Hand and power tools have become vital components in nearly all tasks we do. Their widespread use both on and off the job dictates the need for safe practices to prevent injury to ourselves and others in the work area. We need to be aware of the hazards associated with these tools. Training therefore is essential in the correct use of hand and power tools. Maintenance professionals and technicians responsible for specifying and using power tools have a responsibility to check out a tool's safety features, then ensure that manufacturer safety precautions and common sense are followed at all times. Things to Do Before Training Have on hand an electrical power tool that‘s used on the job site and any protective equipment that should be worn while using it (e.g., eye or hearing protection). Read the manufacturer's instructions for the tool, if available. Bring any examples you have of power tools or cords that should not be used because they are unsafe.
QUESTIONS TO ASK Have you or anyone you know had an injury or “near miss”while working with power tools? What happened? What could have been done to prevent it? What are other injuries that could occur when using power tools? Which electrical tools are we using on this job? Have you seen any problems with them? What should you check before turning on a tool [hold up tool] ? What shortcuts that could pose a safety hazard should we avoid when using power tools? What protective gear should we wear when using this tool?
The Specific requirements of the 2007 General Application Regulations (Section 81) on portable electrical equipment are: (1) An employer shall ensure that— (a) a circuit supplying portable equipment or a socket outlet intended to supply portable equipment, including any circuit supplied by an electrical generator, and in which is used alternating current at a voltage— (i) exceeding 125 volts, and (ii) not exceeding 1,000 volts, is protected by one or more residual current devices having a tripping current not exceeding 30 milliamperes operating within such period of time so as to provide the necessary protection to prevent danger to any person coming into direct or indirect contact with any live part of the circuit, (b) portable equipment is maintained in a manner fit for safe use, and (c) portable equipment which is— (i) exposed to conditions causing deterioration liable to result in danger, and (ii) supplied at a voltage exceeding 125 volts alternating current, is— (I) visually checked by the user before use, and (II) periodically inspected by a competent person, appropriate to the nature, location and use of the equipment. (2) An employer shall ensure, where appropriate, that a competent person— (a) tests any portable equipment described in paragraph (1)(c)(i) and (ii), and (b) certifies whether or not the portable equipment (including any cables and plugs) was, on the day of test, as far as could reasonably be ascertained, safe and without risk to persons coming into direct or indirect contact with any live part of the equipment. (3) If the certificate of the competent person referred to in paragraph (2) indicates that the portable equipment tested was not, on the day of the test, safe and without risk, as described in that paragraph, the employer shall ensure that the equipment is not used until it is made safe and certified as such in compliance with paragraph (2). (4) An employer shall ensure that— (a) portable equipment, other than portable transformers and portable generators, supplied at a voltage exceeding 125 volts alternating current is not used in— (i) construction work, (ii) external quarrying activities, or (iii) damp or confined locations, unless its rating exceeds 2 kilovolt amperes, (b) portable hand lamps supplied at a voltage exceeding 25 volts alternating current or 50 volts direct current is not used in— (i) construction work, (ii) external quarrying activities, or iii) damp or confined locations, and (c) where a transformer or generator is used to supply electricity to portable equipment at a voltage greater than 25 volts, but not exceeding 125 volts, alternating current, (i) the centre point, electrically, or (ii) neutral (star) point in the case of three phase of the output voltage or secondary winding, is connected to earth and the transformer or generator is of the double wound type.
We all understand the reasons why safety is so important when it comes to operating power tools. The risk of an accident is very possible. Thousands of minor and major accidents are reported each year with power tools. There are even some reports of death as a result. You can help reduce your chances of being involved in a power tool accident by using each one only for intended uses as outlined by the manufacturer. You should also heed their recommendations for the proper safety equipment to use while you are operating a particular power tool. The most common power tool accidents involve injuries to the fingers. This can be anything from a minor cut to losing the entire finger. Power tools can also contribute to “ergonomic” injuries. These are injuries to the muscles, tendons, joints, and nerves. They include strains and sprains, tendinitis, and carpal tunnel syndrome. Ergonomic injuries can happen right away or develop over time.
