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Occupational Safety and Health contains procedures commonly practiced in industry and the trade. Specific procedures vary with each task and must be performed by a qualified person. For maximum safety, always refer to specific manufacturer recommendations, insurance regulations, specific job site and plant procedures, applicable federal, state, and local regulations, and any authority having jurisdiction. The material contained herein is intended to be an educational resource for the user. American Technical Publishers, Inc. assumes no responsibility or liability in connection with this material or its use by any individual or organization.
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The authors and publisher are grateful for the photographs, technical information, and assistance provided by the following companies and organizations: APAâ€”The Engineered Wood Association Baldor Motors and Drives Ballymore Company, Inc. Bureau of Labor Statistics Chicago Pneumatic Cooper Bussmann Cooper Wiring Devices Eagle Manufacturing Company ESAB Welding & Cutting Products Federal Highway Administration (FHWA) Fluke Corporation Harrington Hoists, Inc. Hobart Welders Ingersoll-Rand Material Handling Jackson Safety, Inc. Lift-All Company, Inc. The Lincoln Electric Company Master Lock Company LLC Miller Electric Manufacturing Company
Technical review provided by the following individuals: Dave McDonald Industrial Automation Systems Instructor Integrity Integration Resources Georgi Popov, PhD, QEP Associate Professor Safety Science Programs University of Central Missouri Eileen Mason, PhD, CIH, CSP Formerly with Murray State University Dept. of Occupational Safety and Health
Milwaukee Electric Tool Corp. National Oceanic and Atmospheric Administration (NOAA), National Weather Service Nederman, Inc. North by Honeywell OSHA Panduit Corp. Saylor-Beall Manufacturing Company Sellstrom Manufacturing Co. Shermco Industries The Sinco Group, Inc. Skil Corporation Snorkel The Stanley Works STIHL Inc. Tower Manufacturing Corporation USDA NRCS W.W. Grainger, Inc. Werner Ladder Co.
Overview of Occupational Safety and Health_______________ 1
The Occupational Safety and Health Profession___________ 17
Safety and Occupational Health Program Development___ 33
Laws, Regulations, and Standards______________________ 53
Hazard Recognition____________________________________ 79
Occupational Injury and Illness in the United States • Safety • Hazards • Unsafe Acts • Preventing Accidents • Safety Compliance • Hazards and Risk • Controlling Hazards and Risk • Occupational Safety and Health Program Overview
Occupational Safety and Health Managers • Occupational Safety and Health Specialists • Industrial Hygienists • Safety Engineers • Occupational Safety and Health Technicians • Ergonomists • Product Safety Engineers • Health Physicists • Education • Certification • Ethics • Personal Attributes • Advancement • Employment • Work Environment • Salary • Skills • Job Duites
Safety and Occupational Health Program Guidelines • Safety and Occupational Health Program Elements • Management Leadership • Employee Involvement • Work Site Analyses • Hazard Prevention and Controls • Safety and Health Training • Strategies Used in Safety and Occupational Health Programs • Behavior-Based Safety • Integrated Safety Management • Six Sigma • Risk Management • Voluntary Protection Program
The US Federal Government • The Origins of Safety Laws • The Occupational Safety and Health Act of 1970 • Occupational Safety and Health Review Commission • National Institute for Occupational Safety and Health • OSHA Standards and Regulations • OSHA Inspections • Mining Safety and Health Laws • Federal Aviation Administration • Federal Highway Administration • Federal Railroad Administration • Maritime Administration • Nuclear Regulatory Commission • Food and Drug Administration • Environmental Protection Agency • Consensus Safety Standards • Independent Safety Boards
Workplace Hazards • Hazard Recognition Methods • Safety Inspections • Employee Hazard Reporting • Hazard Analyses
Personal Protective Equipment_________________________ 95
Walking and Working Surfaces_________________________123
Ladders and Scaffolds_________________________________143
Hand and Portable Power Tools________________________169
Personal Protective Equipment • Regulations and Standards for PPE • Exposure Pathways • Assessing Hazards • Chemical Eye Hazards • Radiant Energy • Noise • Biological Agents • Eye Protection • Protective Clothing • Head Protection • Foot Protection • Hand Protection • Hearing Protection • Respiratory Protection • Electrical Protective Equipment • PPE Programs • Selecting PPE • Training Employees on the Proper Use of PPE
Regulations and Standards for Walking and Working Surfaces • Slip Hazards • Trip Hazards • Fall Hazards • Hazard Controls for Walking and Working Surfaces • General Housekeeping • Maintaining Safe Aisles • Stairway Safety • Ramp Safety • Hazard Surveillance • Floor Surface Selection • Floor Surface Treatments • Floor Mats • Slip-Resistant Footwear • Guardrails, Covers, Gates, and Doors • Fall Protection • Fall-Protection Programs • Floor Loading Safety • Stationary Vehicle Safety • Education and Training
Portable Ladders • Fixed Ladders • Ladder Components and Accessories • Ladder Material • Pole Scaffolds • Sectional Metal-Framed Scaffolds • Suspension Scaffolds • Regulations and Standards for Ladders and Scaffolds • Falls • Falling Objects • Contact with Electricity • Hazard Controls for Ladders • Ladder Positioning and Climbing Procedures • Ladder Inspection • Ladder Maintenance and Storage • Hazard Controls for Fixed Ladders • Hazard Controls for Scaffolds
Regulations and Standards for Hand Tools, Power Tools, and Related Equipment • Hand Tool and Portable Power Tool Hazards • Electrical Shock • Trips, Slips, and Falls • Falling Hazards • Health Hazards • Hazard Controls • Selecting the Right Tool • Using Proper PPE • Following Operating Procedures • Inspecting Tools • Maintaining Tools • Storing Tools Properly • Maintaining Clean Work Areas • Hazard Controls for Specific Tools • Circular Saws • Reciprocating Saws • Chain Saws • Power Drills • Pneumatic Tools • Powder-Actuated Tools
10 Welding and Allied Processes__________________________195
Regulations and Standards for Welding and Allied Processes • Hazards in Welding and Allied Processes • Fumes • Gases • Burns • Decomposition Products • Ergonomic Stressors • Hazard Controls for Welding and Allied Processes • Ventilation • PPE for Welding and Allied Processes • Fire Prevention • Ergonomics • Cleaning Hazardous Substance Containers • Welding and Allied Processes in Confined Spaces • Welding and Cutting Equipment
Regulations and Standards for Machine Safeguarding • Machine Hazards • Rotating Motions • Reciprocating Motions • Transverse Motions • Cutting Actions • Punching Actions • Shearing Actions • Bending Actions • Hazard Control • Requirements for Mechanical Safeguards • Machine Safeguarding Methods • Lockout/Tagout
12 Material Handling_____________________________________ 237
Regulations and Standards for Material Handling • Manual Material Handling Hazards • Mechanical Material Handling Hazards • Powered Industrial Trucks • Cranes and Derricks • Hoists • Manually Operated Hoists • Power-Operated Hoists • Slings • Rigging • Manual Material Handling Hazard Controls • Mechanical Material Handling Hazard Controls • Lifting Loads
13 Control of Hazardous Energy__________________________ 275
Regulations and Standards for the Control of Hazardous Energy • Hazardous Energy in the Workplace • Forms of Energy • Potentially Hazardous Energy Combinations • Interconnected Machines or Equipment • Controls for Hazardous Energy • Identifying Energy Sources • Deenergizing Equipment • Dissipating Potential (Stored) Energy • Lockout/Tagout • Hazardous Energy Control Programs • Energy Control Procedures • Employee Training • Periodic Inspections
14 Confined Spaces_____________________________________ 293
Types of Confined Spaces • Regulations and Standards for Confined Spaces • Confined Space Hazards • Engulfment Hazards • Configuration Hazards • Hazardous Atmospheres • Hazard Controls for Confined Spaces • PermitRequired Confined Space Entry Programs • Identifying PRCSs and Evaluating Hazards • Deciding if Workers May Enter a Confined Space • Eliminating or Controlling Hazards in Confined Spaces • Establishing Entry Procedures and Preparing Entry Permits • Training Employees on Entry Operations and Responsibilities • Emergency Plans
15 Electrical Safety_______________________________________321
Regulations and Standards for Electrical Safety • Electrical Hazards in the Workplace • Hazardous Locations • Electrical Shock • Arc Flash • Arc Blast • Electrical Hazard Controls • Electrical Hazard Control Procedures • Electrical Hazard Control Policies • Inspection and Audits
16 Hazardous Materials Management_____________________ 345
Regulations and Standards for Hazardous Materials • Process Safety Management • Medical Surveillance • Hazardous Waste Operations and Emergency Response • Hazard Communication • Occupational Exposure to Hazardous Chemicals in Laboratories • Health Hazards Involving Hazardous Materials • Toxins • Physical Hazards Involving Hazardous Materials • Chemical Safety and Life Cycle Management Programs
17 Process Safety Management__________________________
Regulations and Standards for Process Safety Management • Highly Hazardous Chemicals • Toxic Chemicals • Reactive Chemicals • Flammable Chemicals • Explosive Chemicals • Hazard Controls for Highly Hazardous Chemicals • Process Safety Management Programs
18 Fire Prevention_______________________________________ 399
