M A C H I N E S A F E G UA R D I N G A D M I N I S T R AT I V E G U I D E

Transcription

1 M A C H I N E S A F E G UA R D I N G A D M I N I S T R AT I V E G U I D E

2 2009 Comprehensive Loss Management, Inc. This material is the property of CLMI Safety Training and may not be reproduced or distributed in any manner. When permitted, you may print a single copy of this material for your personal use.

3 Machine Safeguarding Instructions Instructions Welcome To The Safety Program! This is one in a series of comprehensive programs that provide unique safety solutions for companies faced with limited time, money and resources. This program is designed to provide a step-by-step, color-coded guide for individuals with limited knowledge of safety management, training or compliance. The program is written in an uncomplicated, easy-to-follow style. Clear and simple explanations of the topic are included, and the Take A Closer Look sections provide more detailed information. The program has the following sections: Introduction This section provides information on the topic and the training benefits for your company and employees. The program s goals are defined as well as how these goals can be incorporated into your safety training efforts. How To Comply This section explains the steps you can take to help employees avoid injuries and reduce related costs to your company. Written Program This section includes a sample written program along with forms that will help you customize the written program to fit your company s needs. Training OSHA compliance also requires employee training. This section provides a complete training guide and tools, including these materials: An Instructor Guide that provides objectives, discussion questions, training techniques and follow-up activities to support the trainer in conducting an effective training session. A video that provides important information to employees in an effective and interesting style. Designed to educate employees on information that may be unfamiliar to the trainer, the video takes a positive, upbeat approach that s entertaining as well as informative. An Employee Handbook that provides information for employees during training and also serves as a reference tool after training has been completed. A Learning Exercise to test employees knowledge and determine their level of understanding about the topic. A Glossary Of Terms. A PowerPoint presentation. Page i

4 Machine Safeguarding Instructions All of the programs in this series have been developed by Certified Safety Professionals (CSPs) with backgrounds in safety training and compliance for all types of industries. This unique package is the most effective and easy-to-use program available, guiding the program administrator step by step through the safety and compliance requirements. UNDERSTANDING THE SYMBOLS Take A Closer Look This symbol identifies material that provides a more detailed explanation of the summary information given previously. The Note This symbol identifies information that the reader should take note of or refers the reader to another section in the manual for additional information. Caution This symbol indicates important points in the program that the reader needs to understand. Video This symbol indicates that you should show the video. Question This symbol indicates that you should ask a question. Slide This symbol indicates that you should show a slide. Handbook This symbol indicates that you should refer to the Employee Handbook. Flipchart This symbol indicates that you should use the flipchart. Helpful Hint ADD EXAMPLES Add Examples This symbol indicates that you should add specific information about your organization. Page ii

5 Machine Safeguarding Instructions Table Of Contents Page # Introduction I-1 How To Comply H-1 Explanation Of The OSHA Standards H-1 How To Develop Your Machine Safeguarding Program H-8 OSHA Standards 29 CFR , 213, 214, 215, 216, 217, 218, 219, 243 Written Program W-1 Written Program Development W-1 Machine Safeguarding Written Program W-3 Recordkeeping W-6 Training T-1 Instructor Guide T-1 Delivery Manager/Supervisor Session Delivery T-6 Operator/Employee Session Delivery T-23 Training Tips T-29 Learning Exercise T-32 Glossary Of Terms T-34 Slides T , 2002, 2007 Comprehensive Loss Management, Inc. Page iii

6 Machine Safeguarding Instructions The information contained in this program has been developed in good faith and is believed to present good safety principles. CLMI and all other participating organizations make no representations or warranties as to the completeness or accuracy thereof. Persons using this information must make their own determination as to its suitability for their purposes in support of their own safety programs. CLMI and all other participating organizations are in no way responsible for damages of any nature resulting from the use of this information. Technical expertise provided by: Richard R. Johnson, CSP Richard A. Pollock, CSP Joe Frederichs Gary Krug, Jr., MS David Volker Page iv 1995, 2002, 2007 Comprehensive Loss Management, Inc.

7 Machine Safeguarding Introduction Introduction Machine Safeguarding Over the last 100 years, as the use of machinery has increased in the workplace, so has the number of machine-related injuries. According to the National Safety Council, injuries such as crushed hands and arms, severed fingers and blindness now account for a significant number of all workplace injuries. In many cases, the injuries are serious enough to affect employees ability to continue to work sometimes, permanently. In addition to the costs to injured workers, there are additional costs to employers: medical payments, workers compensation, lost work days and supervisory time. One important means of keeping the workplace safe is machine safeguarding, which refers to specific control methods designed to prevent employees from being injured by potentially dangerous machines and related procedures. By understanding where the hazards exist in your workplace, you can help ensure that proper safeguards are in place to protect employees. In addition, all employees who work with potentially hazardous machinery or operations need to understand how machine safeguards work and how to use them to prevent injury. To some, safeguarding may seem unnecessary. They would argue that injuries should be prevented by common sense. But in fact, many factors can lead to injuries around unguarded machines: Inattentiveness or boredom Emotional issues, such as anger Haste Distractions Unsafe procedures Production pressures There is also the No one would be foolish enough to... syndrome that is, the belief that if a hazard is evident, no one will get hurt. In reality, given the right set of circumstances, any employee can make a mistake that might lead to injury. In sum, machine guards and shields prevent any action caused by one of these factors from leading to an injury. Machine safeguarding attempts to take the human factor out of the situation. And the savings from preventing even one serious injury far outweigh the costs of providing the safeguarding. Page I-1