A large portion of power tool injuries occur because the power source is not removed while changing parts on the power tool. It doesn’t matter how much experience you have with the power tool or how quickly you can change the part. Drill bits and saw blades are the most common culprits. It only takes a moment to unplug the power source. If you are using a cordless power tool, you may want to remove the battery before you change anything on it. The inconvenience is worth your safety. Cords on power tools are another concern. Many power tool accidents have been eliminated by going to cordless power tools. If you operate any type of power tool that has a cord, make sure you have it properly secured. Don’t leave the cord out in the open where you or someone else can trip on it. There is the risk of electrocution so make sure the cords aren’t frayed. This includes an extension cords you may be using as well. Keep the cords out of wet, damp areas, and make sure there is nothing in the area that can accidentally be spilled on them. Even if you use the power tool as it should be operated and have on the right safety equipment, accidents can still happen in the blink of an eye. Tripping, slipping, or falling while you have a power tool in your hand can result in an injury. One unfortunately young man was using a staple gun on a ladder with safety equipment on when he lost his footing. He fell from the ladder and ended up with several long nails in his skull. He didn’t die from it but could have. To help prevent power tool accidents, make sure your work area is secure. Ladders should be securely in place. Never work on a surface that is slippery or unstable. It is a risk you don’t want to be taking with a power tool in your hand. I understand that not all work areas are under the best of circumstances. Be cautious and use common sense. This information isn’t meant to scare you, only to help you remember that power tools are dangerous, and you have to use them responsibly. Hopefully all of your experiences with power tools with be safe. Do your part to use them under the best possible conditions to help reduce the amount of power tool accidents out there. Online videos are available at www.sawstop.com
An example of specific power tool hazards, this is a good time to talk about the specific power tools in your workplace and their hazards. Use a flip chart or white board and get trainees to identify hazards associated with their tools. Use the Power Tool Institute – Safety is Specific Handbook for more information on specific power tools and their hazards. This could be provided as a handout to participants and sections relevant to the workplace tools consulted during the training.
During this section it is a good idea to demonstrate the use of and discuss safe practice of the tools use din your workplace.
Belt sanding machines must be provided with guards at each nip point where the sanding belt runs onto a pulley .
Equip with guards that: Cover the spindle end, nut, & flange projections Maintain proper alignment with the wheel Don’t exceed the strength of the fastenings Guard so that a minimal amount of the wheel is exposed
A 22-year-old carpenter’s apprentice was killed when he was struck in the head by a nail fired from a powder-actuated nail gun. The nail gun operator fired the gun while attempting to anchor a plywood concrete form, causing the nail to pass through the hollow form. The nail traveled 27 feet before striking the victim. The nail gun operator had never received training on how to use the tool, and none of the employees in the area was wearing PPE. In another situation, two workers were building a wall while remodeling a house. One of the workers was killed when he was struck by a nail fired from a powder-actuated nail gun. The tool operator who fired the nail was trying to attach a piece of plywood to a wooden stud. But the nail shot though the plywood and stud, striking the victim. Employees using powder- or pressure-actuated tools must be trained to use them safely. Employees who operate powder- or pressure-actuated tools must be trained to avoid firing into easily penetrated materials (like plywood). In areas where workers could be exposed to flying nails, appropriate PPE must be used.
Saws account for a large share of power tool accidents. The very nature of high-speed, super-sharp blades can produce severe injuries. Base your safety training on two central points: the potential hazards and how to avoid injury. A well-proven fact in the use of saws and other cutting tools is that guards are critical to safety. Modern guards provide essential protection without hindering the tool's capacity to do its job in any way. If your students have been told otherwise, they've been dangerously misinformed. It's vital that you correct them. Properly functioning guards respond to emergencies by providing an immediate barrier between the operator and high-speed cutting edges. They also serve to contain sawdust, chips and other debris that can be thrown toward the operator. They simply must be used for each and every operation. Yet, the use of guards alone is not enough. Guards must still be combined with proper setup and tool operation to assure the operator's safety . One of the most serious issues in learning to use power saws is averting kickback. The table saw and radial arm saw are two of the most widely used power tools in any woodworking shop — and two of the most demanding. Operators must have a thorough understanding of these tools and all their procedures in addition to knowing how to set up for safety. The area around the blades of the table and radial arm saws can generally be considered a &quot;danger zone.&quot; Any time any part of the operator's body comes in direct line with the blade, or is less than three inches to either side of the blade, that operator is in imminent danger. Remember that no power tool knows the difference between a workpiece and flesh and bone. Show your students how to avoid awkward operations and hand positions that might allow the operator's hands to move into the cutting tool. Help them develop the habit of always avoiding the area in front of the blade and three inches to each side. Tell them to never reach behind or over the blade for any reason. Teach them that when the operator's hands need to pass beyond the front edge of the saw table or past the leading edge of the blade, he or she must use work helpers to keep the workpiece flat on the table and against the fence. Show your students how work helpers will help stabilize, control and guide the workpiece while allowing the operator better cutting precision without placing hands and arms in harm's way. Make sure your students understand that time invested in careful and proper setup using work helpers is all important to safety — and actually saves time, too.
