Abrasive wheels are used in almost every industry and in a huge range of workplaces. They come in many sizes and shapes and have a wide variety of uses, from sharpening a chisel to cutting through steel plate. They fit a variety of machines, from small hand-held angle grinders to very large industrial grinding and cutting-off machines.

The majority of accidents with abrasive wheels happen because of poor planning, incorrect selection of the wheel and unsafe use. Almost all of them are preventable.

The main safety risk is a wheel breaking or bursting at high speed, usually because it was incorrectly or poorly mounted, run too fast, or damaged before use. Fragments leave a bursting wheel at the speed of a bullet from an air rifle, and the result can be serious injury or death.

There are also health risks that build up over time: unsafe manual handling of heavy wheels and machines, harmful metalworking fluids, breathing in dust and fumes, noise, and Hand-Arm Vibration Syndrome (HAVS) from hand-held machines.

This course explains why everyone who works with abrasive wheels must understand these risks, and the controls that are needed to use abrasive wheels safely.

By the end of this course, you will:

• Be able to identify the main types of abrasive wheels and the machines they are used on, and understand the hazards and risks associated with them.
• Understand the legal duties placed on manufacturers, employers and employees for the safe use of abrasive wheels.
• Know how to carry out a risk assessment for the safe use of abrasive wheels.
• Be aware of the control measures needed to reduce or eliminate the risks, including harmful dust, vibration, noise, fire and electrical risks.
• Understand how to safely handle, store, mount, use, dress and inspect the main types of abrasive wheel.

The topics covered in this module are:

• Types of abrasive wheels and machines
• Dangers of abrasive wheels
• Manufacturers' responsibilities
• Abrasive wheels and the law
• Employer responsibilities
• Employee responsibilities
• HSE guidance

Abrasive wheels are used in grinding and cutting machines, mostly for metalworking. The machines can be fixed, such as a bench or pedestal grinder, or portable, such as an angle grinder. Depending on the type of wheel, they are made and used in different ways.

An abrasive wheel is made of abrasive particles held together by a bonding material. The bond is either inorganic or organic.

Inorganic (vitrified) wheels are fired in a furnace. This makes the wheel hard and strong, but with a brittle, glass-like structure. They hold their shape well and are mostly used for precision grinding on fixed machines. They need regular dressing to remove metal that clogs the surface and to restore the cutting edge.

Organic (resinoid or rubber bonded) wheels are more flexible and can be made very thin. They are the wheels used on angle grinders and portable cutting-off machines.

Every abrasive wheel is defined by its grit size, the abrasive material, the bonding material, the grade (hardness) and the structure (how open or dense it is).

Inorganic wheels are used on many types of fixed grinding machine: bench and pedestal grinders, plain and universal cylindrical grinders, and internal, surface, tool and cutter grinders. Between them these machines use a very wide range of vitrified wheels.

Bench and pedestal grinders are the machines most people meet at work. They are used for sharpening tools, removing burrs and finishing workpieces, usually for short periods by many different people. That is exactly why they are so often neglected.

Hand-held grinding and cutting-off machines, above all the angle grinder, use organic bonded wheels or metal cutting discs. They are used to surface grind, cut and sand components, and they are found in almost every workshop, construction site and maintenance department.

Hand-held machines carry the widest range of risks: they are used in awkward positions, close to the body, often on site rather than in a controlled workshop.

Abrasive wheels are used by a wide variety of industries, but if they are not used safely and correctly they can cause injuries in many ways.

Most injuries from grinding and cutting-off machines are the result of:

• Impact injuries from bursting wheels, which can be fatal.
• Contact with a rotating abrasive wheel, causing deep cuts and abrasions.
• Cutting and crushing injuries from being trapped between the wheel and the work rest.
• Fires and explosions from poor control of grinding dust containing aluminium, magnesium and similar flammable metals.
• Eye injuries from failing to wear eye protection or to use the protective screens fitted to the machine.

Abrasive wheels can also cause serious long-term health problems. Prolonged use without the right controls can leave a worker with lifelong damage, so it is vital to be aware of the risks.