8 Machine Safeguarding Introduction This guide is designed to provide a step-by-step approach to developing a machine safeguarding program for your company. Creating such a program will help you understand the following: Why safeguarding is important What types of mechanical and nonmechanical hazards exist in your workplace What types of actions may pose hazards How safeguards should be used to reduce the hazards How employees should be trained to understand the use of safeguards The outcomes of your machine safeguarding program will be as follow: Identification of the mechanical and other hazards posed by the equipment and machinery in your workplace Selection and use of proper safeguards Well-trained employees who know how to protect themselves from machine-related hazards Compliance with OSHA requirements By creating a program for machine safeguarding in the workplace, you can help everyone understand the importance of working in ways that reduce the risk of injury, control the costs associated with those injuries and increase everyone s safety. For additional information about machine safeguarding, consult the following: Your safety equipment supplier Industry trade groups or other similar organizations Your insurance company s loss-control department Consultants and safety councils Machinery manufacturers Suppliers of specialized equipment guarding systems Page I-2

9 Machine Safeguarding How To Comply How To Comply This section contains the following topics: Explanation Of The OSHA Standards How To Develop Your Machine Safeguarding Program OSHA Standards 29 CFR , 213, 214, 215, 216, 217, 218, 219, 243 Explanation Of The OSHA Standards The Occupational Safety And Health Administration (OSHA) has established Standard 29 CFR 1910, Subpart O, Machinery And Machine Guarding, which includes several standards that cover the use of machine safeguards in the workplace. These standards cover the following specific topics: 29 CFR General Requirements For All Machines 29 CFR Woodworking Machinery 29 CFR Cooperage Machinery 29 CFR Abrasive Wheel Machinery 29 CFR Mills And Calenders In The Rubber And Plastics Industries 29 CFR Mechanical Power Presses 29 CFR Forging Machines 29 CFR Mechanical Power-Transmission Apparatus 29 CFR Guarding Of Portable Powered Tools You ll find the complete standards following this section. In addition to these standards, several others cover safeguarding in special industries: 29 CFR Pulp, Paper And Paperboard Mills 29 CFR Sawmills We ll go into more detail later in this guide, but in brief, the standards covering machine safeguards require that you verify that safeguards are used to protect all employees against injuries caused by contact with machines in the workplace. Here s a brief look at 29 CFR General Requirements For All Machines: One or more methods of machine guarding must be provided to protect the operator and other employees in the area from such hazards as these: Point of operation Ingoing nip points Rotating parts Flying chips and sparks The guard must be affixed to the machine, if possible, and the guard itself should not create a hazard. If the operation of a machine could injure an employee, its point of operation (the area where the work is actually performed on the material) must be guarded. The guard must be designed and constructed to prevent any part of the operator s body from being in the danger zone during the operating cycle. Page H-1

10 Machine Safeguarding How To Comply Revolving drums, barrels and containers must have enclosure guards interlocked with the drive mechanism so they cannot revolve unless the guard is in place. Fans less than 7 feet above the floor or working level must be guarded, and the guards must have openings no larger than 1/2 inch. Machines designed for fixed locations must be securely anchored. In addition to these general requirements, OSHA has established several standards to cover specific activities in the workplace. Here are the standards and the activities and equipment they cover: 29 CFR Woodworking Machinery Machine construction, general Machine controls and equipment Hand-fed ripsaws Hand-fed crosscut table saws Circular resaws Self-feed circular saws Swing cutoff saws Radial saws Bandsaws and band resaws Jointers Tenoning machines Boring and mortising machines Wood shapers and similar equipment Planing, molding, sticking and matching machines Profile and swing-head lathes and wood heel turning machines Sanding machines Veneer cutters and wringers Miscellaneous woodworking machines Inspection and maintenance of woodworking machinery 29 CFR Cooperage Machinery This section has been reserved pending future developments. Page H-2

11 Machine Safeguarding How To Comply 29 CFR Abrasive Wheel Machinery General requirements: Machine guarding Guard design Flanges Work rests Excluded machinery Guarding of abrasive wheel machinery: Cup wheels Guard exposure angles Bench and floor stands Cylindrical grinders Surface grinders and cutting-off machines Swing frame grinders Automatic snagging machines Top grinding Exposure adjustment Material requirements and minimum dimensions Band-type guards, general specifications Guard design specifications Flanges: General requirements Finish and balance Uniformity of diameter Recess and undercut Blotters (compressible washers) Driving flanges Dimensions Repairs and maintenance Mounting: Inspection Arbor size Surface condition Bushings Blotters (compressible washers) Multiple wheel mounting Page H-3