Long hair – risk of entanglement.
Questions to Ask: Do you have any other concerns about portable power tools? Do you see any problems on our job? What about other jobs you’ve worked on? Have you had any experience with portable power tools that might help us work safer on this job?
Fuses - The prime objective of a fuse is to protect equipment or an installation from overheating and becoming a fire hazard. It is not an effective protection against electric shock due to the time that it takes to cut the current flow. Fuse has a ‘fuseable’ wire element which heats up when current flows . Excessive current = excessive heat & wire melts preventing current flow Earthing - creates a low-resistance path from a tool to the earth to disperse unwanted current. Grounded electrical systems are usually connected to a grounding rod that is placed 6-8 feet deep into the earth. Grounded - connected to earth or to some conducting body that serves in place of the earth. Isolation - involves more than 'switching off' the current in that the circuit is made dead and cannot be accidentally re-energized. It creates a barrier between the equipment and the electrical supply which only an authorized person should be able 10 remove. Before earthing or working on an isolated circuit, checks must be made to ensure that the circuit is dead and that the isolation switch is 'locked off' and clearly labeled. Reduced low voltage systems - When the working conditions are relatively severe either due to wet conditions or heavy and frequent usage of equipment, reduced voltage systems should be used. All portable tools used on construction sites, vehicle washing stations or near swimming pools, should operate on 110 V or less, preferably with a centre tapped to earth at 55 V. At this level of voltage, the effect of any electric shock should not be severe. Another way to reduce the voltage is to use battery (cordless) operated hand tools. Residual current devices - RCDs, also known as earth leakage circuit breakers, monitor and compare the current flowing in the live and neutral conductors supplying the protected equipment. Such devices will cut the supply to the equipment in a very short period of time when a difference of only a few milliamperes occurs. RCDs for protecting people have a rated tripping current (sensitivity) of not more than 30 milliamps (mA). An RCD is a valuable safety device, never bypass it. If the RCD trips, it is a sign there is a fault. Check the system before using it again. If the RCD trips frequently and no fault can be found in the system, consult the manufacturer of the RCD. The RCD has a test button to check that its mechanism is free and functioning. Use this regularly Insulation: Index of Protection (IP) rating system indicates degree of protection given.
Electric shock is the convulsive reaction by the human body to the flow of electrical current through it. This sense of shock is accompanied by pain and, in more severe cases, by burning. The shock can be produced by low voltages, high voltages or lightning. Most incidents of electric shock occur when the person becomes the route to earth for a live conductor. The effect of electrical shock and the resultant severity of injury depend upon the size of the electrical current passing through the body which, in turn, depends on the voltage and the electrical resistance of the skin. If the skin is wet, a shock from mains voltage (220/240 V) could well be fatal. The effect of shock is very dependent on conditions at the time, but it is always dangerous and must be avoided. Electrical burns are usually more severe than those caused by heat, since they can penetrate deep into the tissues of the body. The effect of electric current on the human body depends on its pathway through the body (e.g. hand to hand or hand to foot), the frequency of the current, the length of time of the shock and the size of the current.
There are many excellent posters available which illustrate the first-aid procedure for treating electric shock and such posters should be positioned close to electrical junction boxes or isolation switches. An electrical current of 1 mA is detectable by touch and one of 10 mA will cause muscle contraction, which may prevent the person from being able to release the conductor, and if the chest is in the current path, respiratory movement may be prevented causing asphyxia. Current passing through the chest may also cause fibrillation of the heart (vibration of the heart muscle) and disrupt the normal rhythm of the heart, though this is likely only within a particular range of currents. The shock can also cause the heart to stop completely (cardiac arrest) and this will lead to the cessation of breathing. Current passing through the respiratory centre of the brain may cause respiratory arrest that does not quickly respond to the breaking of the electrical contact. These effects on the heart and respiratory system can be caused by currents as low as 25 mA. It is not possible to be precise on the threshold current because it is dependent on the environmental conditions at the time, as well as the age, sex, body weight and health of the person. Burns of the skin occur at the point of electrical contact due to the high resistance of skin, these burns may be deep, slow to heal and often leave permanent scars. Burns may also occur inside the body along the path of the electric current causing damage to muscle tissue and blood cells.
