Introduction to Health and Safety at Work

17.7.6 Safe system of work
The detailed precautions required will depend on the 
nature of the confi ned space and the actual work being 
carried out. The main elements of a safe system of work 
which may form the basis of a ‘permit-to-work’ are:
➤
the type and extent of supervision
➤
competence and training of people doing the work
➤
communications between people inside, from inside 
to outside and to summon help
➤
testing and monitoring the atmosphere for hazard-
ous gas, fume, vapour, dust etc. and for concentra-
tion of oxygen
➤
gas purging of toxic or fl ammable substances with 
air or inert gas, such as nitrogen
➤
good ventilation, sometimes by mechanical means
➤
careful removal of residues using equipment which 
does not cause additional hazards
➤
effective isolation from gases, liquids and other 
fl owing materials by removal of pieces of pipe, 
blanked off pipes, locked off valves
➤
effective isolation from electrical and mechanical 
equipment to ensure complete isolation with lock off 
and a tag system with key security. Need to secure 
against stored energy or gravity fall of heavy presses 
etc.
➤
if it is not possible to make the confi ned space safe, 
the provision of personal and respiratory protective 
equipment
➤
supply of gas via pipes and hoses should be care-
fully controlled
➤
access and egress to give quick unobstructed and 
ready access and escape
➤
fi re prevention
➤
lighting, including emergency lighting
➤
prohibition of smoking
➤
emergencies and rescue
➤
limiting of working periods and the suitability of 
individuals.
17.7.7 Emergency arrangements – Regulation 5
Before people enter a confi ned space suitable and suffi -
cient rescue arrangements must be set up. These must:
➤
reduce the risks to rescuers so far as is reasonably 
practicable
➤
include the provision and maintenance of suitable 
resuscitation equipment designed to meet the spec-
ifi ed risks.
To be suitable and suffi cient arrangements will need to 
cover:
➤
rescue and resuscitation equipment
➤
raising the alarm, alerting rescue and watch keeping
➤
safeguarding the rescuers
➤
fi re safety precautions and procedures
➤
control of adjacent plant