Tools are such a common part of our lives that it is sometimes difficult to remember that they may pose hazards. All tools are manufactured with safety in mind, especially power tools, but occasionally an accident may occur before tool-related hazards are recognized.
It is also important to note that safe use of power tools is covered under the Provision and Use of Work Equipment Regulations (PUWER), and as such employers have a legal duty to comply with these regulations when using power tools and other equipment within their organization and that’s why Epoxy Oilserv Nigeria Limited have taken it as a point of duty to write this article informing workmen to learn to recognize the hazards associated with the different types of tools and the safety precautions required to prevent those hazards.
Appropriate Personal Protective Equipment, such as safety goggles or gloves, should be worn for protection from potential hazards that may be encountered while using portable power tools and hand tools.
Table of Contents
- Definition of terms
- What are power tools?
- What are hazards?
- What is risk?
- What are controls?
- Power Tools Hazards
- General precautions for power tools safety to prevent hazards
- Types of power tools
- Precautions/Control measures for power tool safety
- Frequently Asked Questions About Power Tools
Definition of terms
What are power tools?
A power tool is a device that is triggered by an additional power source and mechanism, other than the solely manual labor used with hand tools. The most common types of power tools use electric motors.
Power tools are used in industries, construction sites, garden, for housework tasks such as cooking, cleaning, and around the house for purposes of driving (fasteners), drilling, cutting, shaping, sanding, grinding, routing, polishing, painting, heating and more.
What are hazards?
A hazard is a source or a situation with the potential for harm in terms of human injury or ill-health, damage to property, damage to the environment, or a combination of these.
Hazards at work may include noisy machinery, a moving forklift, chemicals, electricity, working at heights, a repetitive job, or inappropriate behaviour that adversely affects a worker’s safety and health.
What is risk?
A risk is the chance of something happening that will have a negative effect. The level of risk reflects:
- the likelihood of the unwanted event
- the potential consequences of the unwanted event.
What are controls?
Controls are the measures put in place to decrease the likelihood or consequences from an unwanted event. They can,
- prevent the unwanted event or reduce the loss of control of the hazard (e.g. reduce or contain energy release)
- reduce the effects (e.g. provide a shield from hazard; event has happened but the emergency response and medical treatment reduce the severity and duration of consequences).
Though power tools are a necessity in the workplace because it makes work quicker, and requires less physical effort from the user. However, the benefits they bring also come with hazards/risks because accidents in workplaces can only be controlled, so it is important to consider the safe use of power tools by considering the hazard, risk, and control measures before you start work.
Let’s take a look at the types ,hazards and control measures for power tools.
Power Tools Hazards
- Portable power tools present hazards similar to stationary machines performing the same task.
- Power tools have inherent risk because of its extreme mobility. It can easily come in contact with the operator’s body. At the same time it is difficult to guard such equipment completely.
- Dropping or rough handling can cause tools to inflict injury on the user.
- Hazards of exposure to repetitive vibration/motion (repetitive strain injury)
- Also there are also inherent hazards of the power source.
General precautions for power tools safety to prevent hazards
- Never carry a tool by the cord or hose.
- Never yank the cord or the hose to disconnect it from the receptacle.
- Keep cords and hoses away from heat, oil and sharp edges.
- Disconnect tools when they are not in use, before servicing, and when changing accessories such as blades, bits and cutters.
- All observers should stay a safe distance away from the work area.
- Secure work with clamps or a vise, freeing both hands to operate the tool.
- Avoid accidental starting. The worker should not hold a finger on the switch button while carrying a plugged-in tool. Tools which have lock-on controls should be disengaged when power is interrupted so that they do not start up automatically upon restoration of power.
- Tools should be maintained with care and kept sharp and clean for best performance. Instructions in the user’s manual should be followed for lubrication and changing accessories.
- Workers should assure they have good footing and balance when using power tools. Appropriate apparel should be worn, as loose clothing, ties or jewellery can become caught in moving parts.
- All portable electric tools that are damaged shall be removed from use and tagged “Do Not Use” to prevent electrical shock.
There are several types of power tools, usually categorized according to the power source (electric, pneumatic, liquid fuel, hydraulic, steam and explosive powder actuated) and these Power tools can be hazardous when improperly used thats why its is important for employees to be qualified or trained in the use of all power tools used in their work.
Power tools present hazards such as noise, vibration, electrical, moving parts and projectiles. They have the power to cause severe and even fatal injury if used incorrectly.