12 Machine Safeguarding How To Comply 29 CFR Mills And Calenders In The Rubber And Plastics Industries General requirements Mill safety controls: Safety trip control Auxiliary equipment Calender safety controls: Safety trip, face Safety trip, side Protection by location: Mills Calenders Trip and emergency switches Stopping limits: Determination distance of travel Stopping limits for mills Stopping limits for calenders 29 CFR Mechanical Power Presses General requirements: Reconstruction and modification Excluded machines Mechanical power press guarding and construction, general Safeguarding point of operation Design, construction, setting and feeding of dies Inspection, maintenance and modification of presses Operation of power presses Reports of injuries to employees operating mechanical power presses Presence-Sensing Device Initiation (PSDI) Appendix A: Mandatory requirements for certification/validation of safety systems for Presence-Sensing Device Initiation of mechanical power presses Appendix B: Nonmandatory guidelines for certification/validation of safety systems for Presence-Sensing Device Initiation of mechanical power presses Appendix C: Mandatory requirements for OSHA recognition of third-party validation organizations for the PSDI standard Appendix D: Nonmandatory supplemental information Page H-4

13 Machine Safeguarding How To Comply 29 CFR Forging Machines General requirements: Use of lead Inspection and maintenance Hammers and presses Hammers, general Presses Power-driven hammers Gravity hammers Forging presses Trimming presses Upsetters Other forging equipment Other forge facility equipment 29 CFR Mechanical Power-Transmission Apparatus General requirements Prime-mover guards Shafting Pulleys Belt, rope and chain drives Gears, sprockets and chains Guarding friction drives Keys, setscrews and other projections Collars and couplings Bearings and facilities for oiling Guarding of clutches, cutoff couplings and clutch pulleys Belt shifters, clutches, shippers, poles, perches and fasteners Standard guards, general requirements Approved materials Care of equipment 29 CFR Guarding Of Portable Powered Tools Portable powered tools Pneumatic powered tools and hose Portable abrasive wheels Explosive actuated fastening tools Power lawnmowers We ll go through a detailed, step-by-step process for creating a written program in the section following the OSHA standards. Page H-5

14 Machine Safeguarding How To Comply Machine Safeguarding Definitions To help you understand machine safeguarding, here are some basic definitions: Administrative Controls: Methods of controlling hazards such as job rotation, varying task or work assignments and reducing exposure times. Anti-Repeat Device: A device that limits the machine to a single stroke and requires the release of all tripping mechanisms before another stroke can be started; also known as single-stroke reset or reset circuit. Anti-Tiedown Device: A device that prevents one control in a two-hand control device from being tied down or otherwise defeated. Bending: A mechanical action that turns and forces material to submit, resulting in strain or tension. Calender: A machine equipped with two or more metal rolls revolving in opposite directions and used for continuously sheeting or plying up rubber and plastics compounds and for coating materials with rubber and plastics compounds. Cutting: A mechanical action caused by the motion of machine parts, tools or materials that could sever or lacerate parts of the body. Device: In safeguarding, a control or attachment that inhibits normal operation of a machine if any portion of an employee s body is within a hazardous area. Distance: A safeguarding method in which the hazardous portion of a machine is placed vertically or horizontally out of reach to prevent inadvertent contact with or access to a dangerous part. Enclosure: A fixed physical barrier that prevents fingers, hands, other body parts and clothing from reaching through, under, over or around the safeguard to the point of operation. Also known as a guard. Engineering Controls: Physical changes made in the workplace to improve equipment and work processes to reduce hazards. Fencing: A locked fence or rail enclosure that restricts access to the machine, except by authorized personnel. Gate: A movable barrier that must be moved to enclose the point of operation before the machine can be started. Guard: A protective barrier that prevents employees from coming into contact with the point of operation of a machine. See definition for enclosure above. Hazard: Anything that presents a danger to employees or property. Hazard Control: Any method used to reduce or eliminate a hazard, such as the following: Engineering controls Administrative controls Personal Protective Equipment (PPE) Housekeeping Safe work practices Training Page H-6

