Hand and Power Tool Safety Clark Safety & Loss Control

Introduction Portable Power Tool: A tool that can be held in the operators hands, but is not hand powered. Four common sources of power. Electricity Pneumatic Battery Engine There are advantages and disadvantages for each type of power source.

Regulations Covering Hand and Power Tools For General Industry; 1910 Subpart P, Hand and Portable Power Tools and Other Hand-Held Equipment. 1910.241, Definitions. 1910.242, Hand and portable powered tools and equipment, general. 1910.243, Guarding of portable powered tools. 1910.244, Other portable tools and equipment.

Regulations Hand Tools Each employer shall be responsible for the safe condition of tools & equipment used by employees, including tools & equipment which may be furnished by employees.

Regulations Hand Tools Compressed air used for cleaning; Compressed air shall not be used for cleaning purposes, except where reduced to less than 30 p.s.i., and then only with effective chip guarding & personal protective equipment.

Regulations Hand Tools Employers shall not issue or permit the use of unsafe hand tools. Wrenches, including adjustable, pipe, end, & socket wrenches shall not be used when jaws are sprung to the point that slippage occurs.

Regulations Hand Tools Impact tools, such as drift pins, wedges, and chisels, shall be kept free of mushroomed heads. The wooden handles of tools shall be kept free of splinters or cracks and shall be kept tight in the tool.

General Safety Precautions Employees who use hand & power tools, and are exposed to the hazards of falling, flying, abrasive & splashing objects, or exposed to harmful dusts, fumes, mists, vapors, or gases , (must be provided with the particular PPE necessary to protect them from the hazard).

General Safety Precautions Employees and employers have a responsibility to work together to establish safe working procedures. If a hazardous situation is encountered, it should be brought to the attention of the proper individual immediately.

General Safety Precautions Appropriate PPE should be worn due to hazards that may be encountered while using portable power tools and hand tools. Floors should be kept clean & dry as possible to prevent accidental slips with or around dangerous hand tools.

Hand Tools Hand tools are non-powered. They include anything from axes to wrenches. The greatest hazards posed by hand tools result from misuse and improper maintenance.

Hand Tool Hazards Hazards are usually caused by misuse and improper maintenance. Do not use: Impact tools (chisels and wedges) when heads have mushroomed. A screwdriver as a chisel. 1926.301 • If a screwdriver is used as a chisel, the tip of the chisel may break and fly off, hitting the user or other employees. • 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. • If the jaws of a wrench are sprung, the wrench might slip. • If impact tools, such as chisels, wedges, or drift pins have mushroomed heads, the heads might shatter on impact, sending sharp fragments flying toward the user or other employees.

Hand Tool Hazards Do not use: Wrenches when jaws are sprung. Tools with taped handles – they may be hiding cracks. Tools with loose, cracked or splintered handles.

Hand Tool Misuse examples: If a wooden handle on a tool is loose, splintered, or cracked, the head of the tool may fly off & strike the user or another worker. A wrench must not be used if its jaws are sprung, because it might slip. Impact tools such as chisels, wedges, or drift pins that have mushroomed heads, might shatter on impact, sending sharp fragments flying.

Hand Tools The employer is responsible for the safe condition of tools & equipment used by employees; but, The employee has the responsibility for properly using & maintaining tools.

Hand Tools Saw blades, knives, or other tools need to be directed away from areas & employees working in close proximity. Knives & scissors must be sharp. Dull tools can be more hazardous than sharp ones.

Spark Resistant Tools "Non-sparking", "spark-resistant" or "spark-proof" are 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.

Spark Resistant Tools Preferred "non-sparking" metals have less tensile strength than steels usually used to make tools. A lower tensile strength means the metal has less strength. It also means that these tools are softer, wear down more quickly than ordinary steel tools, & have to be dressed more frequently.

Non-Sparking Tools

Today’s Power Tools 1. Offer more power, adaptability, & dependability than ever ! 2. With enhanced tool performance comes increased responsibility.

Power Tools 1. Must be fitted with guards & safety switches. 2. Extremely hazardous when used improperly. 3. Different types, determined by their power source: Electric Pneumatic Liquid fuel Hydraulic Powder-actuated 1926.300(b) and 1926.302

Today’s Power Tools Personnel responsible for specifying & using power tools have a responsibility to check out a tool's safety features; Then ensure that, common sense is followed at all times.

