulations that protect employees fromamputation hazards.

Machinery and Machine Guarding:29 CFR Part 1910, Subpart O

1910.211 Definitions 1910.212 General requirements for all

machines 1910.213 Woodworking machinery require-

ments 1910.215 Abrasive wheel machinery 1910.216 Mills and calenders in the rubber

and plastics industries 1910.217 Mechanical power presses 1910.218 Forging machines 1910.219 Mechanical power-transmission

apparatus

Control of Hazardous Energy (Lockout/Tagout):29 CFR 1910.147

Hand and Power Tools:29 CFR Part 1926, Subpart I

1926.300 General requirements 1926.303 Abrasive wheels and tools 1926.307 Mechanical power-transmission

apparatus

Conveyors:29 CFR 1926.555


Concrete and Masonry Construction 29 CFR Part 1926, Subpart Q 1926.702 Requirements for equipment and

tools

Consult these standards directly to ensure fullcompliance with the provisions as this publicationis not a substitute for the standards. States withOSHA-approved plans have at least equivalentstandards. For detailed information about machineguarding and lockout/tagout, see the followingresources: Machine Guarding Safety and Health Topics

Page (http://www.osha.gov/SLTC/machineguarding/index.html)

Machine Guarding eTool (http://www.osha.gov/SLTC/etools/machineguarding/index.html)

OSHA Publication 3067, Concepts and Techniquesof Machine Safeguarding (http://www.osha.gov/Publications/Mach_Safeguarding/toc.html)

OSHA Directive STD 01-05-019 [STD 1-7.3],Control of Hazardous Energy (Lockout/Tagout)Inspection Procedures and Interpretive Guidance

Control of Hazardous Energy (Lockout/Tagout)Safety and Health Topics Page (http://www.osha.gov/SLTC/controlhazardousenergy/index.html)

OSHAs Lockout Tagout Interactive TrainingProgram (http://www.osha.gov/dts/osta/ lototraining/index.htm)

OSHA Publication 3120, Control of HazardousEnergy (Lockout/Tagout)

OSHA standards, directives, publications, and other resources are available online atwww.osha.gov.

National Consensus StandardsOSHA recognizes the valuable contributions ofnational consensus standards and these voluntarystandards may be used as guidance and recognitionof industry accepted practices. For example, theAmerican National Standards Institute (ANSI) pub-lishes numerous voluntary national consensus stan-dards on the safe care and use of specific machinery.These consensus standards provide you with usefulguidance on how to protect your em-ployees frommachine amputation hazards and the controlmethods described may assist you in complyingwith OSHA performance-based standards.

Furthermore, OSHA encourages employers toabide by the more current industry consensus stan-dards since those standards are more likely to beabreast of the state of the art than an applicableOSHA standard may be. However, when a consen-sus standard addresses safety considerations, OSHA

may determine that the safety practices describedby that consensus standard are less protective thanthe requirement(s) set forth by the pertinent OSHAregulations. OSHA enforcement policy regardingthe use of consensus standards is that a violationof an OSHA standard may be deemed de minimisin nature if the employer complies with a consen-sus standard (that is not incorporated by reference)rather than the OSHA standard in effect and if theemployers action clearly provides equal or greateremployee protection. (Such de minimis violationsrequire no corrective action and result in no penalty.)

For example, the OSHA point-of-operationguarding provisions, contained in paragraph1910.212(a)(3), require the guarding device tobein conformance with any appropriate standardsthereof, or in the absence of applicable specificstandards, shall be so designed and constructed asto prevent the operator from having any part of hisbody in the danger zone during the operating cycle.The terms applicable standards or appropriate stan-dards, as used in the context of 29 CFR 1910.212,are references to those private consensus stan-dards that were adopted (source standards) orincorporated by reference in the OSHA standards.

In some instances, a specific national consensusstandard (that is not incorporated by reference or asource standard), such as an ANSI standard for aparticular machine, may be used for guidance pur-poses to assist employers in preventing an opera-tor from having any body part in the machine dan-ger zone during the operating cycle. Also, OSHAmay, in appropriate cases, use these consensusstandards as evidence that machine hazards are rec-ognized and that there are feasible means of cor-recting the hazard. On the other hand, some nation-al consensus standards may sanction practices thatprovide less employee protection than that providedby compliance with the relevant OSHA provisions.In these cases, compliance with the specific consen-sus standard provision would not constitute compli-ance with the relevant OSHA requirement.

Under the Fair Labor Standards Act (FLSA), theSecretary of Labor has designated certain non-farm jobs as particularly hazardous for employ-ees younger than 18. Generally, these employ-ees are prohibited from operating: Band saws Circular saws Guillotine

shears Punching and shearing machines Meatpacking or meat-processing machines Certain power-driven machines: Paper products

machines, Woodworking machines, Metalforming machines, and Meat slicers.

6

Occupational Safety and Health Administration

Recognizing AmputationHazardsTo prevent employee amputations, you and youremployees must first be able to recognize the con-tributing factors, such as the hazardous energy associ-ated with your machinery and the specific employeeactivities performed with the mechanical operation.Understanding the mechanical components ofmachinery, the hazardous mechanical motion thatoccurs at or near these components and specificemployee activities performed in conjunction withmachinery operation will help employees avoid injury.

Hazardous Mechanical Components Three types of mechanical components presentamputation hazards:

Point of Operation is the area of the machinewhere the machine performs work i.e., mechani-cal actions that occur at the point of operation,such as cutting, shaping, boring, and forming.

Power-Transmission Apparatus is all componentsof the mechanical system that transmit energy,such as flywheels, pulleys, belts, chains, couplings,connecting rods, spindles, cams, and gears.

Other Moving Parts are the parts of the machinethat move while the machine is operating, suchas reciprocating, rotating, and transverse mov-ing parts as well as lead mechanisms and auxil-iary parts of the machine.

Hazardous Mechanical MotionsA wide variety of mechanical motion is potentiallyhazardous. Here are the basic types of hazardousmechanical motions:

Rotating Motion (Figure 1) is circular motion suchas action generated by rotating collars, couplings,cams, clutches, flywheels, shaft ends, and spin-dles that may grip clothing or otherwise force abody part into a dangerous location. Even smoothsurfaced rotating machine parts can be hazardous.Projections such as screws or burrs on the rotat-ing part increase the hazard potential.

Figure 1 Rotating Motion

Reciprocating Motion (Figure 2) is back-and-forthor up-and-down motion that may strike or entrapan employee between a moving part and a fixedobject.

Figure 2 Reciprocating Motion

Transversing Motion (Figure 3) is motion in astraight, continuous line that may strike or catchan employee in a pinch or shear point created bythe moving part and a fixed object.

Figure 3 Transversing Motion

Cutting Action (Figure 4) is the action that cutsmaterial and the associated machine motion maybe rotating, reciprocating, or transverse.

Figure 4 Cutting Action


Table

Bed (stationary)

Punching Action (Figure 5) begins when powercauses the machine to hit a slide (ram) to stampor blank metal or other material. The hazardoccurs at the point of operation where theemployee typically inserts, holds, or withdrawsthe stock by hand.

Figure 5 Punching Action

Shearing Action (Figure 6) involves applyingpower to a slide or knife in order to trim or shearmetal or other materials. The hazard occurs at thepoint of operation where the employee typicallyinserts, holds, or withdraws the stock by hand.

Figure 6 Shearing Action

Bending Action (Figure 7) is power applied to aslide to draw or stamp metal or other materials ina bending motion. The hazard occurs at the pointof operation where the employee typically inserts,holds, or withdraws the stock by hand.

Figure 7 Bending Action

In-Running Nip Points (Figure 8), also known aspinch points, develop when two parts movetogether and at least one moves in rotary or circu-lar motion. In-running nip points occur whenevermachine parts move toward each other or whenone part moves past a stationary object. Typicalnip points include gears, rollers, belt drives, andpulleys.