Regulations and Standards for Fire • Fuel • Oxygen • Heat • Chemical Reaction • Fire Hazards • Fire Hazard Controls • Identifying Hazards • Engineering Controls • Fire-Prevention Plans • Fire-Protection Strategies • Operation Controls • Extinguishing Fires • Firefighting
19 Motor Vehicle Transportation Safety_____________________ 417
Regulations and Standards for Transportation and Safety • ISO 39001, Road Traffic Safety Management Systems – Requirements with Guidance for Use • Environmental Transportation Hazards • Mechanical Transportation Hazards • Driver Errors • Hazardous-Material Cargo Releases • Roadwork Zones • Transportation Hazard Controls • Policies • Drug and Alcohol Testing • Compliance, Safety, Accountability • Sample Transportation Safety Management Program
20 Occupational Health__________________________________ 437
Regulations and Standards for Occupational Health • Hazard Awareness • Exposure Levels • Health Hazard Assessments • Exposure Assessments • Occupational Health Hazards • Occupational Health Programs • Exposure Control • Occupational Health Care and Medical Provisions
21 Emergency Planning__________________________________ 457
Regulations and Standards for Emergency Planning • Identifying Workplace Hazards • Vulnerability Assessments • Quantification of Vulnerability Assessments • Anticipation, Identification, and Control of Hazards • Emergency Management
22 Accident Investigation and Reporting___________________ 475
Accident Investigation and Reporting • Regulations and Standards for Accident Investigation and Reporting • Accidents • Human Factors • Mechanical Factors • Environmental Factors • Investigation Process
Learner Resources___________________________________________ • Quick Quizzes
• Safety Forms
• Illustrated Glossary
• Media Library
• Flash Cards
Occupational Safety and Health provides an overview of potential workplace hazards, necessary safety practices, and how various industrial processes need to be managed in order to maintain a safe workplace. This textbook is designed for use in introductory safety courses and by professionals who want to advance in the field. It is also a helpful reference for managers, technicians, instructors, safety committees, and others who are responsible for preparing safety training courses, presentations, and toolbox talks. Appropriate safety regulations and laws, hazard recognition, personal protective equipment, and public safety are addressed. Case studies are included to demonstrate how safety practices can be applied to real-world scenarios. Photographs and illustrations are used throughout the book to show examples, detail procedures, and supplement topics. Quick reference (QR) codes located throughout the book provide online access to related information, including safety regulations and forms.
Photographs depict safety applications commonly found in the workplace.
QR Codes throughout the chapter enable quick access to online safety resources. Safety Advisories provide related safety information.
Chapter Summaries at the end of each chapter provide a brief description of main topics covered.
Detailed Illustrations depict major topics and concepts.
Case Studies demonstrate how safety practices can be applied to real-world scenarios.
Key Terms at the end of each chapter reinforce comprehension.
Occupational Safety and Health also includes access to learner resources that reinforce textbook content and enhance learning. These online learner resources can be accessed using either of the following methods: • Key ATPeResources.com/QuickLinks into a web browser and enter QuickLink™ code 674900. • Use a Quick Response (QR) reader app to scan the QR code with a mobile device.
Digital Learner Resources ATPeResources.com/QuickLinks Access Code: 674900
Occupational Safety and Health includes access to online learner resources that reinforce textbook content and enhance learning. These learner resources include the following: • Quick Quizzes® that provide interactive questions for each chapter, with embedded links to highlighted content within the textbook and to the Illustrated Glossary • Illustrated Glossary that serves as a helpful reference to commonly used terms, with selected terms linked to textbook illustrations • Flash Cards that provide a self-study/review of common terms and their definitions • Safety Forms that include common forms used by safety personnel that can be printed for use in the field • Media Library that consists of videos and animations that reinforce textbook content • ATPeResources.com, which provides access to additional online resources that support continued learning
Objectives • Describe the difference between hand tools and portable power tools. • Identify the safety standards that apply to hand tools and portable power tools. • Describe the hazards associated with using hand tools and portable power tools. • List the key elements that determine the correct tool for a task.
• List the hazard controls that are commonly used with most hand tools, portable power tools, and other equipment. • Identify the different types of hand tools and portable power tools. • Describe the basic components of pneumatic tools. • List the safety precautions that should be used when operating powder-actuated tools.
Almost every industry has workers who use hand and portable power tools and other handheld equipment. OSHA and other industry standards provide requirements, guidelines, and best practices for using hand and portable power tools and other handheld equipment. Tool design, tool use, tool maintenance, and consideration of the environment contribute to safe work procedures and a safe work environment. Hazard controls should be implemented when using common hand and portable power tools. Specific hazard controls are applied to unique hazards of specialized individual hand and portable power tools.
HAND TOOLS A hand tool is any of a variety of tools that are used manually. Hand tools can be used for measuring, fastening, prying, sawing, cutting, clamping, boring, smoothing, and other purposes. Hand tools include hacksaws, knives, wrenches, files, and screwdrivers, among others. See Figure 9-1.
PORTABLE POWER TOOLS A portable power tool is any of a variety of tools that are easily moved and powered by electricity, pneumatic or hydraulic power, liquid fuel, or an explosive charge. Tasks that are usually performed more efficiently with the use of power tools include drilling, cutting, and fastening. Common power tools include drills, circular saws, reciprocating saws, pneumatic nailers, hydraulic jacks, and powder-actuated tools.
Many electrically powered tools can operate with either a direct current (DC) power source, such as a battery, or an alternating current (AC) power source. Power tools that operate with a DC power source are also known as cordless power tools. See Figure 9-2. Cordless power tools are convenient because they are easily transported, they do not rely on an external power source, and they pose less risk of accidents from trips and falls over a power cord. However, cordless power tools are usually more expensive and do not provide as much power, which may be a disadvantage when working on large-scale projects. A pneumatic tool is any of a variety of tools powered by compressed air. A hydraulic tool is any of a variety of tools powered by compressed liquid. Common types of pneumatic and hydraulic tools that are used in industry include buffers, nailing and stapling guns, grinders, drills, jack hammers, chipping hammers, riveting guns, sanders, and wrenches. 169
170 OCCUPATIONAL SAFETY AND HEALTH
Figure 9-1. Various hand tools are used by employees for the maintenance, troubleshooting, and installation of different types of equipment.
A powder-actuated tool is any of a variety of tools powered by a controlled explosion. There are different styles of powder-actuated tools, typically used to shoot fasteners or anchors into block walls, concrete slabs, or steel.
Cordless Power Tools
REGULATIONS AND STANDARDS FOR HAND TOOLS, POWER TOOLS, AND RELATED EQUIPMENT BATTERY
CORDLESS BAND SAW
Both Occupational Safety and Health Administration (OSHA) and industry consensus standards apply to hand and portable power tools and other handheld equipment. OSHA regulations specify the regulatory requirements for the safe use of tools. Industry consensus standards are guidelines that include regulatory standards and best practices. Many of the OSHA regulations are derived from industry consensus standards. SAFETY ADviSORY
Figure 9-2. Cordless power tools are powered by DC power sources (batteries).
The manufacturerâ€™s operating and maintenance instructions provide valuable information about the use, hazards, and maintenance of a power tool.
Chapter 9 — Hand and Portable Power Tools 171
OSHA Regulations for Hand Tools, Power Tools, and Related Equipment OSHA standards make the employer responsible for the safe condition of tools and equipment used by employees. This includes tools and equipment employees bring to the job. In general industry, OSHA addresses hand and portable power tools in OSHA 1910 Subpart P — Hand and Portable Powered Tools and Other Hand-Held Equipment. This section also provides requirements for safety guards on portable power tools. On/off switches, cutoff switches, and controls are used as safeguards to protect workers from hazards that may occur while using power tools. OSHA 1926 Subpart I — Tools - Hand and Power covers hand and power tools for the construction industry. See Figure 9-3. Additionally, OSHA 1910 Subpart R — Special Industries addresses tools within the logging industry. OSHA 1910 Subpart T — Commercial Diving Operations addresses tools used during diving operations.
Hammer drills are used by workers to drill holes in concrete.