Hazards of Power Tools Avoid hazards by following five basic safety rules: Keep tools in good condition. Use the right tool for the job. Examine tools for damage before use. Operate according to the manufacturer's instructions. Use the proper protective equipment.

General Safety Guidelines for Power Tools Manufacturers' tool owner/operator manuals, shipped with tools & accessories, are a source for proper procedures for specific tool use.

General Safety Guidelines for Power Tools (cont) Know the power tool: Read & understand the owner's manual. Labels affixed or included in the shipping container must be read & understood.

General Safety Guidelines for Power Tools (cont) Ground all tools unless double insulated. Do not use power tools in a damp, wet and/or explosive atmosphere -- fumes, dust or flammable materials.

General Safety Guidelines for Power Tools (cont) Be aware of all power lines and electrical circuits, water pipes, and other mechanical hazards in the work area, particularly those below the work surface, hidden from the operator's view, that may be contacted.

General Safety Guidelines for Power Tools (cont) Wear proper apparel. Do not wear loose clothing, dangling objects or jewelry. Long hair must be restrained. Gloves should not be worn when operating certain power tools. Check appropriate tool manuals.

General Safety Guidelines for Power Tools (cont) Power tools can be hazardous when improperly used. There are several types of power tools, based on the power source they use: electric, pneumatic, liquid fuel, hydraulic, & powder-actuated.

General Safety Guidelines for Power Tools (cont) Employees should be trained in the use of all tools - not just power tools. Understand the potential hazards as well as the safety precautions to prevent hazards from occurring.

General Safety Guidelines for Power Tools General precautions should be observed by power tool users: Never carry a tool by the cord or hose. Never yank the cord or the hose to disconnect it from the receptacle.

General Safety Guidelines for Power Tools Keep cords & hoses away from heat, oil, & sharp edges. Disconnect tools when not in use, before servicing, and When changing accessories such as blades, bits & cutters.

General Safety Guidelines for Power Tools All observers should be kept at a safe distance from the work area. Secure work with clamps or a vise, freeing both hands to operate the tool. Avoid accidental starting. Do not hold a finger on the switch button while carrying a plugged-in tool.

General Safety Guidelines for Power Tools (cont) Be maintained with care. Kept sharp and clean. Follow user's manual for lubricating and changing accessories. Keep good footing & maintain good balance.

General Safety Guidelines for Power Tools (cont) The proper apparel should be worn. (Loose clothing, or jewelry can become caught in moving parts.) All portable electric tools that are damaged shall be removed from use & tagged "Do Not Use."

Electrocution Warning The most serious hazard of using power tools is the possibility of electrocution. Burns & even slight shocks can lead to injuries or even heart failure.

General Safety Precautions-Electric Tools (cont) Under certain conditions, even a small amount of current can result in fibrillation of the heart & eventual death. A shock also can cause the user to fall off a ladder or other elevated work surface.

General Safety Precautions-Electric Tools (cont) Electric tools must either have; 1) A three-wire cord with ground and be grounded, 2) Be double insulated, or 3) Be powered by a low-voltage isolation transformer.

General Safety Precautions-Electric Tools (cont) Double insulation is more convenient. The user and the tools are protected in two ways: 1) By normal insulation on the wires inside, & 2) By a housing that cannot conduct electricity to the operator in the event of a malfunction.

General Safety Precautions-Electric Tools (cont) General practices should be followed when using electric tools: Electric tools should be operated within their design limitations. Gloves, if kept clear of rotating parts, and safety footwear are recommended during use of electric tools.

General Safety Precautions-Electric Tools (cont) When not in use, tools should be stored in a dry place. Electric tools should not be used in damp or wet locations. Work areas should be well lighted.

Power Tool Accessories and Attachments (cont) Don't use an accessory or attachment unless: The power tool manufacturer recommends its use on the product; The accessory limitations and specifications -- such as speed, size, mounting and guarding requirements, etc. –(match the limitations and specifications of the power tool as shown in the owner/operator's manual); and,

Power Tool Accessories and Attachments (cont) unless: The use of accessory does not require the removal of or defeating of any guards, barriers or other safety-related devices on the power tool, unless they are replaced by other appropriate guards or protective devices. Unplug tools before installing, adjusting and changing any accessory or attachment of any kind.

Powered Abrasive Wheel Tools Powered abrasive grinding, cutting, polishing, and wire buffing wheels create special safety problems because they may throw off flying fragments. Before an abrasive wheel is mounted, it should be inspected closely and sound- or ring-tested to be sure that it is free from cracks or defects.