15 Machine Safeguarding How To Comply Machine Safeguarding Definitions (continued) Injury: Physical harm or damage to the body resulting from contact with mechanical, chemical, thermal or other environmental energy. Interlocked Guard: A guard that s connected to the machine controls so the machine will not operate if the guard is open or removed. Location: A safeguarding method in which a hazardous machine or component is placed where employees will not normally be. Material: The specific piece of wood, metal, plastic or other object that a machine is performing work on. Nip Point: A hazardous area created by two or more closely spaced, parallel axis mechanical parts rotating in opposite directions. Operating Controls: The area or areas of a machine that contain levers, switches and other devices used to start, stop and regulate machine operation. OSHA (Occupational Safety And Health Administration): A federal agency of the Department Of Labor that regulates workplace safety and health. Personal Protective Equipment (PPE): Equipment worn by employees to protect them from hazards. Pinch Point: Any place where a body part can be caught between two or more moving parts. Point Of Operation: The area on a machine at which work is performed on the material being processed. Power Transmission: All mechanical parts that transmit energy and motion from the source of power to the equipment or machine. Presence-Sensing Device: A device that detects whether an employee s fingers or hands are or could be in the point of operation; if they are, the device stops the machine quickly enough to prevent injury. Reciprocating/Transverse: A mechanical motion moving in a straight line or back and forth that could result in an employee being caught in or struck by fixed or moving objects. Rotating: A movement of turning around a central point or axis. Safeguarding: Any means of preventing employees from coming into potentially harmful contact with the moving parts of machinery or equipment. Shear Point: A hazardous area created by a cutting movement of a mechanical part past a stationary point on a machine. Shield: A physical device positioned between the hazard and the operator that helps reduce machine hazards by deflecting chips, sparks or inadvertent contact by the operator. Single-Stroke Mechanism: An arrangement used on a full revolution clutch to limit the travel of the slide to one complete stroke at each engagement of the clutch. Two-Hand Control: A device that requires an operator to place pressure on a control with each hand during all or most of the machine operation, so that hands cannot be in the point of operation when they are on the controls. Page H-7

16 Machine Safeguarding How To Comply How To Develop Your Machine Safeguarding Program Developing a machine safeguarding program involves five steps: STEP 1) STEP 2) STEP 3) STEP 4) STEP 5) Identify Resources Identify Hazards Control Hazards Develop Safeguarding Procedures Provide Machine Safeguarding Training We ll go through each of these steps individually, taking a closer look at the important information you ll need to know as you develop your program. Additional titles in this series that can provide information on machine safeguarding include the following: Lockout/Tagout Hearing Conservation Personal Protective Equipment STEP 1) Identify Resources The first step in implementing a machine safeguarding program is to identify what resources can help you assess the machine safeguarding requirements in your workplace. Every workplace and particular machine requires specific safeguarding methods, and providing those safeguards can be highly technical. As a result, you may want to seek advice and assistance from external sources, including any of these: Machine suppliers and manufacturers Safeguarding equipment suppliers and manufacturers Safety consultants OSHA State and local safety agencies Industrial associations Page H-8

17 Machine Safeguarding How To Comply In addition, you probably have a great deal of expertise within your organization. Consult these internal resources: Supervisors and managers Engineers Maintenance personnel Machine operators Purchasing personnel to help you write new machine specifications that include compliant machine guards and controls. These individuals should be included as you prepare to implement your machine safeguarding program. Logically, the people who work most closely with the machinery will be best able to identify hazards along with the most effective safeguarding methods. Establishing A Machine Safeguarding Committee One of the most effective ways to access those people with knowledge within your organization is to establish a machine safeguarding committee. This committee can help promote employee involvement in machine safeguarding and tap expertise from all levels of the organization for improving machine safeguarding. Make sure the committee has a specific, clearly defined purpose. The more specific the focus of the committee, the more tangible its results will be. It s important that the committee has the support and active involvement of top management. Such support may be demonstrated by having these individuals attend meetings or review the minutes and activities of meetings. In addition, management must provide the resources necessary for the committee (including time away from members specific job activities) and the willingness and funding to take action on committee suggestions. When forming the committee, select people who represent a cross-section of employees, supervisors and managers and who have an interest or expertise in machine safeguarding. By doing so, you will bring a wide variety of viewpoints, ideas and expertise to the issue and prevent the committee from becoming stagnant as members change and as goals are achieved or reassessed. The committee s progress should be monitored, including cost effectiveness. Actions and results of the committee should be measured, communicated and rewarded. The committee should clearly understand the company policy on safety, so they can develop a system that supports good safeguarding practices and procedures. Page H-9