Precautions/Control measures for power tool safety
The following safety precautions apply for all portable power tools- electrical, pneumatic, hydraulic etc which are covered :
- All portable power tools shall be equipped with spring-loaded switch (dead man switch) which will actuate only when pressed. The switch shall be free from any locking.
- Users shall always disconnect the tool from the power source before maintenance and attaching accessories. Put guard back in place before reuse and isolate power when not in use.
- User shall secure the tool in elevated places, so that it will not fall if the cord or hose is disconnected.
- Avoid excessive force to make cutting tools cut faster. Feed material only as fast as the tool is designed to accept, prevent excessive wear and decreased control.
- The tools should be suspended to avoid falling on the tool operator, when in working overhead position.
- Cords(double rubber insulated type) and hoses should be laid safely to avoid damage and tripping hazards. Avoid laying cords or hoses over sharp surfaces.
- Braided extension cables shall be used for all power tools to reduce the possibility of damage due to site conditions which could lead to electrocution.
- Avoid accidental starting by ensuring the tool is turned off before it is plugged in. Also do not walk around with a plugged-in tool with the finger touching the switch. Whenever a power tool is to be kept unattended even for a short period, its power supply shall be turned off.
- Use clamps, a vice or other devices to hold and support the piece being worked on, when practical to do so. This will allow the user to use both hands for better control of the tool and will help prevent injuries if a tool jams or binds in a work piece.
- Follow good housekeeping practices – keep the work area free of clutter and debris that could be tripping or slipping.
- Never use power tools with malfunctioning switches or parts.
- Do not walk on or allow vehicles or other moving equipment to pass over unprotected power cords. Cords should be put in conduits or protected by placing planks on each side.
- Connections shall not be taken over water logged areas.
- Do not surprise or touch anyone who is operating a tool. Startling a tool operator could end up causing an accident.
- Only use accessories recommended by the manufacturers. Read the tool manufacturer’s manual to understand the tool’s proper applications, limitations, operation and control.
- Use the right tool for the job. Ensure it is the right size and has sufficient power to do the job safely.
- Select low-vibrating tools as far as possible. Choose tools with vibration-absorbing handles, like those covered with cork, rubber, plastic or plastic bonded to steel.
- Choose hand tools that have the center of gravity within or close to the handle.
- Select tools with rounded and smooth handles that can be gripped easily.
- If they are available, choose hand tools with double handles to permit easier holding and better manipulation of the tool.
- Keep good balance and proper footing at all times. This will help operators to control the tool better, especially in response to unexpected accidents.
- Rest the hands by putting the tool down when not in use.
- Reduce power to the lowest setting that can complete the job safely.
Frequently Asked Questions About Power Tools
- What features must a power tool have before considered safe for use?
According to Occupational Safety and Health Administration (OSHA) Power tools must be fitted with guards and safety switches; they are extremely hazardous when used improperly.
Hazardous moving parts of power tools need to be safeguarded. For example, belts, gears, shafts, pulleys, sprockets, spindles, drums, flywheels, chains or other reciprocating, rotating or moving parts of equipment must be guarded if such parts are exposed to contact by workers. Where necessary, guards should be provided to protect the operator and others with respect to hazards associated with:
- the point of operation
- in-running nip points
- rotating and reciprocating parts
- flying chips and sparks, and mist or spray from metal-working fluids.
Safety guards must never be removed when a tool is being used. For example, portable circular saws must be equipped with guards. An upper guard must cover the entire blade of the saw. A retractable lower guard must cover the teeth of the saw, except when it makes contact with the work material. The lower guard must automatically return to the covering position when the tool is withdrawn from the work.
Safety Switches and Controls
The following are examples of hand-held power tools which must be equipped with a momentary contact “on-off” control switch:
- drills, tappers and fastener drivers
- horizontal, vertical and angle grinders with wheels larger than 2 inches (5.1 cm) in diameter
- disc and belt sanders
- reciprocating and sabre saws.
- What are the hazards and precautions of using an electrical power tool?
Workers using electric tools must be aware of several dangers. The most serious of these is the possibility of electrocution, followed by burns and slight shocks. Under certain conditions, even a small amount of current can result in fibrillation of the heart which may result in death. A shock also may cause a worker to fall off a ladder or other elevated work surfaces.
To reduce the potential of injury to workers from shock, tools must be protected by at least one of the following means:
- Grounded by a three-wire cord (with a ground wire). Three-wire cords contain two current-carrying conductors and a grounding conductor. One end of the grounding conductor connects to the tool’s metal housing. The other end is grounded through a prong on the plug. 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 should never be removed from the plug.