All portable electric tools should be grounded or double insulated because they can be used outdoors and in various wet environments. A tool that is grounded has a three-prong plug. Tools that are double insulated are labeled as such on the tool. See Figure 9-4. Specific portable power tools, including pneumatic power tools and hoses, portable abrasive wheels, powder-actuated fastening tools, power lawn mowers, jacks, and abrasive blast cleaning nozzles, have special OSHA requirements.
OSHA Regulations for Hand and Power Tools and Equipment • 1901—Procedures for State Agreements • 1902—State Plans for the Development and Enforcement of State Standards • 1903—Inspections, Citations, and Proposed Penalties • 1904—Recording and Reporting Occupational Injuries and Illness • 1905—Rules of Practice • 1906—Administration Witness and Documentations in Private Litigation • 1908—Consultation Agreements • 1910—Occupational Safety and Health Standards (Subpart P—Hand and Portable Powered Tools and Other Hand-Held Equipment) • 1911—Rules of Procedure for Promulgating, Modifying or Revoking OSHA Standards • 1912—Advisory Committees on Standards • 1912A—National Advisory Committee on OSHA • 1913—Rules Concerning OSHA Access to Employee Medical Records • 1915—Occup. Safety and Health Standards for Shipyard Employment • 1917—Marine Terminals • 1918—Safety and Health Regulations for Longshoring • 1919—Gear Certification • 1920—Procedure for Variations under Longshoremen’s Act • 1921—Rules of Practice in Enforcement under Section 41 of Longshoremen’s Act • 1922—Investigational Hearings under Section 41 of the Longshoremen’s and Harbor Workers’ Compensation Act • 1924—Safety Standards Applicable to Workshops and Rehab. Facilities • 1925—Safety and Health Standards for Federal Service Contracts • 1926—Safety and Health Regulations for Construction (Subpart I—Tools - Hand and Power) • 1927—Reserved
Figure 9-3. OSHA regulations that cover hand and portable power tools are listed under OSHA 1910 Subpart P — Hand and Portable Powered Tools and Other Hand-Held Equipment and OSHA 1926 Subpart I — Tools - Hand and Power.
OSHA Regulations for Hand and Portable Power Tools and Other Hand-Held Equipment Access Code: 674031
172 OCCUPATIONAL SAFETY AND HEALTH
Double-Insulated Label DOUBLEINSULATED LABEL
Figure 9-4. A double-insulated portable electric tool can be easily identiďŹ ed by a marking on the label.
Other Standards for Hand Tools, Power Tools, and Related Equipment Virtually every type of hand and portable power tool has a consensus standard that addresses tool design, material, and manufacturing specifications. Many standards-producing organizations develop the technical standards for specific organizations and industries. For example, the American Society of Mechanical Engineers (ASME) develops standards for hand tools for the American National Standards Institute (ANSI). Their standards are in the ANSI/ASME B107 series. SAE International, formerly the Society of Automotive Engineers, develops standards for hand and portable power tools for the aerospace, automotive, and commercial vehicle industries. The technical standards complement and exceed the general industry regulatory requirements in focusing on the tool design and use in a specific industry.
HAND TOOL AND PORTABLE POWER TOOL HAZARDS Identifying the hazards of using hand tools and portable power tools will help safety professionals design an effective
safety system and safe working environment. Hazards of using hand tools generally result from poor tool design, inadequate maintenance of the tool, and improper use of the tool. Workers should be able to use hand tools comfortably and perform tasks efficiently without concern that the hand tool could cause or contribute to an injury. It is not uncommon for workers to get hand muscle cramps because tools are awkward or not of an adequate weight for the task. Another typical hazard is using tools that are splintered, chipped, dull, or otherwise damaged. Tools that are not maintained will eventually fail, sometimes causing an injury to the employee or bystanders. Hazards can also be caused when a worker uses a tool improperly. The common safety advice is to use the right tool for the job. Common hazards associated with power tools include flying debris, cuts and abrasions, electrical shock, trips, slips, falls, falling tools, and health hazards.
Flying Debris Both hand tools and portable power tools can produce flying debris that can get in eyes or puncture the skin. For example, drilling metal or wood can produce fine filings or particulates that can become airborne, potentially entering the workerâ€™s breathing zone, or embedded in soft tissue. These situations pose hazards to the operator as well as others in the area.
Cuts and Abrasions Any hand tool with a sharp edge can penetrate the skin. Improper handling of a tool or failure to secure a workpiece in place may cause the tool to slip and injure the user. For example, using a screwdriver on an unstable workpiece or using the wrong-sized screwdriver can result in tool slippage and possible injury. See Figure 9-5. Dull blades on a power saw may cause the saw to kick-back and cause injury. Accidental starting of power tools, such as saws or grinders, can lead to cuts or abrasions.
Chapter 9 â€” Hand and Portable Power Tools 173
Cuts and Abrasions
SCREWDRIVER DIRECTION OF FORCE
SCREWDRIVER DIRECTION OF FORCE
WORKPIECE HELD ON LEVEL SURFACE
WORKPIECE HELD IN UNSTABLE POSITION
CORRECT TOOL USE
INCORRECT TOOL USE
Figure 9-5. Improper hand tool use can result in puncture wounds, cuts, or abrasions.
Electrical Shock Electrical shock is a hazard associated with tools powered by electricity. All electric corded tools, equipment, or devices must isolate electrical energy from contact with the user with either ground-fault circuit interrupter (GFCI) outlets or other acceptable means of grounding, unless the tool is double insulated to ensure worker safety. A GFCI protects against electrical shock by detecting an imbalance of current in the normal conductor pathway and then quickly opening the circuit, thus preventing electrical current from reaching the tool and user. The most common type of GFCI outlet used on job sites or at outdoor locations is the portable GFCI type. See Figure 9-6. Portable GFCIs should be inspected and tested before each use. GFCIs have built-in test circuits to ensure that the ground-fault protection is operational. If GFCIs are not available, an acceptable means of grounding must be established to prevent electrical shock. In order to be grounded, a power tool must have a threeconductor cord with a three-prong plug that fits into a grounded outlet. See Figure 9-7. It is unsafe to remove the third prong on a power tool because that eliminates the protective grounding capability that protects the user from electrical shock. Tools must
be used as designed and intended and must not be modified for a perceived temporary convenience. If it is necessary to use a temporary extension cord, the extension cord must have the same protective grounding properties as the tool. An extension cord is simply an extension of the length of cord attached to the tool.
Portable Ground-Fault Circuit Interrupters (GFCIs) RECEPTACLE OUTLET COVERS TEST/RESET BUTTONS
Tower Manufacturing Corporation
Figure 9-6. All electric corded tools, equipment, or devices must use either GFCI outlets or other acceptable means of grounding unless the tool is double insulated.
OCCUPATIONAL SAFETY AND HEALTH
NONLOCKING FOR 120 V TOOLS; ACCEPTABLE FOR INDOOR WORK
LOCKING FOR 120 V TOOLS; RECOMMENDED FOR OUTDOOR WORK
LOCKING FOR 240 V TOOLS AND EQUIPMENT
Figure 9-7. Various conﬁgurations of approved grounded outlets are available for electric power tools and equipment.
Double-insulated tools do not require a grounding system for safe operation. The electric motor components are covered by non-conductive insulation that prevents current from reaching the metal surface of the tool and prevents the tool from becoming energized. A properly grounded or doubleinsulated corded tool can still be dangerous under wet conditions since water is an electrical conductor. SAFETY ADviSORY An ergonomic assessment of a tool should include consideration of the weight of the tool; the handle comfort, fit, diameter, length, texture, and shape with respect to the user; and ease in using the controls.
Trips, Slips, and Falls Stable footing and balance are important when using hand tools. This is especially important when electrical power tools are used because they are more powerful than manual hand tools. Other hazards include power cords that create tripping hazards, tangled cords, and slip-causing debris due to poor housekeeping or inefficient work area design.
Falling Hazards Portable tools are commonly used while working on ladders or scaffolding. This presents two types of hazards. One hazard is the risk of the operator losing balance and falling
from an elevated height. The other hazard is the risk of the operator dropping the tool on themselves or someone in the area.