Powered Abrasive Wheel Tool To test, wheels should be tapped gently with a light non-metallic instrument. If they sound cracked or dead, they could fly apart in operation and so must not be used. A sound and undamaged wheel will give a clear metallic tone or "ring."

Inspecting Abrasive Wheels Before mounting: Inspect closely for damage. Perform sound- or ring-test to ensure free from cracks / defects. To test: Tap wheel gently with a light, non-metallic instrument. If wheel sounds cracked or dead, do not use it. 1926.303 (c)(7) A stable and undamaged wheel when tapped will give a clear metallic tone or “ring.”

Abrasive Wheel Use To prevent cracking: Fit the wheel on the spindle freely. Tighten the spindle nut enough to hold the wheel in place without distorting the flange. 1926.303 (c)(8), 1926.303 (c)(9) Ensure the spindle speed doesn’t exceed the maximum speed marked on the wheel

Powered Abrasive Wheel Tools If the wheel does not “ring” when tapped & is still used, the wheel could disintegrate during operation & cause serious injury or even death. Grinder injury

Abrasive Wheel Work Rests Keep work rests not more than 1/8th inch from wheel surface. This prevents jamming the work between the wheel and the rest, which may cause the wheel to break. Don’t adjust wheel while it’s rotating. 1926.303(e) On offhand grinding machines, use work rests to support the work. They are to be equipped with adjustable work rests to compensate for wheel wear. The work rest shall be securely clamped after each adjustment. The adjustment shall not be made with the wheel in motion. 1926.303(c)(2) Floor and bench-mounted grinders shall be provided with work rests which are rigidly supported and readily adjustable. Keep these work rests not more than one-eighth inch from the surface of the wheel.

Abrasive Wheels and Tools May throw off flying fragments Equip with guards that: Cover the spindle end, nut, & flange projections Maintain proper alignment with the wheel Guard so that a minimal amount of the wheel is exposed ¼” 1926.303(b)(2), 1926.303 (c)(5)

Failure to Ring Test Failure to ring test could result in a disintegrating wheel. This could lead to serious injury or death. Spindle guard removed for better viewing

Powered Abrasive Wheel Tools To prevent the wheel from cracking, the user should be sure it fits freely on the spindle. The spindle nut must be tightened enough to hold the wheel in place, without distorting the flange.

Powered Abrasive Wheel Tools Follow the manufacturer's recommendations; Care must be taken to assure that the spindle wheel will not exceed the abrasive wheel specifications. Due to the possibility of a wheel disintegrating (exploding) during start-up; never stand directly in front of the wheel as it accelerates to full operating speed.

Powered Abrasive Wheel Tools Portable grinding tools need to be equipped with safety guards; To protect workers from the moving wheel surface. From flying fragments in case of breakage.

Powered Abrasive Wheel Tools In addition, when using a powered grinder: Always use eye protection. Turn off the power when not in use. Never clamp a hand-held grinder in a vise.

Portable Circular Saws The circular saw is probably the most commonly used power saw & perhaps the most commonly abused. Familiarity should not breed carelessness. The following are specific safety musts when using any portable circular saws.

Portable Circular Saws Do not use a circular saw that is too heavy for you to easily control. Do not wear; loose clothing, long hair, or dangling jewelry. Always wear PPE.

Portable Circular Saws Circular saws are one of the most commonly used power saws, and one of the most commonly abused. Familiarity should not breed carelessness.

Portable Circular Saw “PPE” Always wear safety glasses /goggles with side shields and a full face shield. Use a dust mask in dusty work conditions. Wear hearing protection during extended periods of operation.

Portable Circular Saw “Safety Precautions” Be sure the switch actuates properly. & (returns to the off position after release). Use sharp blades; Dull blades cause binding, stalling & possible kickback. They are dangerous, waste power & reduce motor and switch life.

Portable Circular Saw “Safety Precautions” Use the correct blade for the application. Check: 1. Does it have the proper size & shape arbor hole ? 2. Is the speed marked on the blade at least as high as the no-load RPM on the saw's nameplate ?

Portable Circular Saw “Safety Precautions” Is the blade guard working ? 1. Check for proper operation before each cut. 2. Check often to ensure that the guard return’s to the normal position quickly. If a guard seems slow to return or hangs up, repair or adjust it immediately. 3. Never defeat the guard to expose the blade by, (tying it back or removing it.)

