Disc cutters, grinders and abrasive wheels

In addition to eye or other injury via operator contact with blades or fast moving rotating machinery, abrasive wheels may 'burst' when operating, or entrap tools. Sparks generated during their use may also provide an ignition source for combustible materials, whilst entanglement of loose clothing may lead to severe injury for operators.

Managing hazards

Management of this hazard requires selection of correct items (wheels, motors etc), routine inspection of their condition, use of guards where required and correct operating practice.

Abrasive wheels in particular require careful attention, due to the risk of injury through 'bursting'. This may arise from uneven wear, grooves, localised heating, imbalance, use of a tapered spindle, 'heavy' use or excessive speed. Side-grinding, and braking of the wheel by contact with the wheel itself are dangerous practices.

Abrasive wheels must be marked with their maximum operating speed (rpm), and only fitted to machines which will not exceed this. Where the maximum operating speed at the periphery is in m/s, the conversion is:

• rotation speed = peripheral speed x 60,000]
• (rpm) _ x diameter (mm)

Work-rests must be placed as close as possible to the wheel, to minimise the risk of tools being 'grabbed' by the wheel.

Enclosures, guards or shields must be used to protect the operator and others from flying objects. Adjustable visors are preferable to personal eye protection as they also offer some protection for the face. Respiratory protection may also be required. Where grinding fluids are used, these must be compatible with the wheel. Never allow a wheel to stand partly immersed in grinding fluid, as this will unbalance it.

Any new wheel must be suitably guarded (protecting all personnel in the vicinity), the work-rest positioned, and the wheel tested at maximum speed for a short period. As a wheel wears, it must be routinely checked, and where necessary, rebalanced.

Dressing tools must be securely clamped wherever possible, rather than being hand held.

For hand held abrasive tools, never use more than one wheel per spindle. Operators must wear close-fitting clothing, tie up long hair and other items which could otherwise become entangled in rotating machinery. Personal eye protection and respiratory protection may also be required.

Emergency Procedures

Removal of a foreign body from the eye should only be done by medical personnel.