Section 6.2 Generic hazards
Question 1
Page 1 of 102
,Answer: (a)
Mechinaical Hazards
1. Friction and abraision while contact with fast moving parts and workpiece.
2. Entanglement - when items of clothing, jewellery or hair comes into contact with rotating
parts of the machine.
3. Drawing-in between workpiece and tool rest
4. Ejection of swarf leads to stabbing, puncture.
5. Cut or severing by sharp tools/parts
Non-Mechanical Hazards
1. Electricity by damaged cables / loose contact / earth fault
2. Noise due to process or lack of maintenance
3. High temperature of tools
4. Vibration by the process or lack of maintenance.
5. Hazardous materials such as Saw dust from the process
Answer: (b) (i)
The guard fits around the workplace within which the machine operates and performs several
functions:
It keeps the operators out of the danger area of the machine during normal operation and
prevents contact with dangerous moving parts. Specifically it prevents entanglement with
rotating parts and contact with sharp parts that present a significant cutting / severing
hazard.
It protects the operator from ejected parts such as swarf or fine particles of grinding wheel.
It also offers some protection against the non-mechanical hazards such as:
Noise.
Aerosols - such as cutting fluids used to cool and lubricate the wheel.
Answer: (b) (ii)
Operators of CNC machines have to enter the machine enclosure routinely during normal operations
for:
Cleaning - to remove swarf, dust and other contaminants which may affect normal machine
operation if left in the enclosure.
Setting - configuring the machine into the right position in order for it to start.
Changing tools - CNC machines frequently use multiple tools during routine work.
Changing the workpiece - at the start and end of each work cycle.
Routine inspection of the workpiece and tools is important to check quality and to ensure no
problems are occuring.
Page 2 of 102
,Page 3 of 102
, Answer 2(a)
The mechanical hazards associated with automatic rising arm barrier is Impact by unexpected
movement due to mechanical or sensor failure and shearing and crushing if any body part are
caught in between barrier and arm rest during lowering or free fall of barrier.
Answer 2(b)
Prior to start any maintenance acivity a safe system of work to be developed by considering safe
access or platform for releasing or replacing the components; Use of close fitting overalls to prevent
if any entanglement and drawing-in hazard are present while work with shaft or motor area;
Effective control to be introduced by means of a Permit to work system. This set out in writing all
relevant checks and controls including blocking / rerouting the vehicle routes to protecting workers
from moving traffic that need to be undertaken before work can commence. Then it is necessary to
isolate machinery from potential release of uncontrolled / stored energy sources during
maintenance work.
After isolation and dissipation of hazards, A check should be made to ensure that no hazard remains.
Where control are remote, Security of safety measures at the control station to be ensured by
implementation of lockout tag out system.
When guards are not in place Procedures for working at unguarded machinery by restricting the
use of equipment to those person given the task of using equipment. That person so designated are
specifically trained and competent to deal with particular risk involved.
Page 4 of 102
Question 1
Page 1 of 102
,Answer: (a)
Mechinaical Hazards
1. Friction and abraision while contact with fast moving parts and workpiece.
2. Entanglement - when items of clothing, jewellery or hair comes into contact with rotating
parts of the machine.
3. Drawing-in between workpiece and tool rest
4. Ejection of swarf leads to stabbing, puncture.
5. Cut or severing by sharp tools/parts
Non-Mechanical Hazards
1. Electricity by damaged cables / loose contact / earth fault
2. Noise due to process or lack of maintenance
3. High temperature of tools
4. Vibration by the process or lack of maintenance.
5. Hazardous materials such as Saw dust from the process
Answer: (b) (i)
The guard fits around the workplace within which the machine operates and performs several
functions:
It keeps the operators out of the danger area of the machine during normal operation and
prevents contact with dangerous moving parts. Specifically it prevents entanglement with
rotating parts and contact with sharp parts that present a significant cutting / severing
hazard.
It protects the operator from ejected parts such as swarf or fine particles of grinding wheel.
It also offers some protection against the non-mechanical hazards such as:
Noise.
Aerosols - such as cutting fluids used to cool and lubricate the wheel.
Answer: (b) (ii)
Operators of CNC machines have to enter the machine enclosure routinely during normal operations
for:
Cleaning - to remove swarf, dust and other contaminants which may affect normal machine
operation if left in the enclosure.
Setting - configuring the machine into the right position in order for it to start.
Changing tools - CNC machines frequently use multiple tools during routine work.
Changing the workpiece - at the start and end of each work cycle.
Routine inspection of the workpiece and tools is important to check quality and to ensure no
problems are occuring.
Page 2 of 102
,Page 3 of 102
, Answer 2(a)
The mechanical hazards associated with automatic rising arm barrier is Impact by unexpected
movement due to mechanical or sensor failure and shearing and crushing if any body part are
caught in between barrier and arm rest during lowering or free fall of barrier.
Answer 2(b)
Prior to start any maintenance acivity a safe system of work to be developed by considering safe
access or platform for releasing or replacing the components; Use of close fitting overalls to prevent
if any entanglement and drawing-in hazard are present while work with shaft or motor area;
Effective control to be introduced by means of a Permit to work system. This set out in writing all
relevant checks and controls including blocking / rerouting the vehicle routes to protecting workers
from moving traffic that need to be undertaken before work can commence. Then it is necessary to
isolate machinery from potential release of uncontrolled / stored energy sources during
maintenance work.
After isolation and dissipation of hazards, A check should be made to ensure that no hazard remains.
Where control are remote, Security of safety measures at the control station to be ensured by
implementation of lockout tag out system.
When guards are not in place Procedures for working at unguarded machinery by restricting the
use of equipment to those person given the task of using equipment. That person so designated are
specifically trained and competent to deal with particular risk involved.
Page 4 of 102