Portable Circular Saw “Safety Precautions” Before starting a circular saw; 1. Be sure the power cord & extension cord are out of the blade path & are long enough to freely complete the cut. 2. Keep aware of the cord location. A sudden jerk or pulling on the cord can cause loss of control of the saw & a serious accident.

Portable Circular Saw Safety Precautions For maximum control, (hold the saw firmly. ) Clamp workplaces; (Check to be sure clamps remain secure. ) Avoid cutting small pieces that can't be properly secured & material on which the saw shoe can't properly rest.

Portable Circular Saw Safety Precautions When starting the saw; 1. Allow the blade to reach full speed before contacting the workplace. When making a partial cut, or if power is interrupted; 1. Release the trigger immediately & don't remove the saw until the blade has come to a complete stop.

Guarding - Point of Operation radial arm saw equipped with proper point of operation guards 1926.300 (b)(4) and 1926.304(g) The guarding device shall be designed and constructed to prevent the operator from having any part of his body in the danger zone during the operating cycle. The point of operation is where the work is actually performed on the materials – it must be guarded

Table Saw Guarding Use a hood for guarding Hood guard 1926.304(h)(1) Hand-fed crosscut table saws Each circular crosscut table saw shall be guarded by a hood Use a hood for guarding

Miter Box Saws & Chop Saws 1. Because of the saw's downward cutting motion, stay alert to keeping hands & fingers away from the blade's path. 2. Be sure all guards are in place and working. 3. Use only recommended size and RPM rated blades. 4. When installing or changing a blade, be sure blade is correctly positioned and secured on the saw arbor.

Power Tools – Precautions Electric Cords Don’t carry portable tools by the cord. Don’t use electric cords to hoist or lower tools. Don’t yank cord to disconnect it !!! 1926.302(a)(2)

Power Tools – Precautions Electric Cords Keep cords and hoses away from heat, oil, & sharp edges. Remove damaged electric tools & tag them: “Do Not Use”. 1926.302(a)(2)

Electric Power Tools To protect a worker from shock, these tools must: 1. Have a 3-wire cord plugged into a grounded receptacle. 2. Be double insulated. or 3. Be powered by a low-voltage isolation transformer 1926.302 (a)(1) Three-wire cords contain two current-carrying conductors and a grounding conductor. Any time an adapter is used to accommodate a two-hole receptacle, the adapter wire must be attached to a known ground. The third prong must never be removed from the plug. Double-insulated tools are available that provide protection against electrical shock without third-wire grounding. On double-insulated tools, an internal layer of protective insulation completely isolates the external housing of the tool. Double insulated markings Plug with a grounding pin

Portable Drills Available in a variety of types & capacities, portable power drills are the most used power tools. Because of their handiness and application to a wide range of jobs, (receive heavy use.) Need to check the drill's capacity, limitations, & accessory recommendations.

Portable Drill Safety Precautions Check for loose power cord connections & frays or damage to the cord. (Replace damaged tool & extension cords immediately.) Be sure the chuck is tightly secured to the spindle. This is especially important on reversible type drills.

Portable Drill Safety Precautions Tighten the bit securely as prescribed. (The chuck key must be removed from the chuck before starting the drill. A flying key can be an injury-inflicting missile.)

Portable Drill Safety Precautions 1. Check auxiliary handles, if part of the tool. (Be sure they are securely installed.) 2. Always hold or brace the tool securely. 3. Don't force a drill.

Switches Hand-held power tools must be equipped with one of the following: Constant pressure switch; Shuts off power upon release Examples: circular saw, chain saw, grinder, hand-held power drill. On-Off Switch; Examples: routers, planers, laminate trimmers, shears, jig saws, nibblers, scroll saws. 1926.300(d) Switches Use "on-off" control: hand-held powered platen sanders, grinders with wheels 2-inch diameter or less, routers, planers, laminate trimmers, nibblers, shears, scroll saws, and jigsaws with blade shanks one-fourth of an inch wide or less Use momentary contact "on-off" control and may have a lock-on control provided that turnoff can be accomplished by a single motion of the same finger or fingers that turn it on: hand-held powered drills, tappers, fastener drivers, horizontal, vertical, and angle grinders with wheels greater than 2 inches in diameter, disc sanders, belt sanders, reciprocating saws, saber saws, and other similar operating powered tools. Use a constant pressure switch which shuts off power when released: All other hand-held powered tools, such as circular saws, chain saws, and percussion tools without positive accessory holding means

Pneumatic (compressed air) Advantages; Disadvantages ; Smaller dimensions for torque produced Torque easily adjusted (changing pressure) Popular in hazardous environments Disadvantages ; Air must be clean & dry. A blast of high pressure air can embed objects in the skin or eyes. Air hose more difficult to manage than electric cord.