Health Hazards Awkward body positions and constant strain on muscles from the operation or use of tools that are not designed for the task can lead to repetitive motion injuries such as carpal tunnel syndrome, tendinitis, or muscle strain. These injuries usually do not happen because of a single event, such as a fall or electrical shock. Instead, they result from repetitive movements that are performed over time or for a long period of time, which may result in damage to muscles, tendons, nerves, ligaments, joints, cartilage, spinal discs, or blood vessels. See Figure 9-8. Symptoms may not appear immediately because they develop over weeks, months, or years. Symptoms that may indicate a health problem due to awkward body positions or repetitive movements include the following: • tingling • swelling in the joints • decreased ability to move • decreased grip strength • pain from movement, pressure, or exposure to cold or vibration • continual muscle fatigue • sore muscles • numbness • change in skin color of the hands or fingertips
Chapter 9 â€” Hand and Portable Power Tools 175
Health Hazards from Tools
APAâ€”The Engineered Wood Association
Figure 9-8. Repetitive movements that are performed over time or for a long period of time can lead to repetitive motion injuries such as carpal tunnel syndrome, tendinitis, or muscle strain.
Exposure to airborne particulates, chemicals, or dust can also lead to acute and chronic health problems. Grinding and sawing tools can produce excessively dusty conditions and hazardous atmospheres. Appropriate hazard controls must be used to control excessive dust and exposure to asbestos, silica, hexavalent chromium, and other hazardous particles. Many portable power tools produce noise that requires the operators and others around them to wear hearing protection when in use. Operators and workers around them should have a hearing conservation program in place.
safely. When deciding which tool to use for a job, it is important to consider the work being performed, tool ergonomics, and the workspace. Tools should be used for their intended purpose and within their design limitations. Different types of tools are designed for different purposes. Operating procedures provided by the manufacturer can be used to determine tool function and proper use. Any additional accessories must be appropriate for the task. For example, when using an electric angle grinder to grind material, make sure a grinding wheel is attached and not a cut-off wheel. Comfort should be considered when selecting the right tool. A tool should fit comfortably in the userâ€™s hand and be used in a comfortable position. See Figure 9-9. Large tools and heavy tools can pose ergonomic hazards for workers who must use, lift, or carry them for long periods of time. Hand strain can be controlled by varying tasks so the same tool is not used all day. National Institute for Occupational Safety and Health (NIOSH) Publication No. 2004-164, A Guide to Selecting Non-Powered Hand Tools, describes information on evaluating tools to prevent repetitive motion injuries.
HAZARD CONTROLS Most hand tools and portable power tools have similar hazard controls. These controls include selecting the right tool for the job, using appropriate PPE, following proper operating procedures, tool inspection procedures, tool maintenance procedures, tool storage procedures, and maintaining a clean work area. These types of hazard controls should be included in a job hazard analysis (JHA) and standard operating procedures.
Selecting the Right Tool The best tool for a job is one that is designed to do the job efficiently, comfortably, and
Figure 9-9. Hand and power tools have different designs to make certain tasks more comfortable.
OCCUPATIONAL SAFETY AND HEALTH
The workspace should be considered when selecting the right tool. There must be adequate space to use the tool. Employees must be aware of overhead and underground power lines, electrical circuits, water pipes, and other mechanical hazards in the area. They should pay particular attention to below the work surface or where hazards can be hidden from the operator’s view. The workspace environment may also determine the appropriate tool for the job. For example, using sparking tools in a flammable atmosphere can cause fires resulting in burns and property damage. Where this hazard exists, spark-resistant tools made from brass, plastic, aluminum, or wood should be used. Non-sparking, spark-resistant, or spark-proof tools are names given to tools made of metals such as brass, bronze, Monel® metal (copper-nickel alloy), copper-aluminum alloys (aluminum bronze), copper-beryllium alloys (beryllium bronze), and titanium. Non-sparking metals have less tensile strength than other tools. Tensile strength is the maximum amount of force that can be used to pull a material before it breaks. A lower tensile strength means the metal has less strength or resistance to breaking apart. It also means that these tools are softer and wear down more quickly than ordinary steel tools.
Using Proper PPE The type of hand tool used for a task is a factor in determining the PPE used. Many power tools have rotating or reciprocating parts that can snag clothing, hair, or jewelry. Work clothing should be snug but allow unrestricted movement. See Figure 9-10. Loose or baggy clothing can get caught in moving parts. Jewelry and other accessories should not be worn because of the potential to get hooked or caught. Workers should pull hair back in a band or a cap to keep it from getting caught in moving parts. Rotating pieces of equipment such as drills or drill presses are especially dangerous around loose, long hair.
PPE for Hand Tools
Figure 9-10. Work clothing should be snug to prevent items from getting caught in moving tool parts.
Easily combustible work clothing should not be worn, especially when using tools that produce sparks or flames. Synthetic clothing can ignite or easily melt, which can result in severe burns. To prevent burns, employees should wear clothing such as coveralls, high-top shoes, leather aprons, and leather gloves. Pockets should be empty of combustible material, and pants and sleeves should be cuffless to prevent hot objects from lodging in the cuffs. If there is an arc flash or arc blast hazard, NFPA 70E®, Standard for Electrical Safety in the Workplace®, should be followed because there is not a specific OSHA regulatory standard for arc flash safety. Industrial-quality eye protection must be worn when using hand and portable power tools. Industrial quality means that the eye protection meets the requirements of OSHA 1910.133 — Eye and Face Protection and ANSI Z87.1, American National Standard Practice for Occupational and Educational
Chapter 9 — Hand and Portable Power Tools 177
Eye and Face Protection. There are several types of eye protection to choose from depending on the hazards involved with the work. For example, when working around chemicals, chemical safety glasses that have top and side shields on the lenses should be used to protect the eyes from inadvertent splashes or droplets that can cause eye damage or blindness. Safety glasses or goggles with side shields are generally worn when work involves the potential for flying particles of glass, wood, metal, or other materials. In some jobs where there are various hazards, safety glasses should be worn in addition to face shields. Portable power tools can produce excessive noise levels. The tool operator and employees around them are required to wear the proper hearing protection when the tool is in use or where “HEARING PROTECTION REQUIRED” signs are posted. Respirators may be needed when operating tools that produce excessively dusty conditions. For example, when performing vehicle brake work, a high-efficiency particulate air (HEPA) vacuum, wetting surfaces, and an air purifying respirator that is either single use or has replaceable particulate filters as approved by the Mine Safety and Health Administration (MSHA) or NIOSH are used to protect the employee from dust and exposure to asbestos and dust particles. There are many types of respirators. A respirator that is appropriate for the job being performed must be used. For example, a dust mask that is not fit-tested to the wearer is not the correct or adequate protection for asbestos exposure. Other PPE may include hard hats, gloves, coveralls, and appropriate footwear. Tool operating procedures may list the appropriate PPE required for tool operation. PPE is not a substitute for safe work practices and is not intended to be a sole source of hazard control. Rather, PPE should always be a supplement to other protective measures. Hazards can be eliminated or minimized by elimination, substitution, engineering, administrative methods, and PPE. Engineering can be used as a sole method of controlling hazards.
Administrative methods can be used to reduce hazard exposures by keeping employees away from the hazards. For example, administrative methods could include using fencing, roping off areas, and posting danger or warning signs. However, PPE is a supplement to one of the other methods employed to reduce hazard exposure. PPE is not reliable or effective when used as the sole means of protecting workers.
Following Operating Procedures Operating procedures for each tool are provided by the manufacturer. Standard operating procedures may also be developed by the employer. If operating procedures do not exist for a tool or equipment, then instructions for the safe use and maintenance of the equipment must be developed. For example, manual hand tools such as hammers, screwdrivers, and chisels may not include manufacturer’s instructions, but the employer should provide instructions for safe use and maintenance. Tool and equipment operating procedures often list the type of tasks for which the tool is intended to be used. Procedures may also list appropriate PPE that should be used while operating the tool. Failure to follow operating procedures may damage the tool or workpiece and possibly injure the user. For example, substituting a light-duty tool when the procedure calls for a heavy-duty tool can result in tool breakage or damage to the workpiece and lead to cuts, abrasions, or muscle strain. Operating procedures can also be used to develop a JHA, train employees, or resolve questions about which tool to use for a particular job. Many workplace policies prohibit employees from using tools or equipment they are not trained to use.
Inspecting Tools Tools must be inspected daily or before each use. They should be checked for sharpness, chips, wear, metal fatigue, and mushrooming before use. Mushrooming is a problem that occurs with tools such as chisels, wedges, or drift pins because
178 OCCUPATIONAL SAFETY AND HEALTH
constant hammering on the head distorts the tool. The term mushroom is used because of the tool head’s similar appearance to a mushroom. See Figure 9-11. Tools with mushroomed heads may shatter on impact, sending sharp fragments flying toward the user or other employees. Tools showing signs of mushrooming must be taken out of service and fixed or replaced.
to hazards. If additional accessories are used on the tool, they must be listed as approved by the tool manufacturer in the operating manual. Checklists are often available from tool manufacturers and suppliers to aid in tool inspection. Power Tool Inspections
Hand Tool Inspections TOOL IN GOOD CONDITION MUSHROOMING HAIRLINE CRACK CHIP
STATIONARY GUARD MOVING GUARD
Figure 9-12. Power tools, such as circular saws, must be inspected to make sure the guards are in place and functioning correctly.