Figure 8 In-Running Nip Points

8


Blade

Stock

Punch

Stock

Die

Nip Point

NipPoint

Typical Nip Point

Nip Point

Nip Point

Nip Point

Hazardous Activities Employees operating and caring for machineryperform various activities that present potentialamputation hazards.

Machine set-up/threading/preparation,*Machine inspection,*Normal production operations,Clearing jams,*Machine adjustments,*Cleaning of machine,*Lubricating of machine parts,* andScheduled and unscheduled maintenance.*

* These activities are servicing and/or mainte-nance activities.

Hazard AnalysisYou can help prevent workplace amputations bylooking at your workplace operations and identify-ing the hazards associated with the use and care ofthe machine. A hazard analysis is a technique thatfocuses on the relationship between the employee,the task, the tools, and the environment. Whenevaluating work activities for potential amputationhazards, you need to consider the entire machineoperation production process, the machine modesof operation, individual activities associated withthe operation, servicing and maintenance of themachine, and the potential for injury to employees.

The results from the analysis may then be usedas a basis to design machine safeguarding and anoverall energy control (lockout/tagout) program.This is likely to result in fewer employee amputa-tions; safer, more effective work methods; reducedworkers compensation costs; and increased em-ployee productivity and morale.

Controlling AmputationHazardsSafeguarding is essential for protecting employeesfrom needless and preventable injury. A good ruleto remember is:

Any machine part, function, or process that maycause injury must be safeguarded.

In this booklet, the term primary safeguardingmethods refers to machine guarding techniquesthat are intended to prevent or greatly reduce thechance that an employee will have an amputationinjury. Refer to the OSHA general industry (e.g.,Subpart O) and construction (e.g., Subparts I andN) standards for specific guarding requirements.Many of these standards address preventive meth-ods (such as using barrier guards or two-hand trip-ping devices) as primary control measures; whileother OSHA standards allow guarding techniques(such as a self-adjustable table saw guard) thatreduce the likelihood of injury. Other less protectivesafeguarding methods (such as safe work methods)that do not satisfactorily protect employees fromthe machine hazard areas are considered second-ary control methods.

Machine safeguarding must be supplementedby an effective energy control (lockout/tagout)program that ensures that employees are protectedfrom hazardous energy sources during machineservicing and maintenance work activities.Lockout/tagout plays an essential role in the pre-vention and control of workplace amputations. Interms of controlling amputation hazards, employ-ees are protected from hazardous machine workactivities either by: 1) effective machine safeguard-ing, or 2) lockout/tagout where safeguards are ren-dered ineffective or do not protect employees fromhazardous energy during servicing and mainte-nance operations.

Additionally, there are some servicing activities,such as lubricating, cleaning, releasing jams andmaking machine adjustments that are minor innature and are performed during normal produc-tion operations. It is not necessary to lockout/tagout a machine if the activity is routine, repetitiveand integral to the production operation providedthat you use an alternative control method thataffords effective protection from the machineshazardous energy sources.

Safeguarding MachineryThe employer is responsible for safeguardingmachines and should consider this need when pur-chasing machinery. Almost all new machinery is


available with safeguards installed by the manufac-turer, but used equipment may not be.

If machinery has no safeguards, you may beable to purchase safeguards from the originalmachine manufacturer or from an after-marketmanufacturer. You can also build and install thesafeguards in-house. Safeguarding equipmentshould be designed and installed only by technical-ly qualified professionals. If possible, the originalequipment manufacturer should review the safe-guard design to ensure that it will protect employ-ees without interfering with the operation of themachine or creating additional hazards.

Regardless of the source of safeguards, theguards and devices used need to be compatiblewith a machines operation and designed to ensuresafe operator use. The type of operation, size, andshape of stock, method of feeding, physical layoutof the work area, and production requirements allaffect the selection of safeguards. Also, safeguardsshould be designed with the machine operator inmind as a guarding method that interferes with theoperation of the machine may cause employees tooverride them. To ensure effective and safe operatoruse, guards and devices should suit the operation.

The Performance Criteria for Safeguarding[ANSI B11.19-2003] national consensus standardprovides valuable guidance as the standardaddresses the design, construction, installation,operation and maintenance of the safeguardingused to protect employees from machine hazards.The following safeguarding method descriptionsare, in part, structured like and, in many ways aresimilar to this national consensus standard.

The Performance Criteria for Safeguarding [ANSIB11.19-2003] defines safeguarding as the protec-tion of personnel from hazards by the use ofguards, safeguarding devices awareness devices,safeguarding methods, or safe work procedures.The following ANSI B11.19 definitions describethe various types of safeguarding:

Guard: A barrier that prevents exposure to anidentified hazard.

Safeguarding device: A device that detects orprevents inadvertent access to a hazard.

NOTE: The 1990 ANSI B11.19 term Safeguardingdevice was modified to Safeguarding (Protective)Device in the revised 2003 ANSI standard and thenew term includes a detection component. De-vices that detect, but do not prevent employee

exposure to machine hazards are not consideredby OSHA to be primary safeguarding methods.

Awareness device: A barrier, signal or sign thatwarns individuals of an impending, approachingor present hazard.

Safeguarding method: Safeguarding implement-ed to protect individuals from hazards by thephysical arrangement of distance, holding, open-ings, or positioning of the machine or machineproduction system to ensure that the operatorcannot reach the hazard.

Safe work procedures: Formal written instruc-tions developed by the user which describe howa task is to be performed.

Primary Safeguarding MethodsTwo primary methods are used to safeguardmachines: guards and some types of safeguardingdevices. Guards provide physical barriers that pre-vent access to danger areas. Safeguarding deviceseither prevent or detect operator contact with thepoint of operation or stop potentially hazardousmachine motion if any part of an individuals bodyis within the hazardous portion of the machine.Both types of safeguards need to be properlydesigned, constructed, installed, used and main-tained in good operating condition to ensureemployee protection.

Criteria for Machine Safeguarding

Prevents employee contact with the hazardarea during machine operation.

Avoids creating additional hazards. Is secure, tamper-resistant, and durable. Avoids interfering with normal operation of

the machine. Allows for safe lubrication and maintenance.

GuardsGuards usually are preferable to other controlmethods because they are physical barriers thatenclose dangerous machine parts and preventemployee contact with them. To be effective,guards must be strong and fastened by any securemethod that prevents the guard from being inad-vertently dislodged or removed. Guards typicallyare designed with screws, bolts and lock fastenersand usually a tool is necessary to unfasten and

1 0


remove them. Generally, guards are designed notto obstruct the operators view or to preventemployees from doing a job.

In some cases, guarding may be used as analternative to lockout/tagout because employeescan safely service or maintain machines with aguard in place. For example, polycarbonate andwire-mesh guards provide greater visibility and canbe used to allow maintenance employees to safelyobserve system components. In other instances,employees may safely access machine areas, with-out locking or tagging out, to perform maintenancework (such as machine cleaning or oiling tasks)because the hazardous machine componentsremain effectively guarded.

Guards must not create additional hazards suchas pinch points or shear points between guardsand other machine parts. Guard openings shouldbe small enough to prevent employees fromaccessing danger areas. (See Table 1 and Figures9 through 12 for commonly used machine guards.)

Figure 9 Fixed Guard on a Power Press

Figure 10 Power Press with an Adjustable Barrier Guard

S A F E G U A R D I N G E Q U I P M E N T A N D P R O T E C T I N G E M P L O Y E E S F R O M A M P U T A T I O N S 1 1

Figure 11 Self-Adjusting Guard on a Radial Saw

Figure 12 Interlocked Guard on a Roll Make-up Machine

Transparent Insert

EnteringStock

ExitingStock

Bar

Guard

Handle

Anti-KickbackDevice

Blade

Switch

Guard

1 2


Type

Fixed

Adjustable

Self-Adjusting

InterlockingBarrierGuards

Method ofSafeguarding

Barrier that allows for stock feeding but does notpermit operator to reachthe danger area.