18 Machine Safeguarding How To Comply Machine Safeguarding Committee Effectiveness Follow these simple guidelines to help ensure that your machine safeguarding committee will be effective in increasing workplace safety: Keep the committee as small as possible so as to encourage all members to actively participate. If more members are needed to accomplish committee activities, divide tasks into subtasks and form subcommittees. The committee should meet as often as necessary to complete the tasks at hand; this may be once per quarter or as often as daily. Minutes of each meeting should be recorded and then distributed to committee members, management and other interested parties. Committee members should be notified of the date, time and place of each upcoming meeting, along with the specific agenda. Establish an agenda for each meeting. Start meetings on time, and stick to an agreed upon meeting length. Structure discussion of all agenda topics as follows: Topic introduction Desired outcome statement Discussion of options Selection of action items Assignment of roles and responsibilities (Who will do what by when? ) Make sure that no single member dominates the meeting; allow for full participation by all members. Establish and assign specific action items that will be completed before the next meeting. STEP 2) Identify Hazards The next step in developing a machine safeguarding program is to identify the machine hazards that exist in your workplace. Most of these hazards will involve machines with moving parts that can injure employees who come into contact with them. New machines that arrive from the manufacturer are not necessarily compliant or safe. Unless you specify that the machine must comply with relevant safety standards as a condition of purchase, it probably won t. In preparing for your survey keep in mind that your workplace may contain machines that aren t equipped with manufacturer safeguards, older equipment that doesn t have safeguarding or existing machines on which safeguards have been removed or disabled. In some cases, you may be developing your own automated equipment for product assembly or packaging, which will require custom engineered safeguarding. You can identify machinery hazards in your workplace by performing a survey. Doing so will involve walking through your workplace and looking for hazards on machinery that could cause injury. To help you complete your workplace survey, a Machine Safeguarding Hazard Assessment Form has been included in the Written Program section. Page H-10

19 Machine Safeguarding How To Comply Types Of Hazards Any piece of machinery that has moving parts can pose a hazard. As you conduct your workplace survey, look for the following types of hazards: Mechanical hazards: Motions Actions Other hazards: Electrical Noise Chemical Types Of Hazards The major types of machinery hazards that can cause injury to employees are divided into two major categories: mechanical hazards and other hazards. Mechanical Hazards Mechanical hazards are divided into two main categories: Motions: Rotating motions can cause injury by catching clothing, forcing arms or hands into dangerous positions or catching hands or fingers in nip points. Reciprocating motions (back and forth or up and down) can be hazardous because employees can be struck by or caught between moving and stationary parts. Transverse motions (movements in straight, continuous lines) create hazards because employees can be struck by or caught in pinches or shear points by moving parts. Actions: Cutting action involves a rotating, reciprocating or transverse motion. The hazard is caused at the point of operation, where finger, head and arm injuries can occur. In addition, flying chips or scrap material can strike the eyes or face. Punching action occurs when power is applied to a slide (ram) for the purpose of blanking, drawing or stamping metal or other material. The hazard occurs at the point of operation where material is inserted, held and withdrawn by hand. Shearing action involves applying power to a slide or knife in order to trim or shear metal or other material. The hazard occurs at the point of operation where material is actually inserted, held and withdrawn. Bending action results when power is applied to a slide in order to draw or stamp metal or other material. The hazard occurs at the point of operation where material is inserted, held and withdrawn and in the space where the material can swing up during bending. Other Hazards It s important to be aware of other hazards that exist in the workplace, including the following: Electrical: All power sources for machinery are potential sources of hazard, as are any open conductors that employees may come into contact with. To protect employees from electrical shocks and electrocution, all machinery that s powered or controlled by electricity should be properly grounded and any wiring that s frayed, exposed or old should be replaced. Noise: Machines often produce noise (unwanted sound) that can be hazardous to employees. Page H-11

20 Machine Safeguarding How To Comply Types Of Hazards (continued) Noise can create these hazards: Cause harmful health effects, including hearing loss Startle employees Disrupt concentration Interfere with communications, hindering job performance Chemical: Some equipment requires the use of hazardous chemicals that can cause injury or illness if employees come into contact with them. Personal Protective Equipment (PPE) and ventilation can provide temporary solutions until such hazards can be better controlled or eliminated. Controls: Every machine must be equipped with a clearly labeled START STOP and EMERGENCY STOP control. The start button should be green. The stop button should be red and the Emergency Stop button should be red with a yellow background. The controls should be located at the operator's position and the use of the controls should not present a hazard to the operator by having to reach over or past another machine hazard to use them. As you examine these types of hazards, concentrate on those specific areas on machines where injuries could occur: Nip points Shear points Pinch points Points of operation Power transmission equipment Hazard Areas On Machinery Machinery can have several specific hazard areas, including the following: Nip points: Parts that rotate in opposite directions while their axes are parallel to each other form a nip point where they come together. If material is being fed between two rotating rolls, it produces two nip points. Another type of nip point is created between rotating parts and other moving parts, such as the point of contact between a chain and a sprocket. A third type of nip point is created between rotating and fixed parts, which create a shearing, crushing or abrading action. Shear points: A shear point is created by the cutting movement of a mechanical part past a stationary point on a machine. Pinch points: A pinch point is any place where a body part can be caught between two or more moving parts. Points of operation: This refers to the area on a machine where work is actually being performed on material. Power transmission equipment: This includes all mechanical parts that transmit energy and motion from the source of power to the equipment or machine. Here are some examples: Gears Pulleys Brakes Cams Belts Rods Shafts Clutches Page H-12