Figure 9-11. Chisels may develop mushroom heads over time.
Inspections must be done for hairline cracks or small chips that may be early warning signs of breaks. Frequent inspection of handles is especially important. Damaged, defective, or worn tools are tagged and removed from service until repaired. Establishing a “Do Not Use” marking system for damaged or broken tools prevents others from using unsafe tools and equipment. Employers should not let employees use damaged tools until they have been repaired. Part of an inspection includes making sure appropriate guards are in place for the tool. Portable power tools and other handheld tools are designed with guards that protect the worker and others in the area from hazards created by rotating parts, flying chips, and sparks. For example, a circular saw has a stationary guard and a guard that moves as it makes contact with the stock as it is cut. See Figure 9-12. Removing or disabling guards can expose the worker and others in the area
Maintaining Tools Hand tools must be properly maintained to sustain efficiency on the job and to prevent injury to the user and others in the area. With repeated use, tools can become dull, cracked, loose, or mushroomed. When this happens, the tool must be taken out of service and fixed or replaced. Using a defective or inferior tool can cause severe injury. For example, if a wooden handle on a tool, such as a hammer or an axe, is loose, splintered, or cracked, the head of the tool may fly off and strike the user or other employees. The blades for cutting tools should be kept clean and sharp. Dull blades on tools are dangerous because they require excessive pressure and hammering to make them cut. Proper procedures must be used for sharpening blades.
Storing Tools Properly When not in use, tools should be stored in their cases or other appropriate containers where they are protected from damage. See Figure 9-13. Tools must never be left on
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ladders, scaffolds, or overhead work areas. All sharp-edge tools and chisels should be stored with the cutting edge down in a sheath. Workers should never carry unsheathed sharp tools in a pocket. Tool Storage
Milwaukee Electric Tool Corp.
Figure 9-13. When not in use, tools should be stored in their cases to protect them from damage.
Maintaining Clean Work Areas Good housekeeping is essential to working efficiently and keeping a safe work area. Hazards may be caused by clutter and overcrowding, general sloppiness, and poor organization. Dirty, greasy, and oily tools, work surfaces, and floors can lead to injuries. Employees should clean and put away all unneeded tools and materials. Grinding, filing, and sawing create debris that collects on floors and makes them slippery. Keeping paths clear of debris, unused hand tools, and cords helps to prevent tripping, slipping, and falling. Work areas should be designed and organized to facilitate an orderly work flow. Tables, cabinets, storage areas, and equipment should be located where they are convenient, but they should not create obstructions in work areas or paths to work areas. Electrical outlets, water supplies, and other apparatuses needed to operate or clean tools and equipment should be located where they are accessible and convenient, but they should not create hazards in the work area.
CASE STUDY Hand Tool Safety Using the proper tool for a task will help accomplish the task quicker and with better results. Well-maintained tools are important to keeping an injury-free work environment. On a Friday afternoon, approximately an hour before quitting time, a laborer was instructed to go to the perimeter of the company property and repair a broken fence post. The worker had already cleaned and stored his personal tools in his truck. He decided to use the general-use shop tools. The shop tools were not used frequently by employees, thus were lower quality and not well maintained. During the fence repair, the employee used a cordless drill. A couple of the drill bits were worn, so the employee selected the best one available even though there was a slight nick in the bit. While using the drill, the bit broke. The employee then decided to use nails instead of screws to repair the fence. A punch set was not in the toolbox, so the employee used a hammer and screwdriver to drive points for the nails. As the employee struck the screwdriver handle with the hammer, the screwdriver broke and a piece struck him in the face close to his right eye. There were several errors that occurred before the accident happened. The company did not maintain the tools adequately and did not enforce an adequate tool inspection and maintenance program. The employee did not examine the tools before using them and did not use the correct tools for the job. In addition, the employee did not use PPE. Safety professionals should audit tool inspection and maintenance programs. They should participate in preparing a JHA to ensure that there are adequate controls. The use of hand tools and portable tools, potential hazards, required maintenance, and appropriate personal protection should be included in job brieďŹ ngs and employee safety training.
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HAZARD CONTROLS FOR SPECIFIC TOOLS In the process of removing or preventing hazards, employees must understand the operation and functions of tools, recognize the hazards associated with the different types of tools, and know the safety precautions necessary to prevent those hazards from occurring. Any tool can be evaluated for its potential hazards and hazard controls. In addition to the inspection performed by the employee before each use, many employers implement a tool inspection program that includes a routine periodic inspection for tool maintenance or replacement.
• When hammers are used to strike other tools such as chisels, punches, and wedges, the striking face of the hammer should be larger than the tool it is striking. Hammers
Hammers A hammer is a striking or splitting tool with a hardened head fastened perpendicular to a handle. Common types of hammers used in industrial and mechanical applications include claw hammers, ball-peen hammers, engineer’s hammers, and sledgehammers. See Figure 9-14. A claw hammer is used to drive nails. A claw hammer can also be used to remove nails previously driven into a surface. Ball-peen hammers of the proper size are designed for striking chisels and punches. Ball-peen hammers can also be used for riveting, shaping, and straightening unhardened metal. Engineer’s hammers are doublefaced hammers used for driving large-size chisels, cold punches, rock drills, and hardened nails. Medium-size sledgehammers (5 lb to 8 lb) are used for driving stakes and other heavy-duty pounding. Hazard controls for using hammers include the following: • Wear appropriate eye protection such as safety glasses or goggles. Eye protection will protect the eyes from flying objects. • Select the appropriate size and type of hammer for the task. • Inspect the hammer for cracked handles, loose heads, marks, and other damage before use.
SLEDGEHAMMER The Stanley Works
Figure 9-14. Common types of hammers include claw hammers, ball-peen hammers, engineer’s hammers, and sledgehammers.
Pliers Pliers are hand tools with opposing jaws for gripping and/or cutting. Workers use pliers for various gripping, turning, cutting, positioning, and bending operations. Plier handles vary in length, thickness, and gripping material. Generally, the end of the plier handles should be long enough to provide sufficient leverage to perform the task efficiently and fit comfortably in the hand. The ends of the handles usually extend to just past the palm area. If the pliers are not a good fit, the user may experience muscle fatigue and hand cramping. Common pliers include slip-joint, tongue-and-groove, long nose or needle nose, locking, diagonalcutting, lineman’s, end-cutting, and selfadjusting. See Figure 9-15.
Chapter 9 — Hand and Portable Power Tools 181
SELF-ADJUSTING The Stanley Works
Figure 9-15. Pliers are commonly used for turning, bending, and cutting operations.
Slip-joint pliers are used to tighten box connectors, locknuts, and small-size conduit couplings. Tongue-and-groove pliers are used for a wide range of applications involving gripping, turning, and bending. The adjustable jaws of tongue-and-groove pliers enable adjustment to a wide range of sizes. Long nose pliers are used for bending and cutting wire and positioning small components. Locking pliers are used to lock onto a workpiece. Locking pliers can be adjusted to lock at any size with any desired amount of pressure. Diagonal-cutting pliers are used for cutting cables and wires that are too difficult to cut with side-cutting pliers. Lineman’s pliers are used for cutting cable, removing knockouts, twisting wire, and deburring metal pipe. End-cutting pliers are used for cutting wire, nails, rivets, etc., close to the
workpiece. Self-adjusting pliers work in the same manner as slip-joint pliers but automatically adjust to the size of the workpiece and lock in place. Hazard controls for using pliers include the following: • Wear appropriate eye protection such as safety glasses or goggles to protect the eyes from flying objects. • Inspect pliers for wear, loose handles, and other damage. Damage to the insulation of double-insulated pliers used for electrical circuits must be taken out of service. • Do not use pipe extenders or cheater bars on the handles of pliers to increase the leverage because they can break the tool or workpiece or injure the user. • Exposing pliers to excessive heat can cause the pliers to become brittle and break easily when used under normal conditions.
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Wrenches A wrench is a hand tool with jaws at one or both ends and is designed to turn bolts, nuts, or pipes. Common wrenches used in industry include socket, adjustable, Allen (hex key), combination, and pipe. See Figure 9-16. Wrenches
ALLEN (HEX KEY)
PIPE The Stanley Works
Figure 9-16. Common wrenches include socket, adjustable, Allen (hex key), combination, and pipe.