Barrier that adjusts for a variety of productionoperations.

Barrier that moves according to the size of thestock entering point ofoperation. Guard is in placewhen machine is at restand pushes away whenstock enters the point ofoperation.

Shuts off or disengagespower and preventsmachine start-up whenguard is open. Shouldallow for inching ofmachine.

Advantages

Can be constructed to suitmany applications.

Permanently encloses the point of operation orhazard area.

Provides protectionagainst machine repeat.

Allows simple, in-plantconstruction, with mini-mal maintenance.

Can be constructed tosuit many applications.

Can be adjusted to admitvarying stock sizes.

Off-the-shelf guards areoften commercially avail-able.

Allows access for someminor servicing work, inaccordance with the lock-out/tagout exception,without time-consumingremoval of fixed guards.

Limitations

Sometimes not practicalfor changing productionruns involving differentsize stock or feedingmethods.

Machine adjustment andrepair often require guardremoval.

Other means of protectingmaintenance personneloften required(lockout/tagout).

May require frequentmaintenance or adjustment.

Operator may make guard ineffective.

Does not provide maximum protection.

May require frequentmaintenance and adjustment.

May require periodicmaintenance or adjust-ment.

Movable sections cannotbe used for manual feed-ing.

Some designs may beeasy to defeat.

Interlock control circuitrymay not be used for allmaintenance and servic-ing work.

Table 1. Commonly Used Machine Guards

Types of Machine Guards

Safeguarding Devices Safeguarding devices are controls or attachmentsthat, when properly designed, applied and used,usually prevent inadvertent access by employees tohazardous machine areas by:

Preventing hazardous machine component oper-ation if your hand or body part is inadvertentlyplaced in the danger area;

Restraining or withdrawing your hands from thedanger area during machine operation;

Requiring the use of both of your hands onmachine controls (or the use of one hand if thecontrol is mounted at a safe distance from thedanger area) that are mounted at a predeter-mined safety distance; or

Providing a barrier which is synchronized withthe operating cycle in order to prevent entry tothe danger area during the hazardous part of thecycle.

These types of engineering controls, whicheither prevent the start of or stop hazardousmotion, may be used in place of guards or assupplemental control measures when guards alonedo not adequately enclose the hazard. In order forthese safeguarding devices to accomplish thisrequirement, they must be properly designed andinstalled at a predetermined safe distance from themachines danger area. Other safeguarding devices(probe detection and safety edge devices) thatmerely detect, instead of prevent, inadvertent

access to a hazard are not considered primary safe-guards. (See Table 2 and Figures 13 through 17 forthe types of safeguarding devices.)

Figure 13 Pullback Device on a Power Press


PullbackMechanism

PullbackStraps

Wristbands

Type

PullbackDevices


Cords connected to operators wrists and linked mechanically to the machine automaticallywithdraw the hands fromthe point of operation during the machine cycle.

Advantages

Allows the hands to enterthe point of operation forfeeding and removal.

Provides protection evenin the event of mechani-cal repeat.

Limitations

Close supervision ensuresproper use and adjust-ment. Must be inspectedprior to each operatorchange or machine set-up.

Limits operators move-ment and may obstructtheir work space.

Operator may easily makedevice ineffective by notadjusting the device properly.

Table 2. Types of Safeguarding Devices


1 4


Type

RestraintDevices

Presence-SensingDevices

Presence-SensingMats


Wrists are connected bycords and secured to afixed anchor point whichlimit operators hands fromreaching the point of oper-ation at any time.

Interlock into the machinescontrol system to stopoperation when the sens-ing field (photoelectric,radio frequency, or electro-magnetic) is disturbed.

Interlock into machinescontrol system to stopoperation when a predeter-mined weight is applied tothe mat. A manual resetswitch must be located out-side the protected zone.

Advantages

Simple, few moving parts; requires little maintenance.

Operator cannot reachinto the danger area.

Little risk of mechanicalfailure; provides protec-tion even in the event ofmechanical repeat.

Adjusts to fit differentstock sizes.

Allows access to load and unload the machine.

Allows access to theguarded area for maintenance and set-up activities.

Full visibility and accessto the work area.

Install as a perimeterguard or over an entirearea.

Configure for many applications.

Limitations

Close supervision re-quired to ensure properuse and adjustment.Must be inspected priorto each operator changeor machine set-up.

Operator must use handtools to enter the point ofoperation.

Limits the movement ofthe operator; mayobstruct work spacearound operator.

Operator may easily makedevice ineffective by dis-connecting the device.

Restricted to machinesthat stop operating cyclebefore operator can reachinto danger area (e.g.,machines with partial revolution clutches orhydraulic machines).

Must be carefully main-tained and adjusted.

Does not protect operator in the event of a mechanical failure.

Operator may makedevice ineffective.

Restricted to machinesthat stop operating cyclebefore operator can reachinto danger area (e.g.,machines with part-revolution clutches orhydraulic machines).

Some chemicals candegrade the mats.

Does not protect operator during mechanical failures.

Table 2. Types of Safeguarding Devices (continued)



Type

Two-HandControl

Two-Hand Trip

Type AGate(move-able barrier)

Type BGate(move-able barrier)


Requires concurrent andcontinued use of bothhands, preventing themfrom entering the dangerarea.

Requires concurrent use ofboth hands, prevents themfrom being in danger areawhen machine cycle starts.

Applicable to mechanicalpower presses. Providesbarrier between dangerarea and operator (or otheremployees) until comple-tion of machine cycle.

Applicable to mechanicalpower presses and pressbrakes. Provides a barrierbetween danger area andoperator (or other employ-ees) during the down-stroke.

Advantages

Operators hands are at a predetermined safetydistance.

Operators hands are freeto pick up new parts aftercompletion of first part ofcycle.

Operators hands are at a predetermined safetydistance.

Can be adapted to multiple operations.

No obstruction to handfeeding.

Prevents operator fromreaching into danger areaduring machine cycle.

Provides protection frommachine repeat.

May increase productionby allowing the operatorto remove and feed thepress on the upstroke.

Limitations

Requires a partial cyclemachine with a brake and anti-repeat feature.

Operator may makedevices without anti-tiedown ineffective.

Protects the operator only.

Operator may makedevices without anti-tiedown ineffective.

Protects the operatoronly.

Sometimes impracticalbecause distance require-ments may reduce pro-duction below acceptablelevel.

May require adjustmentwith tooling changes.

Requires anti-repeat feature.

May require frequentinspection and regularmaintenance.

May interfere with opera-tors ability to see work.

Can only be used onmachines with a part-revolution clutch orhydraulic machines.

May require frequentinspection and regularmaintenance.

May interfere with theoperators ability to seework.

Table 2. Types of Safeguarding Devices (continued)


Figure 17 Power Press with a Gate

Secondary Safeguarding Methods Other safeguarding methods, such as those describedin the Performance Criteria for Safeguarding (ANSIB11.19-2003), may also provide employees withsome protection from machine hazards. Detectionsafeguarding devices, awareness devices, safe-guarding methods and safe work procedures aredescribed in this section. These methods provide alesser degree of employee protection than the pri-mary safeguarding methods and they are consid-ered secondary control measures as they do notprevent employees from placing or having any partof their bodies in the hazardous machine areas.

Secondary safeguarding methods are accept-able only when guards or safeguarding devices(that prevent you from being exposed to machinehazards) cannot be installed due to reasons ofinfeasibility. Where it is feasible to use primarysafeguarding methods, secondary safeguardingmethods may supplement these primary controlmeasures; however, these secondary safeguardingmethods must not be used in place of primary safe-guarding methods.