Typical poster found in the workplace near electrical installations.
Shock-related injuries include burns, internal injuries, and injuries due to involuntary muscle contractions. The most common shock-related injury is a burn. Burns suffered in electrical incidents may be one or more of the following three types. Electrical burns cause tissue damage, and are the result of heat generated by the flow of electrical current through the body. These are one of the most serious injuries you can receive and require immediate attention. Arc or Flash burns are caused by high temperatures near the body produced by an electrical arc or explosion. Attend to them immediately. Thermal contact burns occur when skin comes in contact with overheated electric equipment, or when clothing is ignited by an electrical incident.
Short circuits happen if insulation becomes faulty and an unintended flow of current between two conductors or between one conductor and earth occurs. The amount of the current depends upon the voltage, the condition of the insulating material and the distance between the conductors. At first the current flow will be low but as the fault develops the current will increase and the area surrounding the fault will heat up If the fuse fails to operate or is in excess of the recommended fuse rating, overheating will occur and a fire will result. A fire can also be caused if combustible material is in close proximity to the heated wire or hot sparks are ejected. Short circuits are most likely to occur where electrical equipment or cables are susceptible to damage by water leaks or mechanical damage. Twisted or bent cables can also cause breakdowns in insulation materials. Inspection covers and cable boxes are particularly problem areas. Overheating of cables and equipment will occur if, they become overloaded. Electrical equipment and circuits are normally rated to carry a given safe current which will keep the temperature rise of the conductors in the circuit or appliance within permissible limits and avoid the possibility of fire. These safe currents define the maximum size of the fuse (the fuse rating) required for the appliance. A common cause of circuit overloading is the use of equipment and cables which are too small for the imposed electrical load. Another cause of overloading is mechanical breakdown or wear of an electric motor and the driven machinery. Motors must be maintained in good condition with particular attention paid to bearing surfaces. Loose cable connections are one of the most common causes of overheating and may be readily detected (as well as overloaded cable) by a thermal imaging survey. The bunching of cables together can also cause excessive heat to be developed within the inner cable leading to a fire risk. This can happen with cable extension reels, which have only been partially unwound, used for high-energy appliances like an electric heater. Ventilation is necessary to maintain safe temperatures in most electrical equipment and overheating is liable to occur if ventilation is in any way obstructed or reduced.
What is occupational vibration? Occupational vibration can be divided into two areas, HAV, H and A rm V ibration, and WBV, W hole B ody V ibration. HAV is associated with hand held power tools where the vibration is transmitted from the work process into the workers hands and arms. WBV is a form of mechanical vibration transmitted through a supporting surface to the operators body, such as through the seat of a vehicle or a vibrating floor surface. Research studies have demonstrated that vibration is a significant physical hazard in the work place and that exposure to hand-arm or whole-body vibration has the potential to inflict both short and long term physical damage. New EU Regulations with significant legal obligations on management of vibration hazards in the workplace were implemented in Ireland in 2006 and now form part of the General Application Regulations 2007. In addition, compensation for vibration related injuries continue to escalate making it fiscally responsible for employers to take a proactive approach to monitoring and eliminating vibration hazards in the workplace.
Hand-arm vibration syndrome can be known as Raynaud's phenomenon of occupational origin. Vibration is just one cause of Raynaud's phenomenon. Other causes are connective tissue diseases, tissue injury, diseases of the blood vessels in the fingers, exposure to vinyl chloride, and the use of certain drugs. The resulting reduced blood flow can produce white fingers in cold environments.
Vibration exposure is possible in many occupations where a worker comes in contact with vibrating machinery or equipment.
Before you buy new equipment, consider any alternative way of working without using vibrating equipment. If not, introduce a low vibration purchasing policy in consultation with your managers and safety or employee representatives and let potential suppliers know about it. You should aim to buy the lowest vibration equipment suitable for the job. Manufacturers identify vibration levels in units of meters per second squared (m/s 2 ).
Vibration-induced white finger (VWF) is the most common condition among the operators of hand-held vibrating tools. Vibration can cause changes in tendons, muscles, bones and joints, and can affect the nervous system. Collectively, these effects are known as Hand-Arm Vibration Syndrome (HAVS). The symptoms of VWF are aggravated when the hands are exposed to cold.
