Introduction to Health and Safety at Work

Construction – bench-mounted circular saw
The hazards are:
➤
contact with the cutting blade above and below the 
bench
➤
ejection of the work-piece or timber as it closes after 
passing the cutting blade
➤
drawing-in between chain and sprocket or V belt 
drives
➤
contact and entanglement with moving parts of the 
drive motor
➤
likely noise hazards from the cutting action and motor
➤
health hazards from wood dust given off during 
cutting
➤
electric shock from faulty wiring and/or earthing or 
during maintenance.
11.13 
Practical safeguards
PUWER requires that access to dangerous parts of 
machinery should be prevented in a preferred order or 
hierarchy of control methods. The standard required is a 
‘practicable’ one, so that the only acceptable reason for 
non-compliance is that there is no technical solution. Cost 
is not a factor. (See Chapter 1 for more details on stand-
ards of compliance.)
The levels of protection required are, in order of 
implementation:
➤
fi xed enclosing guarding
➤
other guards or protection devices, such as inter-
locked guards and pressure sensitive mats
➤
protection appliances, such as jigs, holders and 
push-sticks and
➤
the provision of information, instruction, training and 
supervision.
Since the mechanical hazard of machinery arises prin-
cipally from someone coming into contact or entangle-
ment with dangerous components, risk reduction is 
based on preventing this contact occurring.
This may be by means of:
➤
a physical barrier between the individual and the 
component (e.g. a fi xed enclosing guard)
➤
a device which only allows access when the com-
ponent is in a safe state (e.g. an interlocked guard 
which prevents the machine starting unless a guard is 
closed and acts to stop the machine if the guard is 
opened) or
➤
a device which detects that the individual is entering 
a risk area and then stops the machine (e.g. certain 
photoelectric guards and pressure-sensitive mats).
The best method should, ideally, be chosen by the 
designer as early in the life of the machine as possible. 
It is often found that safeguards which are ‘bolted on’ 
instead of ‘built in’ are not only less effective in reducing 

---