Probe Detection and Safety Edge DevicesA probe detection device (sometimes referred to asa ring guard) detects the presence or absence of apersons hand or finger by encircling all or part ofthe machine hazard area. The ring guard makesyou aware of your hands entry into a hazardousarea and usually stops or prevents a hazardousmachine cycle or stroke, thereby reducing the likeli-hood of injuring yourself in the point of operation.These types of detection devices are commonlyused on spot welders, riveters, staplers and stack-

Figure 14 Restraint Device on a Power Press

Figure 15 Presence-Sensing Device on a Power Press

Figure 16 Two-Hand Control

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Emergency Stop

Press Bed

ControlBox

Light Curtain

GuardedFoot Control

Key Selector Capableof Being Supervised

Gate

Light Indicator

Emergency StopTop Stop

Safe Distance SafeguardingSafeguarding by safe distance (by location) mayinvolve an operator holding and supporting a work-piece with both hands at a predetermined mini-mum safe distance or, if both hands cannot be usedto hold the work-piece at a distance so that theoperator cannot reach the hazard with the freehand. For example, the feeding process itself cancreate a distance safeguard if the operators main-tain a safe distance between their hands and thepoint of operation. Additionally, where materialposition gauges are used, they need to be of suffi-cient height and size to prevent slipping of thematerial past the gauges.

Another example of a safe distance safeguard-ing method is the use of gravity feed methods thatreduce or eliminate employee exposure to machinehazards as the part slides down a chute into thepoint of operation. Automatic and semiautomaticfeeding and ejection methods can also protect theemployee by minimizing or eliminating employeeexposure with potentially hazardous machinerycomponents. An employee places the part in amagazine which is then fed into the point of opera-tion. Automatic and semiautomatic ejection methodsinclude pneumatic (jet of air), magnetic, mechanical(such as an arm), or vacuum. Figures 18 and 19illustrate different types of automatic feeding andejecting methods.

Figure 18 Power Press with a Plunger Feed


ers because primary safeguarding methods are notpossible. However, probe detection devices do notprevent inadvertent access to the point-of-operationdanger area; rather, they serve as a warning mech-anism and may prevent the initiation of or stop themachine cycle if an employees hand or finger(s) istoo close to the hazard area.

A safety edge device (sometimes called a bumpswitch) is another type of safeguard that detects thepresence of an employee when they are in contactwith the devices sensing edge. A safety edgedevice protects employees by initiating a stop com-mand when the sensing surface detects the pres-ence of a person; however, they do not usually,when used by themselves, prevent inadvertentaccess to machine danger areas. Therefore, addi-tional guarding or safeguarding devices must beprovided to prevent employee exposure to amachine hazard.

Awareness Devices Awareness devices warn employees of an impend-ing, approaching or present hazard. The first typeis an awareness barrier which allows access tomachine danger areas, but it is designed to contactthe employee, creating an awareness that he or sheis close to the danger point. Awareness signals,through the use of recognizable audible or visualsignals, are other devices that alert employees toan approaching or present hazard. Lastly, aware-ness signs are used to notify employees of thenature of the hazard and to provide instructionsand training information. OSHA standard 1910.145provides design, application, and use specificationsfor accident prevention (danger, caution, safetyinstruction) signs and (danger, caution, warning)tags.

Safeguarding Methods Safeguarding methods protect employees fromhazards by the physical arrangement of distance,holding, openings or the positioning of themachine components to ensure that the operatorcannot reach the hazard. Some safeguarding workmethods include safe distance safeguarding, safeholding safeguarding and safe opening safeguard-ing. Requirements for these secondary controlmeasures may be found in ANSI B11.19-2003.Proper training and supervision are essential toensure that these secondary safeguarding methodsare being used properly. Safeguarding work meth-ods may require the use of awareness devices,including the use of accident prevention signs wherethere is a need for warning or safety instruction.

Plunger PlungerHandle

Point ofOperationGuard

Nest

Figure 19 Shuttle Ejection Mechanism

Safe Holding Safeguarding (Safe Work-PieceSafeguarding)Operators hands are maintained away from thehazardous portion of the machine cycle by requir-ing that both hands are used to hold or support thework-piece, or by requiring that one hand holds thework-piece while the other hand operates themachine. For instance, if the stock is several feet longand only one end of the stock is being worked on,the operator may be able to hold the opposite endwhile performing the work. The operators bodyparts are out of the machine hazard area during thehazardous portion of the machine cycle. However,this work method only protects the operator.

Safe Opening Safeguarding This method limits access to the machine haz-ardous areas by the size of the opening or by clos-ing off the danger zone access when the work-pieceis in place in the machine. Operators are preventedfrom reaching the hazard area during the machineoperation; however, employee access to the dangerarea is not adequately guarded when the work-piece is not in place.

Safe Work Procedures Safe work procedures are formal, written instruc-tions which describe how a task is to be performed.These procedures should incorporate appropriatesafe work practices, such as prohibiting employeesfrom wearing loose clothing or jewelry and requir-ing the securing of long hair with nets or caps.Clothing, jewelry, long hair, and even gloves can getentangled in moving machine parts.

Complementary Equipment Complementary equipment is used in conjunctionwith selected safeguarding techniques and it is, byitself, not a safeguarding method. Some commoncomplementary equipment used to augmentmachine safeguarding include:

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Emergency Stop Devices Emergency stop devices are designed to be usedin reaction to an incident or hazardous situationand, as such, are not considered machine safe-guarding. These devices, such as buttons, rope-pulls, cable-pulls, or pressure-sensitive body bars,neither detect nor prevent employee exposure tomachine hazards; rather they initiate an action tostop hazardous motion when an employee recog-nizes a hazard and activates them. (See Figure 20.)

Figure 20 Safety Tripod on a Rubber Mill

Work-Holding Equipment Work-holding equipment is not used to feed or re-move the work-piece, but rather to hold it in placeduring the hazardous portion of the machine cycle.Clamps, jigs, fixtures and back gauges are exam-ples of work-holding equipment. This equipmentmay be used to reduce or eliminate the need for anemployee to place their hands in the hazard area.

Feeding and Ejection Systems A feeding and ejection system (e.g., a gravity fedchute; semi-automatic and automatic feeding andejection equipment), by itself, does not constitutesecondary safeguarding. However, the use of prop-erly designed feed and ejection mechanisms canprotect employees by minimizing or eliminating theneed for them to be in a hazard area during thehazardous motion of the machine.

Hand-Feeding Tools Operators can use tools to feed and remove materi-al into and from machines so as to keep theirhands away from the point of operation. However,this must be done only in conjunction with theguards and safeguarding devices described previ-ously. Hand tools are not point-of-operation guard-

Slide inDownPosition

Slide inUpPositionPoint of

OperationGuard

CompletedPart

Chute

PanShuttle

FeedingTool

Stock

Tripod

ing or safeguarding devices and they need to bedesigned to allow employees hands to remain out-side of the machine danger area. Using hand toolsrequires close supervision to ensure that the opera-tor does not bypass their use to increase produc-tion. It is recommended that these tools be storednear the operation to promote their use.

To prevent injury and repetitive trauma disor-ders, hand-feeding tools should be shatterproofand ergonomically designed for the specific taskbeing performed. (Figure 21 shows typical hand-feeding tools.)

Figure 21 Typical Hand-Feeding Tools

Foot Controls Foot controls that are not securely fixed at a safedistance do not constitute machine safeguardingbecause they do not keep the operators hands outof the danger area. If you use foot-actuated con-trols that are not single-control safeguardingdevices, they will need to be used with some typeof guard or other safeguarding device.

Improperly used foot-actuated controls mayincrease productivity, but the freedom of handmovement increases the risk of a point-of-operationinjury or amputation. Foot controls must be guard-ed to prevent accidental activation by anotheremployee or by falling material. Do not ride thefoot pedal. Ensure that the machine control circuitis properly designed to prevent continuous cycling.(See Figure 22 for an example of a properly guard-ed foot control.)

Figure 22 Properly Guarded Foot Control


Administrative Issues As an employer, you need to consider housekeep-ing practices, employee apparel, and employeetraining. Implement good housekeeping practicesto promote safe working conditions around ma-chinery by doing the following:

Remove slip, trip, and fall hazards from theareas surrounding machines;

Use drip pans when oiling equipment; Remove waste stock as it is generated; Make the work area large enough for machine

operation and maintenance; and Place machines away from high traffic areas to

reduce employee distraction.