21 Machine Safeguarding How To Comply STEP 3) Control Hazards Once you have identified the hazards present in your workplace, the next step is to control them through the use of safeguards. Safeguarding is an engineering control designed to eliminate hazards at the source without relying on employees behavior for effectiveness. Engineering controls should always be the first choice for eliminating hazards. There are many different types of safeguarding, but they all must meet some general minimum requirements: Prevent contact. Be secure. Provide protection from objects falling into the equipment. Create no new hazards. Do not cause interference with operation. Allow safe lubrication and maintenance. When controlling hazards, keep in mind that safeguarding should not interfere with quality. All safeguards should allow employees to work at the necessary pace without having to remove the safeguards. General Minimum Requirements For Safeguards Prevent Contact Safeguards must prevent employees hands, arms or any other parts of the body from making contact with dangerous moving parts. When proper safeguards are in place, most injuries can be prevented. Be Secure Safeguards should not be easily removed or tampered with. Guards and barriers should be made of durable material that can withstand the conditions of normal use, and they should be firmly secured to the machine or to the floor. Provide Protection From Objects Falling Into The Equipment Safeguards should ensure that no objects can fall into moving parts on the equipment. Even small objects that are dropped into moving parts can become projectiles that shoot out and cause injuries. Create No New Hazards Safeguards must not create new hazards, such as shear points, jagged edges or unfinished surfaces that could cause cuts. The edges of safeguards should be rolled or bolted in a way that eliminates sharp edges. Do Not Cause Interference With Operation Safeguards should not interfere with employees performing their jobs efficiently and comfortably; rather, safeguards should increase efficiency by reducing employees fear of injury. Safeguards that interfere with work will often be removed or otherwise made useless by employees. Page H-13

22 Machine Safeguarding How To Comply General Minimum Requirements For Safeguards (continued) Allow Safe Lubrication And Maintenance Safeguards should not have to be removed for lubrication or maintenance. For example, locating oil reservoirs outside the safeguard, with a line leading to the lubrication point, will reduce the need for employees to remove the safeguard and enter the hazard area. Helping Employees Use Safeguards Make sure that all safeguards are easy to use. The easier it is to work with a safeguard in place, the less likely it will be removed or otherwise made useless. If possible, make sure that maintenance can be performed easily without removing safeguards. Again, this will reduce the chance that the safeguard will be removed and not replaced after maintenance. Because not all machines are alike and because even identical machines are used in different ways in different workplaces, safeguards often are not installed when machines are manufactured. In many cases, safeguards can only be installed after the machines have been delivered to the workplace and their specific functions have been determined (for example, punch presses and press brakes). Thus, machinery must be evaluated to ensure that safeguards are being used. This evaluation should be done when a machine is first put into operation, at regular intervals while it s in use and whenever it s modified for another task. Methods Of Safeguarding There are four major methods of safeguarding, depending on the machine, the workplace, the operation and the hazard: Guards Devices Location/distance Feeding and ejection Guards Guards are barriers that prevent any part of an employee s body from entering a hazardous area on a machine. They are the preferred method of safeguarding because they provide permanent barriers between employees and hazards. Guards should always be made from sturdy material and secured in ways that prevent them from shifting or being removed. There are four main types of guards: Fixed Interlocked Adjustable Self-adjusting Page H-14 Guards should not interfere with performing quality work. Make sure that all guards allow employees to perform tasks safely yet efficiently and effectively.

23 Machine Safeguarding How To Comply Types Of Guards Fixed Guards Fixed guards are permanent parts of machines and contain no moving parts. Also known as enclosure guards, they prevent fingers, hands, other body parts and clothing from reaching through, under, over or around the guards to the point of operation or to other moving parts of the machine. Fixed guards can sometimes be adjusted to fit different tools or material, but after adjustment, they should be attached in a way that prevents them from being moved or detached. To prevent unauthorized removal, fixed guards should be attached with fasteners that cannot be removed without tools. Most fixed guards permit viewing of the point of operation. Interlocked Guards An interlocked guard prevents operation of the control that sets the machine in motion until the guard is in a safe position. When the machine is in motion, the guard cannot be opened, and when the guard is open or removed, the tripping mechanism and/or power automatically shuts off or disengages. As a result, the machine cannot cycle or be started until the guard is put back in place. Effective interlocked guards should do the following: Guard the hazardous area before the machine can be operated. Remain closed until the rotating equipment stops. Be fail safe (that is, if the interlock mechanism fails, the machine cannot be started). Allow inching the machine by remote control, if required. Prevent the machine from restarting immediately or automatically when the guard is replaced. Adjustable Guards Adjustable guards provide flexibility if operations require various sizes of material to be used on one machine. An example of this is a band saw with an adjustable guard to protect the operator from the unused portion of the blade. The guard can be adjusted according to size of the material being used. Self-Adjusting Guards The openings of self-adjusting guards are determined by the movement of the material. As the operator moves the material into the danger area, the guard is pushed away, providing an opening that is only large enough to admit the material. When the material is removed, the guard automatically returns to the rest position. Self-adjusting guards may be constructed of plastic, metal or other substantial material. An example of this type of guard is a table saw with a self-adjusting guard. As the material is pushed through the blade, the guard moves up while staying in contact with the material. Self-adjusting guards don t always provide direct protection from injury. In the case of a radial arm saw or jointer, the self-adjusting guard acts as an awareness device when the blade is in motion. As a result, operators should be trained in the proper precautions to take when using equipment with self-adjusting guards. Page H-15

