2.0 RISK ASSESSMENT
The first step in the design process is the risk assessment.
It underpins the whole system strategy and therefore could be
argued as being the most important stage. Risk assessment is the
process of considering each part of a building from the point of
view of what fire hazards exist within an area and what would
happen in the event of fire or if explosion were to occur. This
would normally be done when considering the building from the
point of view of general safety. Clearly very small premises only
require a first level of fire protection, such as safe construction,
clear escape routes and a fire extinguisher. Equally obviously,
large hotels will require a fully automatic fire detection and alarm
system, multiple sets fire protection equipment and adequate
emergency lighting and escape signage. The Risk Assessment
process is to help building owners of buildings between these two
extremes make adequate and appropriate provision.
Building owners or operators will often want to employ the services
of a professional risk assessor to ensure that the building
is considered impartially and in adequate detail. However there
are checklists and technical advice available so that the task can
be done ‘in-house’. The Government web site for communities and
local government provides useful guidance on the subject
(
www.communities.gov.uk). It is recommended that risk assessors
should be fully familiar with the requirements of the latest edition of
BS5839:1 and if in doubt consult a suitably qualified specialist.
3.0 CONSULT WITH ALL INTERESTED PARTIES
BS5839 stresses the need to consult with all interested parties
before embarking on a detailed design. As a minimum the
following need to consult to ensure that the fire detection and
alarm system meets the requirements of all concerned.
- The authority responsible for enforcing health and safety
legislation
- The property insurer
- The building user
- The proposed installer
- Fire engineering specialists (where appropriate)
4.0 RELEVANT STANDARDS
Standards are produced for equipment and the application of
equipment, they are generally produced or endorsed by BSI.
They represent recognised best practice either for the design,
manufacture or application of a particular product or product
range.
Often these standards are called up within guidance documents
for pieces of legislation and since they represent best current
practice, can be generally be used by employers to demonstrate
that equipment they have installed is adequate and appropriate.
The following standards relate to the UK and Europe. There are
other standards that relate to specific applications (such as
hospitals or data processing installations) and other countries will
have their own standards covering the same area as those listed.
4.1 BS5839
The BS5839 suite of standards relate to specific areas of
application for fire detection and alarm equipment. Specifically
part 1 relates to public premises and part 6 relates to residential
premises.
4.1 BS5839 (cont’d)
BS5839-1 is a comprehensive code of practice for fire detection
and alarm systems, the requirements relate to both life and property
protection and the standard includes much advice and comment
with is very useful in informing the building owner or system
specifier of the background to the requirements. The standard has
been developed through input from the whole fire detection
industry over a period of 30 years and is the distillation of expert
opinion and practical advice. The application notes that follow
relate to the requirements of BS5839:1 2002.
4.2 BS5588
The parts of BS5588 form the technical element of the building
regulations for England and Wales, they should be consulted to
establish the detailed requirements for the building in question.
BS5588 is mainly concerned with the structure and design of the
building but also contains some requirements for fire detection and
alarm systems. The requirements of BS5588 are incorporated
within the building regulations giving it mandatory legal status.
4.3 BS7273, BS EN 60079-14, BS EN 50281-1-2
The parts of BS7273 are codes of practice for different types of
fire protection systems. Generally this is considered separately to
fire alarm systems but there may be occasions where a trade off
can be made between the two systems, or where the two systems
interact and must be interfaced.
BS EN 60079-14 and 50281-1-2 cover areas where there may
be risk of explosive gas/vapour or dust respectively, reference to
them may be required in certain buildings or where there is a
change of use.
4.4 EN54
The EN54 suite of standards relates to the design and
performance of items of equipment that make up a fire detection
and alarm system. Each part relates to a different piece of
equipment, for example part 3 relates to alarm devices, part 11 to
call points, part 4 to power supplies etc.
Some parts of the standards have options with requirements. These
relate to specific features that are required in certain applications
but not all. For example all control and indicating equipment must
be able to detect fire (with the help of appropriate input devices),
must monitor certain functions (such as cables for open and short
circuit faults) and must have a disablement facility so that functions
or areas of cover can be switched off for maintenance or similar
activities. However it is optional to have a test facility or delays to
outputs, but if such features are either provided or required in the
application (e.g. to allow a local search for fire prior to calling the
brigade) then those facilities must meet specified criteria.
It is therefore necessary when specifying compliance to EN54 that
the relevant part is identified and that the application standard
(such as BS5839-1) is consulted to identify specific options. For
example, the UK fire brigade almost always will require zonal light
emitting indicators to be incorporated in control equipment to show
the extent of the fire event at a glance; this is an option in EN54-2
and many countries in Europe do not require such displays.
4.5 BS7671
BS7671 was previously known as the IEE wiring regulations.
The standard is called up in BS5839-1 and covers the installation
of the system.