Employees should not wear loose-fitting cloth-ing, jewelry, or other items that could becomeentangled in machinery, and long hair should beworn under a cap or otherwise contained to pre-vent entanglement in moving machinery.

Adequate instruction in the safe use and care ofmachines and supervised on-the-job training areessential in preventing amputation injuries. Onlytrained employees should operate machinery.

Train Employees in the Following:

All hazards in the work area, includingmachine-specific hazards;

Machine operating procedures, lockout/tagoutprocedures and safe work practices;

The purpose and proper use of machine safe-guards; and

All procedures for responding to safeguardingproblems such as immediately reporting un-safe conditions such as missing or damagedguards and violations of safe operating prac-tices to supervisors.

In addition to employee instruction and training,employers need to provide adequate supervisionto reinforce safe practices. Take disciplinary ac-tion to enforce safe work practices and workingconditions.

Inspection and Maintenance Good inspection, maintenance and repair proce-dures contribute significantly to the safety of themaintenance crew as well as to the operators. Toensure the integrity of the machinery and machinesafeguards, a proactive, versus a break-down main-

Specific Machine Hazardsand Safeguarding MethodsAs discussed earlier, 8,450 known non-fatal ampu-tation cases (involving days away from work)occurred in 2005 for all of private industry. Themost prevalent injury source was, by far, machin-ery, which accounted for approximately 60% (5,080instances) of the amputation cases.1 The machinerylisted here cause amputation injuries, and appropri-ate safeguarding and hazardous energy control(lockout/tagout) methods are addressed in this sec-tion. Employers need to consult the OSHA standardfor specific machinery to ensure compliance withall requirements. For other types of hazardoussources of injury, see Appendix B.

Machinery Associated with Amputations

1. Mechanical Power Presses2. Power Press Brakes3. Powered and Non-Powered Conveyors4. Printing Presses5. Roll-Forming and Roll-Bending Machines6. Shearing Machines7. Food Slicers8. Meat Grinders9. Meat-Cutting Band Saws

10. Drill Presses11. Milling Machines12. Grinding Machines13. Slitters

Hazards of Mechanical Power Presses Although there are three major types of powerpressesmechanical, hydraulic, and pneumaticthe machinery that accounts for a large number ofworkplace amputations are mechanical powerpresses.

In mechanical power presses, tools or dies aremounted on a slide, or ram, which operates in acontrolled, reciprocating motion toward and awayfrom the stationary bed or anvil containing thelower die. When the upper and lower dies presstogether to punch, shear or form the work-piece, the desired piece is produced. Once thedownstroke is completed, the re-formed work-piece

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tenance program needs to be established basedupon the:

Manufacturers recommendations; Good engineering practice; and Any applicable OSHA provisions (such as the

mechanical power press inspection and mainte-nance requirements, contained in 1910.217(e)).

Lockout/Tagout OSHAs lockout/tagout (LOTO) standard, 29 CFR1910.147, establishes minimum performance re-quirements for controlling hazardous energy and itis intended to complement and augment machinesafeguarding practices. The lockout/tagout standardapplies only if employees are exposed to hazard-ous energy during servicing/maintenance activities.An employer may avoid the requirements of theLOTO standard if the safeguarding method elimi-nates your employees exposure to the machinedanger area during the servicing or maintenancework by using Machinery and Machine Guardingmethods in accordance with the requirements con-tained in 29 CFR 1910, Subpart O.

Additionally, because some minor servicing mayhave to be performed during normal productionoperations, an employer may be exempt fromLOTO in some instances. Minor tool changes andadjustments and other minor servicing operations,which take place during normal production opera-tions, are not covered by lockout/tagout if they areroutine, repetitive and integral to the use of themachine for production and if work is performedusing alternative effective protective measures thatprovide effective employee protection.

In short, a hazardous energy control program isa critical part of an overall strategy to preventworkplace amputations during machine servicingand maintenance activities, such as during the set-ting up of machines for production purposes, by-passing guards to clear jams or lubricate parts, andinspecting, adjusting, replacing, or otherwise serv-icing machine parts. Machine amputations occurwhen an employer does not have or fails to imple-ment practices and procedures to disable and con-trol a machines energy sources during machineservicing and maintenance work.

1 U.S. Department of Labor, Bureau of Labor Statistics(BLS); Annual Survey data, Table R25. Number of non-fatal occupational injuries or illnesses involving daysaway from work by source of injury or illness and select-ed natures of injury or illness, 2005.

is removed either automatically or manually, a newwork-piece is fed into the die, and the process isrepeated. (See Figure 23.)

Figure 23 Part Revolution Mechanical Power Press witha Two-Hand Control

Controls for Machines with Clutches

Certain machines can be categorized based onthe type of clutch they usefull-revolution orpart-revolution. Differing modes of operation forthese two clutches determine the type of guard-ing that can be used.

Full-revolution clutches, once activated, com-plete a full cycle of the slide (lowering and rais-ing of the slide) before stopping at dead centerand cannot be disengaged until the cycle is com-plete. So, presence-sensing devices will notwork and operators must be protected duringthe entire press operating cycle. For example,properly applied barrier guards or two-handtrip devices that are installed at a safe distancefrom the hazard area may be used.

Machines incorporating full-revolutionclutches, such as mechanical power presses,must also incorporate a single-stroke device andanti-repeat feature.

The majority of part-revolution presses areair clutch and brake. They are designed to trapair in a chamber or tube. When the compressedair is put into these chambers, the clutch isengaged, the brake disengaged and the press

makes a single stroke. To stop the press, thereverse takes place. Thus, the part-revolutionclutch can be disengaged at any time during thecycle to stop the cycle before it completes thedownstroke.

For safeguarding purposes, part-revolutionmechanical power presses can be equipped withpresence-sensing devices, but full-revolutionmechanical power presses cannot.

NOTE: Likewise, most hydraulic power pressesand their associated control systems are similar topart-revolution mechanical power presses in thatthe slide can be stopped at any point in the cycle.In order to ensure the integrity of the safety-relatedfunctions, safeguarding devices (such as presence-sensing devices) may only be used on hydraulicpower presses that are properly designed and con-structed (in accordance with good engineeringpractice) to accommodate the safeguarding system.Refer to OSHAs Machine Guarding eTool for addi-tional information on hydraulic presses.

Amputations occurring from the point of opera-tion hazards are the most common types of injuriesassociated with mechanical power presses.Improperly applied safeguarding methods (such asusing a guard with more than maximum allowableopenings or 2-hand palm buttons that are mountedwithin the safety distance of the press) may allowoperators unsafe access to the presss hazardousarea. These unsafe conditions may result in anamputation when an operator, for example, instinc-tively reaches into the point of operation to adjust amisaligned part or release a jam. Also, amputationsoccur when an operators normal feeding rhythm isinterrupted, resulting in inadvertent placement of theoperators hands in the point of operation. Suchinjuries usually happen while the operator is ridingthe foot pedal. Additionally, some amputations arelinked to mechanical (such as the failure of a single-stroke linkage), electrical (such as a control relay fail-ure), or pneumatic (such as the loss of air pressureto the clutch/brake) machine component failure.

Examples of inadequate or ineffective safe-guarding and hazardous energy control practicesinclude the following:

Guards and devices disabled to increase produc-tion, to allow the insertion of small-piece work, orto allow better viewing of the operation.

Two-hand trips/controls bridged or tied-down toallow initiation of the press cycle using only onehand.

Devices such as pullbacks or restraints improp-erly adjusted.


Control Box

Control BoxLight

Curtain

Controls of a single-operator press bypassed byhaving a coworker activate the controls whilethe operator positions or aligns parts in the die,or repairs or troubleshoots the press.