24 Machine Safeguarding How To Comply Types Of Guards (continued) The following chart compares the advantages and disadvantages of the four types of guards: Guard Type Safeguarding Action Advantages Disadvantages Fixed Provides a barrier. Can be connected to May interfere with visibility. suit many specific Can be limited to specific applications. operations. In-plant construction Must often be removed for is often possible. machine adjustment and Can provide maximum repair, requiring other means protection. of protection for maintenance Usually requires personnel. minimum maintenance. Can be suitable to highproduction, repetitive operations. Interlocked Shuts off or disengages Can provide maximum Requires careful adjustment power and prevents protection. and maintenance. starting of machine Allows access to May be easy to defeat. when guard is open; machine for removing Must be fail safe. should require that the jams without timemachine be stopped consuming removal of before an employee can fixed guards. reach into the danger area. Adjustable Provides a barrier Can be constructed Hands may enter the danger that may be adjusted to suit many specific area, so protection may not be to facilitate a variety applications. complete at all times. of production Can be adjusted to May require frequent operations. admit varying sizes maintenance and adjustment. of materials. May be made ineffective by the operator. May interfere with visibility. Self-Adjusting Provides a barrier Off-the-shelf guards are Don t always provide that moves according often commercially maximum protection. to the size of the available. May interfere with visibility. material entering the May require frequent danger area. maintenance and adjustment. Page H-16

25 Machine Safeguarding How To Comply Guard Openings Guards may have openings for the following reasons: To insert material for processing To allow access for inspection or lubrication To monitor machine action However, the larger the opening, the further an employee can reach into it. This may pose a hazard if the guard is too close to the point of operation. In material processing, the challenge is to have an opening that s large enough to pass the material through yet will be safe for employees. To ensure safety, the larger the opening, the further from the point of operation the guard must be. The following table indicates the distance a guard must be from the point of operation for each of several size openings: Distance Of Opening Maximum Width From The Danger Line (inches) Of Opening (inches) 1/2 to 1-1/2 1/4 1-1/2 to 2-1/2 3/8 2-1/2 to 3-1/2 1/2 3-1/2 to 5-1/2 5/8 5-1/2 to 6-1/2 3/4 6-1/2 to 7-1/2 7/8 7-1/2 to 12-1/2 1-1/4 12-1/2 to 15-1/2 1-1/2 15-1/2 to 17-1/2 1-7/8 17-1/2 to 31-1/2 2-1/8 For distances over 31-1/2 inches, use 6 inches as the maximum opening. See the diagram in OSHA Standard CFR , paragraph f(4). Some machines (such as press brakes and notchers) must be completely closed to operate. As such, they should have guard openings of 1/4 when accessible by the operator for feeding material; the operator should then be required to move away from the point of operation (through the use of two-hand controls, light curtains or other devices) before the full stroke can be started. If a machine has a guard opening of 1/4 or less, controls aren t necessary because the operator s fingers cannot enter the point of operation. Page H-17

26 Machine Safeguarding How To Comply Devices In situations in which adequate guards can t be provided, point-of-operation devices should be used instead. These devices may perform any of several possible functions: Stopping the machine if any part of the body enters the point of operation Restraining or withdrawing the operator s hands from the point of operation when the machine is operating Requiring the operator to use both hands on the machine controls, keeping both hands and the body away from the point of operation Providing a barrier synchronized with the operating cycle of the machine to prevent entry into the point of operation during the hazardous part of the cycle These are the main types of devices: Presence sensing Pullback Restraint Safety-trip control Two-hand control Two-hand trip Gates Pressure mats The point of operation and other hazardous parts of machines are sometimes protected by shields. Shields are intended to help protect against flying chips and sparks and to help prevent inadvertent operator contact with moving parts. They do not assure as high a level of protection as a guard but they can still be effective in preventing injuries. Types Of Devices Presence-Sensing Devices A presence-sensing device detects the presence of the operator s hands or fingers within the point of operation. If hands or fingers are detected, the machine will not operate or will stop quickly enough to prevent injury. Presence-sensing devices have three methods of operation: Photoelectric (optical): This method uses a system of light sources and controls that can interrupt the machine s operating cycle. If the light field is broken, the machine will stop and not cycle. Devices that operate in this way should only be used on machines that can be stopped before an employee can reach into the point of operation. Radio frequency (capacitance): This method uses a radio beam that s part of the machine control circuit. When the capacitance field is broken, the machine will stop or will not activate. Like photoelectric devices, devices that operate by radio frequency should only be used on machines that can be stopped before an employee can reach into the point of operation. Electromechanical: This device has a probe or contact bar that descends to a predetermined distance when the operator initiates the machine cycle. If an obstruction prevents the probe or bar from fully descending, the control circuit will not actuate the machine cycle. Page H-18