Socket wrenches are used to tighten a variety of items, such as hex-head lag screws, bolts, and various electrical connectors. Adjustable wrenches are used to tighten items such as various sizes of hex-head lag screws, bolts, and large conduit couplings. Allen wrenches are used for tightening hex-head bolts. A combination wrench is a
hand tool with an open-end wrench on one end and a closed-end box wrench on the other. Pipe wrenches can be straight, offset, strap, or chain. Pipe wrenches are used to tighten and loosen pipes and large conduit. Hazard controls for using wrenches include the following: • Wear appropriate eye protection such as safety glasses or goggles to protect the eyes from flying objects. • Inspect wrenches for wear, cracks, and other damage, such as burn marks indicating that the wrench was exposed to high temperatures. • Select a wrench with an opening that corresponds to the size of the nut to be turned. A wrench with too large an opening for the workpiece can spread the jaws of an openend wrench and batter the points of a box or socket wrench. • Check the tool to verify that it correctly corresponds to either standard or metric use. Standard wrenches are identified by fractions and metric wrenches are identified by whole numbers. Standard wrenches should be selected for standard fasteners, and metric wrenches should be selected for metric fasteners. • Use a box or socket wrench where possible because wrenches of these types, by design, are less prone to slipping. • Use a wrench with a straight handle where possible rather than an offset handle. Less force is needed to use a wrench with a straight handle. Offset handle wrenches are generally used in hard to reach places. • Use lubricants on corroded fasteners before wrench use to ease the pressure needed to loosen them.
SAFETY ADviSORY All wrenches should be pulled rather than pushed. An adjustable wrench should be turned so that the pulling force is applied to the stationary jaw side of the handle.
Chapter 9 — Hand and Portable Power Tools 183
Handsaws and Hacksaws A handsaw is a woodcutting hand tool that consists of a straight, toothed blade attached to a handle. The blade is moved back and forth against wood to produce cutting action. The main parts of a handsaw are the blade (including the toe and heel of the blade), teeth, back, and handle. See Figure 9-17. Although the basic constructions of all types of handsaws are similar, there are differences in the lengths and shapes of the blades and the numbers and shapes of the teeth. Most handsaws have a straight back, but skewback saws (curvedback saws) are also available. Handsaws
TEETH HANDLE TOE
The cut made by a handsaw is wider than the thickness of a saw blade to allow the blade to move freely through the material being cut. If the saw blade cannot move freely, the wood fibers pressing against the blade cause the saw to bind, making the cutting action difficult and the user more susceptible to injury. Handsaw teeth are alternately bent from side to side, which provides a wider cut than the blade thickness. High-quality handsaw blades are tapered from the blade top to the blade bottom. The top portion of the blade is thinner than the blade at the cutting edge, requiring less set in the teeth. A handsaw usually has a number printed on its blade indicating the number of points per inch. A blade with a low number has large teeth, and therefore makes a rougher cut. For example, an 8-point saw has larger teeth than an 11-point saw and produces a rougher cut than an 11-point saw. See Figure 9-18. When using a handsaw, the workpiece is positioned face up to prevent splintering on the face. The back of the workpiece splinters due to the cutting action of the blade.
Figure 9-17. The main parts of a handsaw include the blade, teeth, back, and handle.
Handsaw Blade Points
1″ = 8 POINTS
1″ = 11 POINTS
Hacksaws can be used to cut through various types of materials, including metal.
Figure 9-18. A handsaw usually has a number printed on its blade indicating the number of points per inch.
184 OCCUPATIONAL SAFETY AND HEALTH
A hacksaw is a metal-cutting hand tool with an adjustable steel frame for holding various lengths and types of blades. Blades are inserted with the teeth pointing away from the handle. Hacksaws can be straight handle or pistol-grip handle. See Figure 9-19. A straight-handle hacksaw is usually preferred for fine work. Either type of frame is adjustable for various blade lengths. Tension is applied to the blade to make it taut by means of a wing nut on the pistol-grip frame or a turning threaded handle on the straight-handle hacksaw. Hacksaws are used to cut workpieces such as metal pipe, PVC pipe, conduit, smalldiameter metal rods, rigid plastics, bolts, and nails. Hazard controls for using handsaws and hacksaws include the following: • Wear safety glasses or a face shield with safety glasses worn under it. • Choose a handsaw of the proper size and shape for the material to be cut. • Check the material to be cut for objects that can buckle or damage the saw, such as nails, screws, staples, and knots. • Hold the material to be cut fi rmly against a support such as a table, vise, or bench. • When starting a cut, carefully and slowly pull the blade upward until the blade creates a starting cut.
SAFETY ADviSORY If the material being cut is long, a wedge can be used to spread the material apart to prevent blade bind and to assist in blade cleaning.
Circular Saws A circular saw is a handheld or tablemounted power saw with teeth around the circumference of a circular blade that is rotated at high speed on a central axis or shaft. Circular saws are primarily used to cut wood but can also be used to cut certain types of plastic and metal. See Figure 9-20. Circular saws are used to cut lumber or wood panels to length and width. A circular saw blade turns in a counterclockwise direction, cutting the material from the underside through the top. Circular saws are equally efficient for crosscutting and ripping lumber and panel products and can be adjusted to cut angles ranging from 45º to 90º.
STRAIGHT HANDLE Milwaukee Electric Tool Corp.
Figure 9-20. Circular saws are used to cut various types of materials.
PISTOL-GRIP HANDLE The Stanley Works
Figure 9-19. Common hacksaw designs are straight handle and pistol-grip handle.
More serious work-related injuries occur from the use of a circular saw than from any other portable power tool. Many accidents are due to carelessness or tool malfunction. One of the most common causes of circular saw injuries is the retractable guard failing
Chapter 9 — Hand and Portable Power Tools 185
to snap back into position after the cut is completed. The guard may also jam when a woodchip lodges between the saw guard and blade. Intentionally wedging the guard is a highly dangerous practice and should not be done under any circumstances. Many safety features are integrated into circular saws to ensure safety when the tool is used properly. Circular saws are equipped with blade guards above and below the base. The upper guard is stationary and covers the saw to the depth of the teeth. The lower guard covers the saw to the depth of the teeth and automatically and instantly returns to the covering position when the saw is retracted from the work. The guard of a circular saw must never be wedged for any reason. Circular saws are equipped with a constant pressure switch or control that shuts off the power when the pressure is released. A circular saw must be properly grounded or double insulated to protect the user from electrical shock. Regulations that apply to the proper guarding and operation of circular and reciprocating saws are located in OSHA 1926.304 — Woodworking Tools. Hazard controls for operating circular saws include the following: • Wear appropriate eye protection such as safety glasses or goggles. • Verify the retractable guard is operational before using a circular saw. • Wait until the blade stops rotating before removing the saw from the material after completing a cut. • Stand to one side of a circular saw in case of kickbacks. • Always disconnect the electrical plug before changing blades or making adjustments. • Remove all damaged or cracked saw blades from service.
Reciprocating Saws A reciprocating saw is a multipurpose cutting tool in which the blade reciprocates (quickly moves back and forth) to create the cutting action. Reciprocating saw blades can be plunged directly into walls, floors, ceilings, and other resilient material. Reciprocating saws operate at 1700 to 2800 strokes per minute (at no load) and are used to make cuts into finished walls, ceilings, floors, and any other rigid materials. See Figure 9-21. Reciprocating saws can also be retrofitted with different types of saw blades for cutting small-diameter plastic or metal pipes, rods, and tubing. Reciprocating saws are equipped with a positive ON/OFF control, a constant pressure switch similar to a circular saw, or a variablespeed switch. Hazard controls for operating reciprocating saws include the following: • Use appropriate PPE. • Inspect the tool, guards, power cord, and work area. • Do not reach under the material being cut. • After completing a cut, wait until the motor stops before removing the saw from the material. • Always disconnect the electrical plug before changing blades or making adjustments. • Remove all damaged saw blades from service. Reciprocating Saws
SAFETY ADviSORY Work areas should be free from clutter, debris, and items unrelated to the task. In field environments, the work space should be cleared before using tools.
Figure 9-21. Reciprocating saws are used to make cuts into ﬁnished walls, ceilings, and floors.
186 OCCUPATIONAL SAFETY AND HEALTH
Chain Saws A chain saw is a handheld tool used to cut heavy timbers and pilings and is useful for demolition projects. See Figure 9-22. Chain saws are electrically powered or gasoline powered. Gasoline-powered chain saws are typically more powerful and commonly used in remote locations.
Chain Saws FRONT HAND GUARD CONSTANTPRESSURE SWITCH
CHAIN AND CUTTERS
GUIDE BAR HANDLE BAR ENGINE TRIGGER SWITCH STIHL Inc.
Figure 9-22. Chain saws are commonly used to cut heavy timbers and pilings in such operations as forestry, logging, and demolition.