Pneumatic Tools Powered by compressed air; 1. Includes nailers, staplers, chippers, drills & sanders. 2. Main hazard - getting hit by a tool attachment or by a fastener the worker is using with the tool. 3. Take the same precautions with an air hose that you take with electric cords.

Pneumatic Tools 1. Pneumatic tools are powered by compressed air & include chippers, drills, hammers, & sanders. 2. Dangers encountered in the use of pneumatic tools; 3. Getting hit by one of the tool's attachments or fastener being used with the tool. 4. Eye protection is required, and a face shield is recommended when working with pneumatic tools.

Pneumatic Powered Tools 1. Tool retainer; A tool retainer shall be installed on each piece of equipment, which, without such a retainer, may eject the tool. 2. Air hose; Hose and hose connections used for conducting compressed air to utilization equipment shall be designed for the pressure and service to which they are subjected.

Pneumatic Tools A safety clip or retainer, must be installed to prevent attachments from being unintentionally shot from the barrel. Screens set up to protect nearby workers from flying fragments from chippers, riveting guns, staplers, or air drills. Compressed air guns should never be pointed toward anyone. Users should never "dead-end" it against themselves or anyone else.

Nail Guns Four types Power Fasteners 1. Brad 2. Framing 3. Finishing 4. Staple Power A. Pneumatic Electric B. Fuel cell Fasteners 1/4 inch brad and staples up to 4 inch nails.

Nail Guns Popular because they are fast and efficient; 1. Produce enough force to drive 2 - 3 inch nail into dense wood. 2. Accelerate nail to 1,000 feet per second.

Pneumatic Tools When using pneumatic tools; check to see that they are fastened securely to the hose to prevent from becoming disconnected. A short wire or positive locking device attaching the air hose to the tool will serve as an added safeguard.

Pneumatic Powered Tools All pneumatically driven nailers, staplers, & other similar equipment, which operate at more than 100 P.S.I. pressure at the tool shall have a safety device on the muzzle to prevent the tool from ejecting fasteners, unless the muzzle is in contact with the work surface.

Pneumatic Powered Tools The manufacturer's safe operating pressure for hoses, pipes, valves, filters, and other fittings shall not be exceeded. The use of hoses for hoisting or lowering tools shall not be permitted.

Pneumatic Powered Tools All hoses exceeding 1/2-inch inside diameter shall have a safety device at the source of supply or branch line to reduce pressure in case of hose failure. Working with noisy tools such as jackhammers requires proper, hearing protection.

Caring for the Compressed Air System Using pneumatic tools requires an efficient compressor system to adequately power the tools.

Compressor System Guidelines 1. Before making or breaking any air connection, always turn off the air supply. (Never kink the hose as a shortcut!) 2. Protect the air hose from damage. Move it out of the way of vehicles so that it isn't run over, or drag hoses around sharp corners. 3. Be sure to use the proper size air hose and fittings to keep air pressure at a maximum throughout the entire line.

Compressor System Guidelines 4. To ensure the best connection, clear any dirt off before connecting the air hose to the tool. 5. When the tool is connected, check the hose and all connections for leaks or damage before using the tool. 6. Maintain a clean, dry, regulated source of air to operate air tools. (Filters, regulators, and lubricators.)

Contaminates in the System The most common problem is water in compressed air; Condensed water vapor & dirt left in the air line may result in problems: 1. Sluggish tool operation, and more frequent repair. 2. Poor results in spraying & other types of finishing work . 3. Washing away of required lubricants. 4. In cold weather moisture may freeze.

Compressed Air Cleaning 1. Don’t use compressed air for cleaning 2. Exception - where reduced to less than 30 p.s.i. with effective chip guarding and PPE 1926.302(b)(4) The 30 p.s.i. requirement does not apply for concrete form, mill scale and similar cleaning purposes.

Powder-Actuated Tools 1. User must be trained and licensed to operate. 2. Test tool each day before loading to ensure the safety devices are working properly. 3. Wear suitable ear, eye, and face protection. 4. Select a powder level that will do the work without excessive force. 1926.302(e)

Easily Penetrated Material Avoid driving into materials easily penetrated unless materials are backed by a substance that will prevent the pin or fastener from passing through. 1926.302(e)(8) Don’t drive fasteners into hard or brittle material that might chip, splatter, or make the fasteners ricochet.