27 Machine Safeguarding How To Comply Types Of Devices (continued) Pullback Devices A pullback device has a series of cables attached to the operator s hands, wrists and/or arms. This type of device is used primarily on machines with a stroking action. When the slide/ram is up, the operator is allowed access to the point of operation. When the slide/ram begins to come down, a mechanical linkage automatically pulls the operator s hands away from the point of operation. Restraint Devices A restraint device (also known as a holdout) uses cables or straps, one end of which is attached to the operator s hands and the other to a fixed point. The cables or straps are adjusted to let the operator s hands travel within a predetermined safe area. There is no extending or retracting action involved, so hand-feeding tools are often necessary if the operation involves placing material into the point of operation. Safety-Trip Control Devices Safety-trip control devices provide a quick means of stopping machines in emergency situations. There are a number of different types of safety-trip control devices, including these: Pressure-sensitive body bars: A bar is located between the operator and the point of operation; when depressed, the bar will deactivate the machine. If an employee trips, loses balance or is drawn into the machine, applying pressure to the bar will stop the operation. Safety triprods: A rod runs across the front of a machine; when pressed by hand, the rod deactivates the machine. Because it must be pushed during an emergency operation, the positioning of the triprod is critical. Safety tripwires: A cable is located around the perimeter of or near the point of operation. The operator must be able to reach the cable with either hand to stop the machine. Two-Hand Control Devices A two-hand control requires contact pressure by both of the operator s hands to activate the machine. The operator s hands are required to be at a safe location (on the control buttons) and at a safe distance from the point of operation while the machine completes its cycle. Two-hand controls should always be equipped with anti-tiedown devices or circuits that prevent operators from tying down, blocking or otherwise defeating one control to allow for one-hand operation. Two-Hand Trip Devices Similar to the two-hand control, the two-hand trip requires pressure on both the control buttons to activate the machine cycle. However, once the machine has started a cycle, the hands can be removed from the control. This device is usually used with machines that are equipped with fullrevolution clutches. The trips must be placed far enough from the point of operation to make it impossible for the operator to move his or her hands from the trip controls into the point of operation before the first half of the cycle (downstroke) is completed. Two-hand control and two-hand trip devices only protect employees if there is a set of controls for each employee working at the machine. If machine operation requires placing hands into the point of operation, employees must not be allowed to do so while another employee activates the two-hand control or two-hand trip. This is critical for normal operations, machine adjustment and machine set-up. Gates A gate is a movable barrier that protects the operator at the point of operation before the machine cycle can be started. Gates are often designed to be operated with each machine cycle. If the gate isn t completely closed, the machine won t activate. Gates can be used as parts of perimeter safeguarding systems (systems that prohibit entry to the area around a machine). In these situations, gates provide protection both to operators and to pedestrian traffic. Page H-19

28 Machine Safeguarding How To Comply Types Of Devices (continued) Pressure Mats A pressure mat is a device that s designed to prevent machine operation if pressure is detected on it. For instance, if an operator steps on the mat, the machine will not operate or will stop. Pressure mats are placed so that hazard areas cannot be approached without stepping on the mats. Pressure mats can also be used to prevent entry to areas around automated equipment. OSHA requires that a presence-sensing device or two-hand control or trip be located far enough away from the point of operation to allow the machine to stop before an operator s hand can come into contact with the point of operation. The minimum safety distance is determined by multiplying the stopping time of the machine by the constant hand speed of 63 inches per second. For example, if a machine has a stopping time of 1/2 second, the guarding device must be located at least 31-1/2 inches from the point of operation. The following chart compares the advantages and disadvantages of the various types of devices: Device Type Safeguarding Action Advantages Disadvantages Photoelectric Machine will not start Can allow freer Does not protect against (Optical) cycling when the light movement for operator. mechanical failure. field is interrupted. May require frequent When the light field is alignment and calibration. broken by any part of Limited to machines that the operator s body can be stopped quickly. during the cycling process, immediate machine braking is activated. Radio Machine cycling will Can allow freer Does not protect against Frequency not start when the movement mechanical failure. (Capacitance) capacitance field is for the operator. Antenna sensitivity must interrupted. be properly adjusted. When the capacitance Limited to machines that field is disturbed by can be stopped quickly. any part of the operator s body during the cycling process, immediate machine braking is activated. Electro- Contact bar or Can allow access at the Contact bar or probe must mechanical probe travels a point of operation. be properly adjusted for predetermined distance each application, and the between the operator adjustment must be and the point of operation. properly maintained. Interruption of this movement prevents starting the machine cycle. Page H-20