- Double insulated. The worker and the tools are protected in two ways: (1) by normal insulation on the wires inside, and (2) by a housing that cannot conduct electricity to the operator in the event of a malfunction.
- Powered by a low-voltage isolation transformer.
- Connected through ground fault circuit interrupters. These are permanent and portable devices which instantaneously disconnect a circuit when it seeks ground through a worker’s body or through grounded objects.
These general safety practices should be followed in using electric tools:
- Electric tools should be operated within their design limitations.
- Gloves and safety footwear are recommended during use of electric tools.
- When not in use, tools should be stored in a dry place.
- Tools should not be used if wires or connectors are frayed, bent or damaged.
- Electric tools should not be used in damp or wet locations.
- Work areas should be well lighted.
3. I recently purchased a pneumatic power tool which control measures should I take?
Pneumatic tools are powered by compressed air and include chippers, drills, hammers, and sanders. There are several dangers associated with the use of pneumatic tools.
First and foremost is the danger of getting hit by one of the tool’s attachments or by some kind of fastener the user is using.
1.Pneumatic tools must be checked to see that the tools are fastened securely to the air hose to prevent them from becoming disconnected. A short wire or positive locking device attaching the air hose to the tool must also be used and will serve as an added advantage.
2.If an air hose is more than 1/2-inch (12.7 millimeters) in diameter, a safety excess flow valve must be installed at the source of the air supply to reduce pressure in case of hose.
3. Pneumatic tools that shoot nails, rivets, staples, or similar fasteners and operate at pressures more than 100 pounds per square inch(689 kPa), must be equipped with a special device to keep fasteners from being ejected, unless the muzzle is pressed against the work surface.
4.Airless spray guns that atomize paints and fluids at pressures of 1,000 pounds or more per square inch (6,890 kPa) must be equipped with automatic or visible manual safety devices that will prevent pulling the trigger until the safety device is manually built.
5.In general, the same precautions should be taken with an air hose that are recommended for electric cords, because the hose is subject to the same kind of damage or accidental striking, it also presents tripping which is dangerous.
6.Air hoses shall be coupled, locked and secured from undesired movement before opening the air supply valve. A safety clip or retainer must be installed to prevent attachments such as chisels on a chipping hammer from being ejected during tool operation.
7.Eye protection is required, and head and face protection shall be worn by employees working with pneumatic tools. A face shield also shall be used in addition to safety.
8.Screens must also be set up to protect nearby workers from being struck by flying fragments around chippers, riveting guns, staplers, or air.
9.Noise is another hazard associated with pneumatic tools. Working with noisy tools such as jackhammers requires proper, effective use of appropriate hearing protection.
10.Good quality air hoses with proper pressure rating and standard coupling with locking arrangement shall be used. Supply air pressure shall not exceed the design pressure of the tool and accessories.
11.Air hoses shall be inspected for soundness before use. It shall be periodically tested as per manufacturer’s instruction.
12.Air hose should not be used for cleaning dust on machines
13.Before disconnecting the air hose, the supply valve shall be turned off.
14.Make sure that hose connections fit properly and are equipped with a mechanical means of securing the connection (e.g chain, wire, or positive locking device).
15.While working in inert atmosphere nitrogen driven pneumatic tools shall be used.
- How can I differentiate between a hydraulic tool and other tools?
Hydraulic tools are high-powered tools that use pressurized fluid to operate hydraulic machinery. The fluid moves through hydraulic tubes and into the tool’s actuator, where the pressure stored in the fluid is transferred to the machine’s moving parts. Then the fluid is channeled back via a pumping mechanism to be re-pressurized. Hydraulic tools are strong, portable, and flexible enough for use in a variety of applications. Many hydraulic tools can be hooked up to a hydraulic power unit or connected to the hydraulic system of a larger piece of equipment. Metro Hydraulic distributes and services hydraulic tools for myriad industrial purposes.
The fluid used in hydraulic power tools must be an approved fire-resistant fluid and must retain its operating characteristics at the most extreme temperatures to which it will be exposed.
The manufacturer’s recommended safe operating pressure for hoses, valves, pipes, filters and other fittings must not be exceeded.
All jacks – lever and ratchet jacks, screw jacks and hydraulic jacks – must have a device that stops them from jacking up too high. Also, the manufacturer’s load limit must be permanently marked in a prominent place on the jack and should not be exceeded.
A jack should never be used to support a lifted load. Once the load has been lifted, it must immediately be blocked up.