Powder-Actuated Tool “Safety Tips” 1. Don’t use in explosive or flammable atmosphere: 2. Inspect tool before use to ensure: it is clean, do moving parts operate freely the barrel is free from obstructions and has the proper shield, guard, and attachments

Powder-Actuated Tool “Safety Tips” 1. Don’t load the tool unless using immediately. 2. Don’t leave a loaded tool unattended. 3. Keep hands clear of the barrel end. 4. Never point the tool at anyone. 5. Store unloaded in a locked box.

What do the following pictures have in common? 2/16/2019 They all involved hand tools, BUT the right procedures or best work methods were not always followed This slide will run automatically when slide is clicked onto this one is an attention grabber and shock tactics do work extremely well. When the main text is showing click on the space bar to start the injuries sequence. This slide needs to be linked to the finger injuries campaign run last year.it is important to explain to the crews that most tool injuries are to hands and fingers (this is why they are called HAND tools) Please be sure to warn them that there are some graphic pictures on this slide RESULTING IN THIS ! THIS ! OR EVEN THIS !

Hand Tool Injury Prevention 2/16/2019 Hand Tool Injury Prevention Pinch point Incorrect use Correct use (Nice one this) when you click onto the slide the pictures will automatically appear with the text following. Show the top left picture and show the hand position on the hammer this will show you the pinch point that is obvious to all, explain that this was a real LTI on an SDS rig, when the class understands then click mouse to get the actual picture of what injury was sustained. This is the actual picture from the injury. A high proportion of the finger & hand injuries sustained are from the wrong use of hammers. The picture on the left resulted in an LTI.

2/16/2019 Remember This is the final slide and should be read through with some conviction especially emphasizing the stop section Always remember that without hand tools we cannot perform the tasks we do BUT tools can be dangerous so beware! Ask the question how many times have you used tools and pinched your fingers at work or at home?. DO NO BECOME THESE PICTURES!

Worth Keeping

OSHA Regulations Employer Responsibility Wrenches, including adjustable, pipe, end, & socket wrenches, shall not be used when jaws are sprung to the point that slippage occurs.

Basic Hand Tool Safety Guidelines Make sure cutting tools, such as, knives and scissors are adequately sharpened. Wear necessary PPE. Do not use tools around flammable substances where sparks could be a danger – or use spark-resistant tools.

Power Tools - Precautions 1. Disconnect tools when not in use, before servicing, cleaning, & when changing accessories . 2. Keep people not involved with the work away from the work. 3. Secure work with clamps or a vise, freeing both hands to operate the tool. 4. Don’t hold the switch button while carrying a plugged-in tool. 5. Keep tools sharp and clean.

Basic Power Tool “Safety Guidelines” 1. Do NOT wear jewelry or dangling objects that could get caught. 2. Pull back long hair. 3. Attend safety training on the use of tools you have not used before.

Electrocution Warning In certain conditions, even a small amount of current can result in fibrillation of the heart and eventual death. A shock can also cause a fall off a ladder or other elevated surface.

Guarding of Portable Powered Tools 1910.243 All hand-held powered drills, tappers, fastener drivers, horizontal, vertical, & angle grinders or disc sanders with wheels greater than 2 inches in diameter & other similarly operating powered tools shall be equipped with a constant pressure switch or control, & may have a lock-on control provided that turnoff can be accomplished by a single motion of the same finger or fingers that turn it on.

Electrical Power Very popular Usually use 120 V, 1ø power Disadvantages; Must stay connected to power cord. Hazards of electricity Advantages; Unlimited power Many different types of tools. Extension cord must be proper size and in good condition.

Battery Power New technology in batteries has made battery powered tools the first choice for most professionals. Advantages Portability Sealed unit No electrical circuit hazards. Can be used with a wider variety of tools when compared to pneumatic. Disadvantages May be less torque Must have a charged battery to use. Batteries can have a short useable life and are expensive to replace.

Gas Engine Popularity is gaining with the resent invention of lighter weigh engines. The elimination of 2-cycle engines will require a redesign. Disadvantages: Must be used in open environment. Disadvantage of engine maintenance. Safety concerns of gas engines. Usually only large sizes. Advantages: Portability No air hose No extension cords No battery

General Safety Precautions-Electric Tools (cont) When using electric tools; Be aware of several dangers; the most serious is the possibility of electrocution. Among the chief hazards of electric-powered tools are burns & shocks which can lead to injuries or even heart failure.