Failure to properly disable, isolate press energysources, and lockout/tagout presses before anemployee performs servicing or maintenancework.

Case History #1While using an unguarded, foot-pedal-operated,full-revolution mechanical power press thatmade trip collars for wood stoves, an employeeused his hands to feed and remove finished partsand scrap metal. He placed the completed part tothe left side of the press, and then turned toplace the scrap in the bin behind him. As heturned back to face the press, he inadvertentlystepped on the foot pedal and activated the presswhile his hand was in the die area. His left handwas amputated at the wrist.

Case History #2An employee was operating an unguarded 10-ton, full-revolution mechanical power press tostamp mailbox parts, and using a hand tool toload the press, she placed her left hand in thelower die to reposition a misaligned part. At thesame time, she inadvertently depressed the footpedal, activating the press and crushing her leftindex finger.

Case History #3A power press operator and helper were instruc-ted to temporarily halt production and eachemployee decided to perform servicing tasks.The operator had a problem with a hydraulicfluid leak and decided to deflect the liquid sprayby installing a temporary barrier while, at thesame time, the helper decided to clean up themetal chips from the press area. The operatorthen activated the press and repositioned thepress slide in order to install the cardboard barri-er. This mechanical power press action fatally crushed the helpers head because his head wasbetween the dies while he was in the process ofcleaning up the metal chips.

Source: OSHA IMIS Accident Investigation Database.

Safeguarding Mechanical Power Presses Mechanical power presses are extremely versatileand selecting appropriate safeguarding methodsdepends on the specific press design and use. Youshould consider the press, the type of clutch used,

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the stock size, the length of production runs, andthe method of feeding.

You can use primary safeguarding methods,such as guards or safeguarding devices, to preventinjuries. For example, 29 CFR 1910.217 requiresemployers to provide and ensure the use of pointof operation guards or properly installed devices onevery operation performed on a press when the dieopening is greater than 1/4 inch.

In addition, guards must conform to the maxi-mum permissible openings of Table O-10 of 29 CFR1910.217. Guards must prevent entry of hands orfingers into the point of operation through, over,under, or around the guard.

Mechanical Power Press Safeguarding Methods by Clutch Type

Full-Revolution Clutch Part-Revolution Clutch

Point of Operation Guard Point of Operation Guard Pullback PullbackRestraint RestraintType A Gate Type A GateTwo-Hand Trip Type B Gate*

Two-Hand Control* Presence-Sensing Device*

*Hands-in-Die operations require additional safe-guarding measures: See 1910.217(c)(5).

Mechanical power press point of operation safe-guards must accomplish the following goals:

Prevent or stop the normal press stroke if theoperators hands are in the point of operation;or

Prevent the operator from reaching into thepoint of operation as the die closes; or

Withdraw the operators hands if inadvertentlyplaced in the point of operation as the die clos-es; or

Prevent the operator from reaching the point ofoperation at any time; or

Require the operator to use both hands for themachine controls that are located at such a dis-tance that the slide completes the downwardtravel or stops before the operator can reachinto the point of operation; or

Enclose the point of operation before a pressstroke can be started to prevent the operatorfrom reaching into the danger area before die closure or enclose the point of operation priorto stoppage of the slide motion during thedownward stroke.

Source: 29 CFR 1910.217(c)(3)(i).

Figure 24 Hand-Feeding Tools Used in Conjunction withPullbacks on a Power Press

Removing scrap or stuck work with tools isrequired even when hand feeding is allowedaccording to 29 CFR 1910.217(d)(1)(ii). Em-ployers must furnish and enforce the use ofhand tools for freeing or removing work orscrap pieces from the die to reduce the amountof time an operators hand is near the point ofoperation.

Control point of operation hazards created whenguards are removed for set-up and repair byoperating the machine in the inch mode. Thisinvolves using two-hand controls (or a singlecontrol mounted at a safe distance from themachine hazards) to gradually inch the pressthrough a stroke when the dies are being testedon part-revolution clutch presses.

Observe energy control procedures and prac-tices for press servicing and maintenance work.For example, the changing of dies on a mechan-ical power press requires the employer to estab-lish a die-setting procedure that employs point-of-operation safeguarding method(s) such as thesafe usage of an inch or jog safety device for dieset-up purposes together with LOTO. Thesedevices safely position the mechanical powerpress slide utilizing a point-of-operation safe-guarding technique. Thus, an energy controlprocedure for these types of presses would


No Hands-in-Die Policy

In general, a no-hands-in-die policy needs tobe implemented and followed whenever possible that is, in the event the press is not designedfor hands-in-die production work. Under thispolicy, operators must never place their hands inthe die area (point-of-operation) while perform-ing normal production operations. Adherence tothis safety practice will reduce the risk of point ofoperation amputations.

In terms of part-revolution mechanical powerpresses that use a two-hand control, presence-sensing device or type B gate, OSHA does allowhands-in-die operation if the press control reli-ability and brake monitoring system require-ments are met. If these press design safety fea-tures are not complied with, then employersmust incorporate a no-hands-in-die policy.

Source: 29 CFR 1910.217(c)(5).

Other Controls for Mechanical PowerPress Servicing and Maintenance Secondary safeguarding methods may be usedalone or in combination (to achieve near equivalentprotection) only when the employer can show thatit is impossible to use any of the primary safe-guarding methods. The following are some workpractices, complementary equipment and energycontrol measures that may be used to supplementprimary safeguarding:

If employees operate presses under a no-hands-in-die policy using complementary feed-ing methods such as hand-tool feeding, employ-ers still must protect operators through the useof primary safeguarding methods, such as aproperly applied two-hand control or trip safe-guarding device. Hand-tool feeding alone doesnot ensure that the operators hands cannotreach the danger area. (Figure 24 illustrates theuse of hand-feeding tools in conjunction withpullbacks on a power press.)

Ram Up-Die Open

Ram Descending-Die Closing

need to integrate both point-of-operation safe-guarding method(s) for slide positioning as wellas LOTO procedures for the die setting opera-tion.

Additional power press energy control precau-tions (e.g., use of safety blocks; LOTO the press dis-connect switch if re-energization presents a hazard)will be necessary if employees need to place theirhands/arms in a press working area (the spacebetween the bolster plate and the ram/slide) toperform the servicing and/or maintenance activity(such as adjusting, cleaning or repairing dies) be-cause the inch or jog safety device will not protectemployees from ram movement due to potentialmechanical energy (resulting from the ram/slideposition and associated gravitational force), presscomponent or control system malfunction, or pressactivation by others.

Minor Servicing

At times, OSHA recognizes that some minorservicing may have to be performed during nor-mal production operations, so a lockout/tagoutexception is allowed. See the 29 CFR 1910.147(a)(2)(ii) Note for details. For example, a press oper-ator may need to perform a minor die cleaningtask on a regular basis for product quality pur-poses and the use of safety blocks insertedbetween the press dies that are interlocked withthe press electrical controls would constituteeffective protection. Properly designed andapplied safety block interlocks may be used inlieu of locking or tagging out the presss electricalenergy source for purposes of the minor servic-ing exception.

Source: 29 CFR 1910.147(a)(2)(ii) Note.

Training Training is essential for employee protection. As anemployer, you should:

Train operators in safe mechanical press opera-tion and hazardous energy control (lockout/tagout) procedures and techniques before theybegin work on the press.

Supervise operators to ensure that correct pro-cedures and techniques are being followed.

Additional Requirements In addition, work practices such as regular mechan-ical power press inspection, maintenance, andreporting are essential.

29 CFR 1910.217(e)(1)(i) requires a program ofperiodic and regular inspections of mechanicalpower presses to ensure that all of the pressparts, auxiliary equipment and safeguards arein safe operating condition and adjustment.Inspection certification records must be main-tained.

29 CFR 1910.217(e)(1)(ii) requires you to inspectand test the condition of the clutch/brake mech-anism, anti-repeat feature, and single-strokemechanism on at least a weekly basis for press-es without control reliability and brake systemmonitoring. Certification records must be main-tained of these inspections and the maintenanceperformed.