Most ill health arises from:

• Unsafe manual handling of heavy wheels and machines, which can have a lasting effect on the back, shoulders and the wider musculoskeletal system.
• Harmful metalworking fluids, which can cause dermatitis and skin irritation.
• Vibration from hand-held grinding machines, which can cause Hand-Arm Vibration Syndrome (HAVS). Workers may develop 'white finger' and permanent damage to the nerves and blood vessels of the hands and arms.
• Prolonged exposure to the noise of the grinding operation itself, which can result in permanent hearing loss and tinnitus.
• Breathing in the dust and fumes generated, which irritates the airways and can cause both short-term and long-term illness, including occupational asthma, lung disease and cancer.
• Dust and fumes settling on the skin and eyes, causing irritation and eye damage.

There are many risks when using abrasive wheels, but the main safety risk is still that an abrasive wheel can break and cause serious injury or death.

To reduce that risk, anyone who prepares an abrasive wheel, including mounting it on a machine, uses it, dresses it or inspects it, must be trained and competent to do so safely. Mounting is not a job for whoever happens to be nearest.

There are also duties on the manufacturers and suppliers of abrasive wheels and grinding machines. Under section 6 of the Health and Safety at Work etc. Act 1974 and the Supply of Machinery (Safety) Regulations 2008, the equipment they place on the market must be safe for its designed use and must come with the information needed to use it safely.

A UKCA or CE marking on a machine shows that the manufacturer declares it meets the relevant safety requirements. It is a starting point, not a guarantee that the machine is safe in your workplace.

Manufacturers of abrasive wheels are required by law to minimise the risk of breakage and injury. Much of that protection is built into the wheel itself.

These precautions include:

• Fibre reinforcement. Resinoid and rubber bonded organic wheels for heavy-duty grinding and cutting contain a resin-coated woven glass-fibre mat. It makes the wheel stronger and, if the wheel does break in use, holds the fragments together.
• Steel rings moulded into the wheel close to the bore. They limit wear around the hole and are designed to retain fragments if a breakage occurs.
• Safety inserts. These are threaded nuts with locking teeth, forming part of a plate that strengthens the base of a cup wheel used on portable grinders.
• Tape winding. Adhesive tape, glass fibre or metal wire wound around a cylinder wheel helps to hold the fragments together if the wheel breaks.
• A fine-grit centre moulded around the bore of the wheel, which increases its strength where the mounting loads are highest.

While manufacturers are required to supply safe abrasive wheels, wheels do still break in use. Almost every breakage traces back to something that happened after the wheel left the factory.

Breakages can be caused by:

• A defect caused by misuse or rough handling.
• Bad storage, for example damp, heat or wheels left leaning against a wall.
• Incorrect selection of a wheel for the job or the machine.
• Improper mounting.
• Out-of-balance conditions.
• Excessive speed.
• Grinding machine defects, such as worn bearings or a bent spindle.
• Bad practices in grinding, such as side grinding on a straight wheel or forcing the work into the wheel.

A breakage often has more than one cause working together, for example a slightly damaged wheel that was then over-tightened.

It is essential that every abrasive wheel breakage is investigated carefully to establish the cause, and that action is taken to prevent it happening again.

In Great Britain the main legal requirements for abrasive wheels are set out in the Provision and Use of Work Equipment Regulations 1998 (PUWER). PUWER replaced the older Abrasive Wheels Regulations 1970, and it is made under the Health and Safety at Work etc. Act 1974.

The primary objective of these Regulations is to make sure that work equipment, including abrasive wheel machines and the wheels themselves, does not put the health and safety of workers at risk, regardless of the equipment's age, condition or origin.

The Regulations contain a number of separate requirements: the suitability of work equipment for the job, maintenance, inspection, guarding of dangerous parts, protection against specified hazards such as the ejection of parts, controls, stability and lighting, and the marking of equipment.

The Health and Safety Executive (HSE) publishes HSG17, 'Safety in the use of abrasive wheels', together with guidance on PUWER. Following it is the accepted way of showing that you have met your legal duties. If an employer chooses a different approach, it is for the employer to show that it is at least as good.

Regulation 7 of PUWER deals with specific risks from work equipment, and abrasive wheel machines are a clear example.

Where the risks from normal use of a machine cannot be fully controlled by guarding and other measures, the use of that machine must be restricted to the people whose task it is. Those people must have received sufficient information, instruction and training to use it safely.

The same applies to repair, maintenance, servicing and cleaning. Only people who have been given sufficient information, instruction and training to carry out that work safely may do it, and they should be specifically designated for those tasks.