Gasoline is a highly flammable substance that requires special care to ensure the safety of the operator and other employees in the area. Only gasoline from properly labeled storage containers should be used and the chain saw tank should not be overfilled. Additional information regarding the safe use of gasoline-powered and electric chain saws can be found in the instructions or user manual provided by the manufacturer. Hazard controls for operating chain saws include the following: • Establish written procedures, prepare a JHA, and train employees on the safe use of chain saws, the hazards of violating work procedures, and the use of PPE.
• Keep both hands on the chain saw when using it. Do not use the chain saw above shoulder height, including overhead, or outside a safe reach zone, such as when extending from a ladder. • Grip the handle bar when transporting a chain saw. • Carry a chain saw with the guide bar and chain pointing behind you. • Transport a chain saw with the engine turned off when moving to a different location or with the chain brake engaged for very short distances. • Only add gasoline to a gasoline-powered saw when the engine is cool. After pouring gasoline into the tank, wipe off any spilled fuel before starting the engine. • When starting the engine of a chain saw, start it on the ground with the chain brake engaged. • Wear gloves when checking the saw chain for tension or when oiling the chain before or after use. Do not touch the cutters with your fingers or bare hands. • Ensure the chain brake functions properly. • Wear appropriate PPE when operating a chain saw, such as head, hearing, foot, eye, face, hand, and arm protection. Hands are usually protected with heavyduty cotton, leather, or Kevlar® gloves. Legs may be protected using Kevlar chaps or pants. Each chain saw includes recommendations by the manufacturer on safe operating procedures.
Power Drills A power drill is a power-driven rotary tool used with a bit with cutting edges for boring holes in materials such as wood, metal, or plastic. Power drills can also be retrofitted with different types of attachments for operations such as screwing, grinding, and buffing. Power drills are either cordless (battery-operated) or corded (AC-powered) and are available in pistol-grip or D-handle designs. See Figure 9-23.
Chapter 9 — Hand and Portable Power Tools 187
MIlwaukee Electric Tool Corp. Skil Corporation
Figure 9-23. Power drills are available in pistol-grip or D-handle designs.
Cordless drills receive their power from a removable battery, which is commonly located in the handle. Batteries must be recharged at intervals based on the amount and type of usage. Cordless drills can be used for most of the same operations as corded drills. However, cordless drills are most effective for low-torque operations such as drilling thin wood and driving narrow screws. Corded drills are attached to an AC power source through an electrical cord, which is plugged into an electrical outlet, extension cord, or generator outlet. Corded drills are popular for high-torque operations such as drilling into concrete or drilling large holes in lumber. Hazard controls for operating power drills include the following: • Establish written procedures, prepare a JHA, and train employees on safety procedures, operating and maintaining power drills, work-related hazards, and personal protection. • Wear appropriate eye protection such as safety glasses or goggles to protect the eyes from flying objects. • Wear appropriate hearing protection to protect the ears from hazardous noise. • Inspect electric drills for loose power cord connections and frays or damage to cords before use. • Make sure the chuck key is removed from the chuck before starting the drill. A flying key can produce injuries.
• Check the auxiliary handle, if included, for secure installation. The auxiliary drill handle provides more control of the drill, especially if the drill stalls. See Figure 9-24. • Securely grasp the tool. Brace against stationary objects for maximum control. • Never force a drill into material. Apply just enough pressure to keep the drill bit cutting smoothly. Forcing a drill can cause the motor to overheat, damage the bit or workpiece, and reduce operator control.
Auxiliary Drill Handles
Milwaukee Electric Tool Corp.
AUXILIARY DRILL HANDLE
Figure 9-24. The auxiliary drill handle provides better control of the drill.
188 OCCUPATIONAL SAFETY AND HEALTH
Powered Portable Abrasive Wheels A powered portable abrasive wheel is a grinding tool that uses an abrasive wheel for reshaping, forming, cutting, polishing, and sharpening materials. It consists of an abrasive wheel mounted on a rotating shaft. Abrasive wheels are available in varying degrees of coarseness and are chosen based on the type of material to be ground. Abrasive wheel tools create special safety problems because they may throw off flying fragments or can fly off the rotating shaft. See Figure 9-25. Powered Portable Abrasive Wheel Tools
Milwaukee Electric Tool Corp.
Figure 9-25. A powered portable abrasive wheel tool is used to reshape, form, cut, polish, and sharpen materials.
Before an abrasive wheel is mounted, the operator should inspect it closely for cracks or damage and conduct a sound test or ring test to be sure that it is free from cracks or defects. To test an abrasive wheel, the wheel is tapped gently with a light, non-metallic instrument such as a pencil for a small wheel or a heavy wood stick for a large wheel. A metallic ring tone indicates the wheel is sound and undamaged. If the wheel produces a dull thud or has a dead tone, indicating damage, the abrasive wheel could fall apart while in operation and should not be used. To prevent the wheel from cracking, the user should inspect it to ensure it fits freely on the spindle. The spindle nut should be tightened enough to hold the wheel in place without distorting the flange. The operator’s
manual provided by the manufacturer gives recommendations on how tightly to secure the wheel on the spindle. Due to the possibility of a wheel disintegrating (exploding) during start-up, the worker should not stand directly in front of the wheel as it accelerates to full operating speed. Portable grinding tools are equipped with guards to protect workers from the moving wheel surface and from flying fragments in case of breakage. Additional hazard controls for operating powered portable abrasive wheel tools include the following: • Establish standard operating procedures and train employees on the safety operations, hazards, hazard controls, and personal protection for the use and maintenance of abrasive wheels and equipment. • Wear appropriate eye protection such as safety glasses or goggles to protect eyes from flying objects. • Wear appropriate hearing protection to protect from hazardous noise. • Wear nonﬂ ammable coveralls to prevent sparks from igniting clothing. • Turn off the power when the abrasive wheel tool is not in use. • Keep guards in place when using the abrasive wheel. • Keep the equipment and work area clean and free from clutter and debris.
Pneumatic Tools Most pneumatic tools are powered by compressed air traveling through an air hose, which is connected to an air compressor. A compressor has one or more pistons, which pull air into the cylinder on the downstroke and push the air into the hose and pneumatic tool on the upstroke. A continuous supply of compressed air flows through the hose and into the tool reservoir. The amount of air pressure required to operate a pneumatic tool depends on its size and the type of operation being performed. Air pressure delivered to the pneumatic tool is adjusted by a regulator valve on the compressor.
Chapter 9 — Hand and Portable Power Tools 189
The basic component of a pneumatic tool, such as a nailer or stapler, is a piston head charged by air that, in turn, pushes a piston that drives a nail or staple. See Figure 9-26. When pneumatic tools are used, the safety of the operator and other people in the immediate area must be considered. For example, when panels are fastened to studs or joists, no one should be on the other side of the wall or below the joists. If the nail or staple misses the stud or joist, it could go through the panel and severely injure someone. Other essential safety precautions that must be observed when using pneumatic tools are as follows: • Follow proper operating procedures as outlined in the operator’s manual for the particular tool.
• Wear safety glasses and a face shield where possible. Wood chips, concrete, or a deflected nail can cause serious eye or facial injury. • Ensure that air hoses and connections are in good operating condition. Air hoses that are larger than ¹⁄₂″ in diameter must have a safety device at the air compressor or branch line to stop airflow in case of hose failure. • When using a portable air compressor, ensure that exposed belts have guards on both sides to reduce the possibility of injuries to fingers and hands. • Use the correct nailer or stapler for the job, and use the correct size of nail or staple. Refer to manufacturer recommendations.
Pneumatic Nailer Operation VALVE PLUNGER
3 CHAMBER PLASTIC TUBE NAIL
Air enters reservoir from compressor.
When trigger is pulled, air is released to valve plunger.
Valve plunger exerts pressure on piston head to drive piston.
Piston drives nail.
Figure 9-26. Pneumatic tools are powered by compressed air.
Magazine feeds next nail into chamber.
OCCUPATIONAL SAFETY AND HEALTH
• Do not lift or carry a pneumatic nailer or stapler by the air hose. • Inspect pneumatic nailers and staplers before each use to ensure that the firing mechanism and safety features areoperating properly. Test the tool by firing it into a block of wood before using the nailer or stapler for the desired application. • Point the tip of a pneumatic nailer or stapler away from your body and other workers. • Only use pneumatic tools that meet or exceed OSHA standards. Per OSHA 1926.302 — Power-Operated Hand Tools, pneumatic nailers and staplers that operate at more than 100 psi air pressure must have a safety device on the tip to prevent the nailer or stapler from ejecting fasteners unless the tip is in contact with the work surface. • Disconnect pneumatic tools from the air supply when the tools are not in use. Pneumatic tools should be equipped with a fitting that releases air pressure from the tools when disconnected. • When toenailing, do not support or back up a workpiece with a foot or knee. • Always keep your fi nger off the trigger when a pneumatic tool is not in use.