29 CFR 1910.217(g)(1) requires the reporting ofall point of operation injuries to operators orother employees within 30 days to either theDirector of the Directorate of Standards andGuidance, OSHA, U.S. Department of Labor,Washington, DC 20210, or the state agencyadministering a plan approved by OSHA. Youcan also use the Internet to report injuries (www.osha.gov/pls/powerpress/mechanical.html).

Applicable Standards

29 CFR 1910.147, Control of hazardous energy(lockout/tagout).

29 CFR 1910.217, Mechanical power presses. 29 CFR 1910.219, Mechanical power-transmis-

sion apparatus.

Sources of Additional Information

OSHA Instruction CPL 3-00-002 [CPL 2-1.35],National Emphasis Program on Amputations

OSHA Publication 3067, Concepts andTechniques of Machine Safeguarding(http://www.osha.gov/Publications/Mach_Safeguard/toc.html)

OSHA Machine Guarding eTool (http://www.osha.gov/SLTC/etools/machineguarding/index.html)

OSHA Lockout/Tagout Interactive TrainingProgram (http://www.osha.gov/dts/osta/ lototraining/index.htm)

NIOSH CIB 49, Injuries and AmputationsResulting From Work with Mechanical PowerPresses (May 22, 1987)

OSHA Instruction STD 01-12-021 [STD 1-12.21]29 CFR 1910.217, Mechanical PowerPresses, Clarifications (10/30/78)

ANSI B11.1-2001, Safety Requirements forMechanical Power Presses

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Power Press Brakes Power press brakes are similar to mechanicalpower presses in that they use vertical reciprocat-ing motion and are used for repetitive tasks. Pressbrake operation is either mechanical or hydraulic.

Press brakes are either general-purpose or spe-cial-purpose brakes, according to ANSI B11.3-2002,Safety Requirements for Power Press Brakes.General purpose press brakes have a single opera-tor control station. A servo-system activates thespecial purpose brake, which may be equippedwith multiple operator/helper control stations. (SeeFigure 25 for a power press brake operation.)

Figure 25 Power Press Brake Bending Metal

Hazards of Power Press Brakes As with mechanical power presses, point of opera-tion injuries are the most common type of injuryassociated with power press brakes. Here are somefrequent causes of amputations from power pressbrakes:

Foot controls being inadvertently activated whilethe operators hand is in the point of operation.The likelihood of this type of injury increases asthe size of stock decreases and brings the opera-tors hands closer to the point of operation.

Parts of the body caught in pinch points createdbetween the stock and the press brake framewhile the bend is being made.

Controls of a single-operator press bypassed byhaving a coworker activate the controls while


the operator positions or aligns stock or repairsor troubleshoots the press.

Failure to properly lockout/tagout presses duringthe necessary tasks of making adjustments,clearing jams, performing maintenance,installing or aligning dies, or cleaning themachine.

Case History #4An operator was bending small parts using an80-ton unguarded press brake. This required theemployees fingers to be very close to the pointof operation; and, consequently, the operator lostthree fingers when his hand entered the pointof operation. The operator on the previous shifthad reported to the supervisor that the opera-tor placed his fingers close to the point of opera-tion, but was told that nothing could be done andthat the operator should be careful.

Case History #5An operator was bending metal parts using a 36-ton part-revolution power press brake that wasfoot-activated and equipped with a light curtain.About 3-4 inches of the light curtain had beenblanked out during a previous part run. Whileadjusting a part at the point of operation, theemployee accidentally activated the foot pedaland amputated three fingertips.

Safeguarding Power Press Brakes Primary safeguarding methods, such as physicalguards and point of operation safeguarding devices(movable barrier devices, presence-sensing de-vices, pull-back devices, restraint devices, single-and two-hand devices) can be used to effectivelyguard power press brakes. (Figure 26 shows a gen-eral-purpose power press brake used in conjunc-tion with pullbacks.) Some safeguarding methods,such as presence-sensing devices, may requiremuting or blanking to allow the bending of materi-al. Always ensure that these safety devices areproperly installed, maintained, and used in accor-dance with the manufacturers guidelines for thespecific stock and task to be performed. Failure todo so could leave sensing field channels "blankedout" and expose operators to point-of-operation hazards as the safeguarding devices safety dis-tance increases when blanking is used.

Press Bed

Point of Operation

Figure 26 Two-Person Power Press Brake Operationwith Pullbacks

In other instances, such as with special-purposepower press brakes, machines are equipped withadvanced control systems that are adaptable to allforms of safeguarding concepts and devices, suchas two-hand controls and multiple operator/helperactuating controls. For example, two-hand down,foot through (actuation) methods are used to safe-guard employees while they operate press brakes.With this safeguarding system, an operator uses atwo-hand control to lower the press brake ram, forexample, to within 1/4 inch or less of the lower die(which is considered a safe opening). The operatorthen has the ability to maneuver and align thework-piece within this 1/4 inch safe opening areaand he or she is protected from the amputationhazard. Then the foot control is used by the opera-tor to safely actuate the machine to produce thedesired product.

Because of constraints imposed by certain man-ufacturing or fabricating processes, safeguardingby maintaining a safe distance from the point ofoperation may be acceptable. However, this is per-mitted only when safeguarding by barrier guardor safeguarding devices is not feasible (impossi-ble) that is, where the use of primary safeguard-ing method (such as a restraint device) is not fea-sible. Additional information about a safe distancesafeguarding program can be found in OSHAInstruction 02-01-025 [CPL 2-1.25] Guidelines forPoint of Operation Guarding of Power PressBrakes.

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Other Controls for Power Press Brakes The following are some secondary safeguardingmethods and complementary equipment that maybe used to supplement primary safeguarding oralone or in combination when primary safeguard-ing methods are not feasible:

Safe distance safeguarding, Safe holding safeguarding, Safe work procedures, Work-holding equipment (such as back gauges), Properly designed and protected foot pedals,

and Hand-feeding tools.

Ensure that proper safeguarding and lockout/tagout procedures are developed and implementedfor power press brakes. Train and supervise em-ployees in these procedures and conduct periodicinspections to ensure compliance.

Applicable Standards

29 CFR 1910.147, Control of hazardous energy(lockout/tagout).

29 CFR 1910.212, General requirements for allmachines.

29 CFR 1910.219, Mechanical power-transmis-sion apparatus.




OSHA Lockout/Tagout Interactive TrainingProgram (http://www.osha.gov/dts/osta/ lototraining/index.htm)

OSHA Directive CPL 02-01-025 [CPL 2-1.25],Guidelines for Point of Operation Guarding ofPower Press Brakes

ANSI B11.3-2002, Safety Requirements forPower Press Brakes

Hazards of Conveyors Conveyors are used in many industries to transportmaterials horizontally, vertically, at an angle, oraround curves. Many conveyors have different andunique features and uses, so that hazards vary due

Wristlets

Point of Operation

Press Bed

to the material conveyed, the location of the con-veyor, and the proximity of the conveyer to theemployees. Types include unpowered and pow-ered, live roller, slat, chain, screw, and pneumatic.Conveyors eliminate or reduce manual materialhandling tasks, but they present amputation haz-ards associated with mechanical motion. (SeeFigures 27 through 30 for examples of commonconveyors.)

Conveyor-related injuries typically involve aemployees hands or fingers becoming caught innip points or shear points on conveyors and mayoccur in these situations:

Cleaning and maintaining a conveyor, especiallywhen it is still operating.

Reaching into an in-going nip point to removedebris or to free jammed material.

Allowing a cleaning cloth or an employeesclothing to get caught in the conveyor and pullthe employees fingers or hands into the con-veyor.

Other conveyor-related hazards include improp-erly guarded gears, sprocket and chain drives, hori-zontal and vertical shafting, belts and pulleys, andpower transmission couplings. Overhead convey-ors warrant special attention because most of theconveyors drive train is exposed. Employees havealso been injured or killed while working in areasunderneath conveyors and in areas around lubrica-tion fittings, tension adjusters, and other equipmentwith hazardous energy sources.