In practice this means a written list of who may mount wheels, who may dress them and who may use each machine, and a way of making sure that nobody outside that list touches them.

The law requires that abrasive wheels are mounted only by people who have been designated and trained for the task. A person cannot be designated until they have been trained.

That training must cover:

• The hazards arising from the use of abrasive wheels and the precautions to be observed.
• The methods of marking abrasive wheels as to type and maximum speed.
• How to store, handle and transport abrasive wheels.
• How to inspect and test abrasive wheels to check for damage, including the ring test.
• The correct method of dressing an abrasive wheel: removing dull abrasive and embedded metal, and keeping wear even.
• How to adjust the work rest of a machine correctly.
• The function of every component used with abrasive wheels, including flanges, blotters, bushes and nuts used in mounting.
• The correct method of assembling all those components so the wheel is properly balanced and fit for use.
• How to select and use the appropriate Personal Protective Equipment (PPE).

Regulation 12 of PUWER requires employers to protect workers against certain specified hazards from work equipment. For abrasive wheels the relevant ones are:

• Any article or substance falling or being ejected from the work equipment, for example a fragment of a bursting wheel or a workpiece thrown out.
• Rupture or disintegration of parts of the work equipment.
• The unintended or premature explosion of the work equipment or of any article or substance produced, used or stored in it, for example flammable grinding dust.

These hazards must be adequately controlled, and the law is explicit that this cannot be done simply by providing PPE and giving information, instruction and training. Employers must first prevent the hazard occurring and, where that is not possible, reduce the likelihood and limit the effects.

For abrasive wheels this means: never exceed the marked speed, fit guards strong enough to contain fragments, keep machines well maintained, control dust, and then provide the information, training and PPE on top.

Other legislation that applies to the use of abrasive wheels includes:

• The Health and Safety at Work etc. Act 1974: the general duties of employers and employees.
• The Management of Health and Safety at Work Regulations 1999: risk assessment.
• The Provision and Use of Work Equipment Regulations 1998 (PUWER).
• The Control of Noise at Work Regulations 2005.
• The Control of Vibration at Work Regulations 2005.
• The Electricity at Work Regulations 1989.
• The Control of Substances Hazardous to Health Regulations 2002 (COSHH), for dust, fumes and metalworking fluids.
• The Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013 (RIDDOR).

Under the Health and Safety at Work etc. Act 1974, every employer must ensure, so far as is reasonably practicable, the health, safety and welfare at work of their employees.

This is a very wide duty. It means that anyone who changes an abrasive wheel, works with one, or is simply nearby when one is being used, must be protected.

The Management of Health and Safety at Work Regulations 1999 also require employers to carry out a 'suitable and sufficient' risk assessment of the hazards in the workplace. For abrasive wheels there must be a risk assessment that covers all of the significant risks and the controls that are in place.

Employers must also provide the information, instruction, training and supervision needed, provide and maintain suitable equipment and guards, and provide PPE where the risk cannot be controlled in any other way.

The next module walks through the risk assessment step by step.

Employees also have legal responsibilities for health and safety. The law places a number of duties on you to protect yourself and the people around you.

As an employee you must:

• Take reasonable care of your own health and safety, and that of anyone else who may be affected by what you do or fail to do.
• Not use an abrasive wheel machine, or mount or dress a wheel, unless you have been trained and authorised to do so.
• Use the machines, guards, extraction and PPE provided, in the way you were trained to use them.
• Not interfere with or misuse anything provided for health and safety, such as removing a guard or disabling a dead man's switch.
• Report to your employer any danger to health and safety from a work activity, and any shortcoming in the protective arrangements, such as a damaged wheel or a missing guard.
• Cooperate fully with your employer's health and safety arrangements, including attending training and following the safe system of work.

The Health and Safety Executive (HSE) publishes free guidance on the safe use of abrasive wheels and on work equipment generally.

The two documents every employer and every trained operator should have to hand are:

• HSE HSG17: Safety in the use of abrasive wheels.
• HSE L22: Safe use of work equipment. Provision and Use of Work Equipment Regulations 1998, Approved Code of Practice and guidance.

Both are available as free downloads from the HSE website, hse.gov.uk. Keep a copy where the grinding machines are used, not just in the office.