Powder-Actuated Tools Powder-actuated tools, often referred to as PATs or stud guns, are used to fasten building
materials or other objects to concrete, masonry, and steel without predrilling holes for anchors. Powder-actuated tools are used to fasten wood to concrete, wood to steel, steel to concrete, and metal connectors to steel. See Figure 9-27. For example, powderactuated tools are commonly used to fasten bottom plates of wood-framed walls to concrete slabs and foundation walls. In concrete buildings, structural components such as top and bottom plates and corner studs of wood interior walls are secured to the floors, walls, and ceilings with powder-actuated tools. Powder-actuated tools are also used to attach the top and bottom channel tracks for metal-framed walls and solid gypsum board partitions. Powder-actuated tools are similar in operating principle to conventional firearms. Powder-actuated tools operate on the indirect-acting principle. A powder charge triggered in the chamber of a powderactuated tool produces expanding gases. The gases propel a piston, which in turn drives the fastener into the material being attached to the concrete or steel. See Figure 9-28. Powder-actuated tools are designed so they will not operate unless pressed against a work surface with a force at least 5 lb greater than the total weight of the tool. In addition, the tool may not operate if it is tilted more than 8° from the work surface. An integral safety feature does not permit the tool to fire until pressure is exerted to depress the safety mechanism and deactivate the trigger interlock.
Powder-Actuated Tool Applications
WOOD TO CONCRETE
WOOD TO STEEL
STEEL TO CONCRETE
METAL CONNECTORS TO STEEL
Figure 9-27. Powder-actuated tools are used to fasten wood to concrete, wood to steel, steel to concrete, and metal connectors to steel.
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Powder-Actuated Tool Operation
Igniting the powder load produces expanding gases, which propel a piston that drives the fastener into the work surface.
Trigger is pulled.
Released firing pin ignites powder load.
Expanded gases propel piston.
Propelled piston drives fastener.
Figure 9-28. Powder-actuated tools are powered by an explosive charge.
Powder-actuated fastening tools must meet the design requirements of ANSI/ASSE A10.3, American National Standard-Construction and Demolition Operations- Safety Requirements for Powder-Actuated Fastening Systems. Qualified operators must be trained by an authorized instructor of the tool manufacturer, pass a written examination, and have an operator’s qualification card. The operator’s qualification card is supplied by the manufacturer, issued by the instructor, and signed by both the instructor and the operator. Explosive actuated fastening tools should be secured in a locked container when not in use to prevent use by untrained personnel. Only workers who have been trained in the operation of a powder-actuated tool and have obtained an operator license can operate a powder-actuated tool. The operator must take and satisfactorily pass a quiz on the safe operation of powder-actuated tools. A qualified instructor can be located by contacting the regional office of the tool manufacturer or by contacting the Powder Actuated Tool Manufacturers’ Institute, Inc. (PATMI).
Powder-actuated tool operators must wear proper PPE such as safety goggles and earplugs or earmuffs. Powder-actuated tools should not be used in a flammable or explosive environment since the ignition of the charge produces a spark. Adequate ventilation must be provided when the tool is used in confined spaces. Other workers should not stand close by or to one side of the operator. If a drive pin hits a reinforcing steel bar in the concrete, the pin can ricochet in a horizontal direction. Powder-actuated tool operators should not drive fasteners into easily penetrated materials unless the materials are backed by a substance that will prevent the drive pin or threaded stud from passing completely through.
SAFETY ADviSORY Because powder-actuated tools operate like loaded guns, they must always be handled as if they are loaded and only be operated by specially trained employees.
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Chapter 09 Review and Resources Access Code: 674900
Powder-actuated tools must be inspected and tested at the start of each shift or before each use, as appropriate, to ensure that safety devices are in proper operating condition. Tools that are not operating properly should be immediately removed from service and repaired. Precautions should be taken to prevent a powder-actuated tool from firing accidentally. Powder-actuated tools should not be loaded until immediately prior to firing. The tool must always be brought to the intended firing position before pulling the trigger. If a powder-actuated tool misfires, the tool must be held in place for at least 30 sec before being operated a second time. If the tool does not fire again, hold the tool in place for another 30 sec and then proceed to remove the load following the instructions provided by the manufacturer. If the problem is due to a tool defect, remove the tool from service. Additional hazard controls for operating powder-actuated tools include the following: • Establish written policies and procedures for the safe operation of powder-actuated tools that include operator training, recognition of workplace and tool hazards, hazard controls, and personal protection. • Never point any powder-actuated tool at a person, whether the tool is loaded or unloaded.
• Before firing a powder-actuated tool, inspect the unloaded chamber to ensure the barrel is clean and there are no obstructions. • Keep hands away from the open barrel end. • Be aware of electrical circuits and use caution when driving fasteners near electrical circuits. • Do not leave a powder-actuated tool unattended. • Do not carry a loaded tool from the job. • Store tools and cartridges in a locked container when they are not in use. Be sure the tool is unloaded before storing it. • Never carry fasteners or other hard objects in the same container or pocket as powder loads. • Post warning signs stating powderactuated tools are in use within 50′ of the area where the tool is being used. • Use a spall guard whenever possible to minimize flying particles. • Use caution when driving pins into steel beams as the pin may ricochet and exit toward the operator. • Safely dispose of misfired powder loads by submerging in water.
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CHAPTER SUMMARY • OSHA general industry regulations for hand and portable power tools are in OSHA 1910 Subpart P — Hand and Portable Powered Tools and Other Hand-Held Equipment. • All electric corded tools, equipment, or devices must use either ground-fault circuit interrupter (GFCI) outlets or an acceptable means of grounding to ensure worker safety. • Constant strain on muscles from operating tools or using tools that are not ergonomically designed for the task can lead to cumulative trauma or repetitive motion injuries. • Tool operating procedures can be used to determine the proper tool for the job, the proper PPE when using the tool, and training for employees. • Tools that are dull, cracked, loose, defective, or damaged must be taken out of service and fixed or replaced. • One of the most common causes of circular saw injuries is the retractable guard failing to snap back into position after the cut is completed. • Powder-actuated tools are designed so they will not operate unless pressed against a work surface with a force at least 5 lb greater than the total weight of the tool.
KEY TERMS A chain saw is a handheld tool used to cut heavy timbers and pilings and is useful for demolition projects. A circular saw is a handheld or table-mounted power saw with teeth around the circumference of a circular blade that is rotated at high speed on a central axis or shaft. A hacksaw is a metal-cutting hand tool with an adjustable steel frame for holding various lengths and types of blades. A hammer is a striking or splitting tool with a hardened head fastened perpendicular to a handle. A handsaw is a woodcutting hand tool that consists of a straight, toothed blade attached to a handle. A hand tool is any of a variety of tools that are used manually. A hydraulic tool is any of a variety of tools powered by compressed liquid. Pliers are hand tools with opposing jaws for gripping and/or cutting. A pneumatic tool is any of a variety of tools powered by compressed air. A portable power tool is any of a variety of tools that are easily moved and powered by electricity, pneumatic or hydraulic power, liquid fuel, or an explosive charge. A powder-actuated tool is any of a variety of tools powered by a controlled explosion. A power drill is a power-driven rotary tool used with a bit with cutting edges for boring holes in materials such as wood, metal, or plastic. A powered portable abrasive wheel is a grinding tool that uses an abrasive wheel for reshaping, forming, cutting, polishing, and sharpening materials. A reciprocating saw is a multipurpose cutting tool in which the blade reciprocates (quickly moves back and forth) to create the cutting action. Tensile strength is the maximum amount of force that can be used to pull a material before it breaks. A wrench is a hand tool with jaws at one or both ends and is designed to turn bolts, nuts, or pipes.
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Review 1. What are the OSHA regulations that cover hand and portable power tools? 2. Identify six hazards associated with hand and portable power tools. 3. When inspecting a tool before use, what are some general items the user should check for? 4. How is the best tool for the job determined? 5. Explain the hazard controls for power drills. 6. How is the training for a powder-actuated tool different from training for other hand or portable power tools? 7. What safety standard should be referenced for information on arc flash protection? 8. Explain the safety provisions for the use of circular saws. 9. Explain the procedure for inspecting an abrasive wheel. 10. List symptoms that may indicate a health problem due to awkward body positions.
Published on Sep 1, 2016
Occupational Safety & Health provides an overview of potential workplace hazards, necessary safety practices, and how various processes need...