Case History #6While removing a cleaning rag from the ingoingnip point between the conveyor belt and its tailpulley (the unpowered end of the conveyor), anemployees arm became caught in the pulley,which amputated his arm below the elbow.

Case History #7While servicing a chain-and-sprocket driveassembly on a roof tile conveyor system, anemployee turned off the conveyor, removed theguard, and began work on the drive assemblywithout locking out the system. When someonestarted the conveyor, the employees fingersbecame caught in the chain-and-sprocket driveand were amputated.


Figure 27 Belt Conveyor

Figure 28 Screw Conveyor

Figure 29 Chain Driven Live Roller Conveyor

Fixed Guard OverPower-TransmissionApparatus

Belt

In-Running Nip

Some guards and covers are not shown to facilitateviewing of moving parts. Equipment must not beoperated without guards and covers in place.


In-Running Nip Point

Fixed Guard


Screw

Rotating Motion

Fixed Guard


Chain


Fixed Guard

Sprocket

Roller

Figure 30 Slat Conveyor

Safeguarding Conveyors As conveyor hazards vary depending on the appli-cation, employers need to look at each conveyor toevaluate and determine what primary safeguardingmethods and energy control (lockout/tagout)practices are required. Where necessary for theprotection of employees, conveyors need to havemechanical guards that protect the employee fromnip points, shear points, and other moving parts,including power-transmission apparatus. Guardsmay include barriers, enclosures, grating, fences, orother obstructions that prevent inadvertent physicalcontact with operating machine components, suchas point of operation areas, belts, gears, sprockets,chains, and other moving parts. A brief descriptionof the hazards and recognized safeguarding meth-ods is presented for common types of conveyors.

Typical Conveyor Hazards and Safeguarding Methods

Belt Conveyors

Hazards: Belt-conveyor drive mechanisms andconveying mediums are hazardous as are the fol-lowing belt-conveyor areas: 1) conveyor take-upand discharge ends; 2) where the belt or chainenters or exits the in-going nip point; 3) wherethe belt wraps around pulleys; 4) snub rollerswhere the belt changes direction, such as take-ups; 5) where multiple conveyors are adjoined;or 6) on transfers or deflectors used with beltconveyors.

Controls: The hazards associated with nip andshear points must be safeguarded. Side guards(spill guards), if properly designed can preventemployee contact with power-transmission com-ponent, in-going nip points and the conveying

medium. Secondary safeguarding methods forhazard control include the use of standard railingsor fencing, or safeguarding by distance (location),and installing hazard awareness devices, such aspre-start-up signals and warning signs.

Screw Conveyors

Hazards: Screw conveyors are troughs with arevolving longitudinal shaft on which a spiral ortwisted plate is designed. In-going nip points, ofturning helical flights for the entire length of thescrew conveyor, exist between the revolvingshaft and trough. Since the trough is not usuallyrequired to be covered for proper operation ofthe conveyor and because many screw convey-ors are located at or near the floor level, the haz-ard of stepping into the danger area is ever pres-ent. Once caught, the victim is pulled further intothe path of the conveying medium.

Controls: A screw conveyor housing must com-pletely enclose the moving elements (screwmechanism, power transmission apparatus) ofthe conveyor, except for the loading and dis-charge points. Permanently affixed grids or poly-carbonate can be installed for visibility purposesto allow the operator to inspect the operation.Alternatively, the trough side walls should behigh enough to prevent employees from reach-ing over and falling into the trough. Opentroughs can be used if covers are not feasible;but employees need to be protected by second-ary safeguarding methods, such as a railing orfence.

Feed loading and discharge points can usuallybe guarded by providing enclosures, screening,grating, or some other interruption across theopenings which will allow the passage of thematerial without allowing the entry of a part ofthe employees body into the moving part(s).

Chain Conveyors

Hazards: Nip points occur when a chain contactsa sprocket, such as when a chain runs around asprocket or when the chain is supported by asprocket or when a shoe above the chain pre-cludes the chain from lifting off the sprocket. Nippoints also occur at drives, terminals, take-ups(automatic take-ups may also have shear points),and idlers. Employee clothing, jewelry, and longhair may also get entangled and caught in themoving chain conveyor.

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Fixed Guard

Slats

Controls: Sometimes, moving chains cannot beenclosed without impairing the functioning of theconveyor. However, in some cases, barrierguards may be installed around the moving partsfor hazard enclosure purposes or, in other in-stances, nip and shear points may be eliminatedby placing a guard at the nip point or shearpoint. Other secondary safeguarding optionsinclude safeguarding by distance (location) andthe use of awareness devices.

Roller Conveyors

Hazards: Roller conveyors are used to movematerial on a series of parallel rollers that areeither powered or gravity-fed. Powered rollerconveyors have the hazard of snagging andpulling objects, including hands, hair, and cloth-ing into the area between the rollers and the sta-tionary components of the conveyor. In-goingnip points generally exist between the drivechain and sprockets; between belt and carrierrollers; and at terminals, drives, take-ups, idlers,and snub rollers.

Controls: Roller conveyors need to, where feasi-ble, have permanent barrier guards that can beadjusted as necessary to protect the employeefrom nip and shear points. For example, theunused section of rollers closest to the employ-ees needs to be guarded when transportingsmall items on a roller conveyor that do notrequire the use of the entire roller width. Also,conveyor hazards may be reduced by eliminatingor minimizing projections from the roller andthrough the use of pop-up rollers. Other second-ary safeguarding options include safeguardingby distance (location) and the use of awarenessdevices.

Other Controls for Conveyors The following are some secondary safeguardingmethods, work practices, and complementaryequipment that may be used to supplement pri-mary safeguarding or alone or in combinationwhen primary safeguarding methods are not feasi-ble:

Safeguarding by safe distance (by location) locating moving parts away from employees toprevent accidental contact with the hazardpointis one option for safeguarding convey-ors. It is particularly difficult, however, to use

this method when employees need to be at ornear unguarded moving parts.

Use prominent awareness devices, such aswarning signs or lights, to alert employees tothe conveyor operation.

Allow only trained individuals to operate con-veyors and only trained, authorized staff to per-form servicing and maintenance work.

Visually inspect the entire conveyor and imme-diate work area prior to start-up to determinethat the actuation will not cause an employeehazard.

Inspect and test conveyor safety mechanisms,such as its alarms, emergency stops, and safe-guarding methods.

Do not use any conveyor which is unsafe until itis made safe.

Forbid employees from riding on conveyors. Prohibit employees working with or near con-

veyors from wearing loose clothing or jewelry,and require them to secure long hair with a netor cap.

Install emergency stop devices on conveyorswhere employees work when they cannot other-wise control the movement of the conveyor.This recognized safety feature provides employ-ees with the means to shut off the equipment inthe event of a hazardous situation or emergencyincident.

For emergency stop devices, you will need theseengineering controls:

Equip conveyors with interlocking devices thatshut them down during an electrical or mechani-cal overload such as product jam or other stop-page. Emergency devices need to be installed sothat they cannot be overridden from other loca-tions.

When conveyors are arranged in a series, allshould automatically stop whenever one stops.

Equip conveyors with emergency stop controlsthat require manual resetting before resumingconveyor operation.

Install clearly marked, unobstructed emergencystop buttons or pull cords within easy reach ofemployees.

Provide continuously accessible conveyor beltswith emergency stop cables that extend theentire length of the conveyor belt to allow access tothe cable from any point along the belt.

Ensure that conveyor controls or power sourcescan accept a lockout/tagout device to allow safemaintenance practices.





OSHA Lockout/Tagout Interactive Tra

osha guide

Documents

safeguarding roll

safeguarding devices

safeguarding conveyors

hazards of roll

workplace safety

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hazards of power press

safeguarding machinery