Use wooden blocking under the base if necessary to make the jack level and secure. If the lift surface is metal, place a 1-inch-thick hardwood block or equivalent between it and the metal jack head to reduce the danger of slippage.
To set up a jack, make certain of the following:
- the base rests on a firm level surface,
- the jack is correctly centered,
- the jack head bears against a level surface, and
- the lift force is applied evenly.
Proper maintenance of jacks is essential for safety. All jacks must be inspected before each use and lubricated regularly. If a jack is subjected to an abnormal load or shock, it should be thoroughly examined to make sure it has not been damaged.
Hydraulic jacks exposed to freezing temperatures must be filled with an adequate antifreeze liquid.
Safety practices should be followed in using Hydraulic power tools
- Use only suitable fluid that will retain its characteristics at the highest temperatures.
- Do not exceed the manufacturer’s recommended operating pressure for any reason.
- Hose assemblies must be inspected prior to each use. Worn out fittings, attachment devices, hose and accessory items must be replaced.
- All hose assemblies are tested in accordance with the hose manufacturer’s specifications. The application determines the regularity of the re-testing schedule.
- Retaining devices (safety devices) such as clips, cables or chains must be used. Clamps must be checked regularly under no circumstance should any coupling be disconnected while under pressure unless the coupling is specifically designed to do.
- Disconnecting couplings under pressure could result in serious injury or death, and destruction to property and equipment. Hence ensure that the pressure is fully released while disconnecting couplings under pressure.
- Any leaks on a hydraulic circuit shall be rectified immediately as per manufacturer’s recommendation.
- Oil & lubricants shall be stored as per the manufacturer’s instructions. Monitor the shelf life of oil and lubricants, never use expired items.
5.What are the safety measures for Powder actuated tools?
Powder-actuated tools operate like a loaded gun and should be treated with the same respect and precautions. In fact, they are so dangerous that they must be operated only by specially trained employees.
Safety precautions to remember include the following:
- These tools should not be used in an explosive or flammable atmosphere.
- Before using the tool, the worker should inspect it to determine that it is clean, that all moving parts operate freely, and that the barrel is free from obstructions.
- The tool should never be pointed at anybody.
- The tool should not be loaded unless it is to be used immediately. A loaded tool should not be left unattended, especially where it would be available to unauthorized persons.
- Hands should be kept clear of the barrel end. To prevent the tool from firing accidentally, two separate motions are required for firing: one to bring the tool into position, and another to pull the trigger. The tools must not be able to operate until they are pressed against the work surface with a force of at least 5 pounds greater than the total weight of the tool.
- If a powder-actuated tool misfires, the employee should wait at least 30 seconds, then try firing it again. If it still will not fire, the user should wait another 30 seconds so that the faulty cartridge is less likely to explode, than carefully remove the load. The bad cartridge should be put in water.
Suitable eye and face protection are essential when using a powder-actuated tool.
The muzzle end of the tool must have a protective shield or guard centered perpendicularly on the barrel to confine any flying fragments or particles that might otherwise create a hazard when the tool is fired. The tool must be designed so that it will not fire unless it has this kind of safety device.
All powder-actuated tools must be designed for varying powder charges so that the user can select a powder level necessary to do the work without excessive force.
If the tool develops a defect during use it should be tagged and taken out of service immediately until it is properly repaired.
When using powder-actuated tools to apply fasteners, there are some precautions to consider. Fasteners must not be fired into material that would let them pass through to the other side. The fastener must not be driven into materials like brick or concrete any closer than 3 inches to an edge or corner.
In steel, the fastener must not come any closer than one-half inch from a corner or edge. Fasteners must not be driven into very hard or brittle materials which might chip or splatter, or make the fastener ricochet.
An alignment guide must be used when shooting a fastener into an existing hole. A fastener must not be driven into a spalled area caused by an unsatisfactory fastening.
It is mandatory for workers who use hand and power tools and who are exposed to the hazards of falling, flying, abrasive and splashing objects and materials, or to hazards of harmful dusts, fumes, mists, vapours or gases, must be provided with the appropriate personal equipment necessary to protect them from the hazard. All hazards involved in the use of power tools can be prevented by workers following the basic safety rules stated in this content such as, keep all tools in good condition with regular maintenance,
use the right tool for the job, examine each tool for damage before use, operate tools according to the manufacturer’s instructions and select and use appropriate protective equipment.
It is important to note that employees and employers have a responsibility to work together to maintain established safe work practices and if an unsafe tool or hazardous situation is encountered, it should be brought to the attention of the proper individual immediately.