Introduction to Health and Safety at Work

Work on high voltage apparatus (including testing)
Work on high voltage apparatus (over about 600 volts) is 
potentially high risk. Hazards include:
➤
possibly fatal electric shock/burns to the people 
doing the work
➤
electrical 
fi res/explosions
➤
consequential danger from disruption of power sup-
ply to safety-critical plant and equipment.
In view of the risk, this work must only be done by suit-
ably trained and competent people acting under the 
terms of a high voltage permit.
Hot work
Hot work is potentially hazardous as:
➤
a source of ignition in any plant in which fl ammable 
materials are handled
➤
a cause of fi res in all processes, regardless of 
whether fl ammable materials are present.
Hot work includes cutting, welding, brazing, soldering 
and any process involving the application of a naked 
fl ame. Drilling and grinding should also be included 
where a fl ammable atmosphere is potentially present.
Hot work should therefore be done under the terms 
of a hot work permit, the only exception being where hot 
work is done in a designated maintenance area suitable 
for the purpose.
6.7.5 Responsibilities
The effective operation of the permit system requires 
the involvement of many people. The following specifi c 
responsibilities can be identifi ed:
(Note: all appointments, defi nitions of work requiring a 
permit etc. must be in writing. All the categories of people 
identifi ed below should receive training in the operation of 
the permit system as it affects them.)
Figure 6.9
Entering a confi ned space.
Figure 6.10
Hot work permit is usually essential except 
in designated areas.

---

Introduction to Health and Safety at Work
92
Site manager
➤
has overall responsibility for the operation and man-
agement of the permit system
➤
appoints a senior manager (normally the chief engin-
eer) to act as senior authorized person.