Hand-arm vibration exposure affects the blood flow (vascular effect) and causes loss of touch sensation (neurological effect) in fingers. The development of HAVS is gradual and increases in severity over time. It may take a few months to several years for the symptoms of HAVS to become noticeable. At first, hand-arm vibration syndrome can cause a tingling sensation, or “pins and needles ”in the fingers, maybe with some numbness. This will usually happen at the end of a day working with vibrating equipment or sometimes when conditions are cold or wet. As the condition gets worse, symptoms may be triggered by the cold, without using vibrating equipment. The fingers will become white and numb, initially just the tips, but the area can get larger if you continue to work with high-vibration equipment. As blood circulation returns, the fingers may get a red flush and become painful. In worse cases, pain, stiffness and difficulty in handling small items can last for up to an hour and be triggered by any exposure to mild cold for example when washing the car or fishing. In 1986, a classification, known as Stockholm classification was introduced. In this classification, vascular (blood flow) changes and neural (feeling of touch, heat, cold, etc.) changes are considered separately.
The severity of hand-arm vibration syndrome depends on several other factors, such as the characteristics of vibration exposure, work practice, personal history and habits. UK HSE estimates that there are around 36 000 people with an advanced stage of vibration white finger (VWF), which is the most well known form of hand-arm vibration syndrome. The UK Medical Research Council (MRC) survey in 1997-98 gave a prevalence estimate of 288'000 sufferers from vibration white finger (VWF) in Great Britain (255'000 males and 33'000 females respectively). The industry group with by far the highest average rate of new assessments of disability in 2000-2003 was extraction energy and water supply, due to the relatively large number of claims made by current or former coal miners. Coal miners in general seem to be more aware than workers in other industries of the possibility of claiming compensation, due to the efforts of trade unions to make them aware, and the publicity given to civil litigation concerning VWF in miners. Such influences probably explain, at least in part, why such a high proportion of officially recognized VWF cases come from this one industry. Other industry groups with high rates of new assessed cases are construction (13.6 cases per 100 000 employees), manufacturing (7.4), and agriculture forestry and fishing (3.3) - not surprisingly since these groups include industries where there is substantial use of vibrating tools.
Conventional protective gloves (e.g., cotton, leather), commonly used by workers, do not reduce the vibration that is transferred to workers ’ hands when they are using vibrating tools or equipment. Anti-vibration gloves are made using a layer of viscoelastic material. Actual measurements have shown that such gloves have limited effectiveness in absorbing low-frequency vibration, the major contributor to vibration-related disorders. Therefore, they offer little protection against developing vibration-induced white finger syndrome. However, gloves do provide protection from typical industrial hazards (e.g. cuts, abrasions) and from cold temperatures that, in turn, may reduce the initial sensation of white finger attacks.
Employees who use hand and power tools and who are exposed to the hazards of falling, flying, abrasive and splashing objects, or exposed to harmful dusts, fumes, mists, vapors, or gases must be provided with the particular personal equipment necessary to protect them from the hazard. 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. Show & discuss samples of PPE used at your workplace during the following slides.
Eye hazards vary depending on the type of work you do, but these are the main categories.
“ Other activities include drilling, sanding, cutting, chiseling, sawing or any other use of power tools that generates dust or particles. Most of us have gotten dust or dirt in our eyes at one time or another which was easily removed with little permanent damage. But sometimes the injury can be severe enough to require medical treatment or even cause permanent damage. 70% of all eye injuries resulted from flying or falling objects or sparks striking the eye.”
ELECTRICIANS, PLUMBERS AND PIPEFITTERS RANK IN THE TOP FIVE TRADES.
Protects against risk of flying objects or dust particles, splashes of hazardous materials or harmful rays.
[List or tell where or from who employees can get replacements for broken, damaged or worn out eye protection.]
“ These noise levels are approximate.”
“ The left picture shows plugs only partially inserted into the ear canal – a common mistake.”
BE SURE TO UNDERSTAND THE DANGERS OR HAZARDS THAT MAY BE CREATED BY THE USE OF PPE BE AWARE OF FALSE SENSE OF SECURITY THAT PPE CAN GIVE DO NOT ALLOW SAFETY STANDARDS TO DROP BECAUSE YOU WEAR IT