Legal
A breath of fresh air
Installing local exhaust ventilation systems in buildings is crucial
in order to remove harmful contaminants and protect workers’
health, as Hywel Davies explains
E
very year, more than 4,000 workers in Britain It is also vital to provide the means to see if the

contract occupational diseases, including system is not working properly. Installers must put
cancer and serious lung conditions. These are in an LEV system and commission it thoroughly, to
caused by breathing dust, fumes or vapours at ensure that it does adequately control contaminant
work. Most of these illnesses are entirely avoidable exposure. The only way to check this is by physical
with proper local exhaust ventilation systems to testing to demonstrate that the system controls
remove airborne contaminants before people breathe exposure effectively.
them in. They should also provide a full commissioning
Under the Health and Safety at Work Act, all report (which goes into the log book). Employees need
employers have an absolute legal duty to safeguard their training to use the system,
workers. In addition, as part of its disease-reduction including confirming
programme, the Health and Safety Executive (HSE) for themselves that it is
considers occupational disease to be an enforcement working effectively.
Under the Health
priority, and so plans to raise the profile of local exhaust The clear message
and Safety at
ventilation and to increase its enforcement activity in coming across from
this area for the foreseeable future. HSE is that this issue
Work Act, all employers
HSE recently ran pilot workshops to tell employers is important for worker
have an absolute legal duty
in the Midlands about their duties, and to bring health, and that it will
the supply side in to explain what is available and be of growing concern
to safeguard
how employers can meet their legal duties to the to HSE inspectors. This
their workers
employees in their care. provides opportunities
Local exhaust ventilation (LEV) equipment provides for ventilation engineers
protection in that it is designed to enclose a process who have the competence to design LEV systems, as
which generates hazardous airborne particles, or there is likely to be growing interest from employers.
to capture the hazardous material and draw it away CIBSE has been recognised by the HSE as having
from the breathing zone. The Act requires that these many members with appropriate knowledge in this
systems be examined annually. Failure to do so can field.
incur prosecution. At present, the HSE estimates that For those who want to demonstrate specific
there are 140,000 of these installations operating, of competence in this area, this can currently be done
which only half are properly inspected. through the Basic design principles of local exhaust
Where LEV is needed, it requires careful design to ventilation systems qualification, which is offered by
ensure adequate flow rates, correctly directed to draw the British Occupational Health Society (BOHS).
the contamination into the extract system. The effect There is also a need for competent testers. The
of draughts on the performance of the extraction current recognised qualification for this is the BOHS
system also needs to be considered. Initial Appraisal and Thorough Examination and
For more information about
LEV, visit www.hse.gov.uk/
It is important for the designer to establish what Testing of Local Exhaust Ventilation Systems.
lev. The site provides further
the employer – their client – needs, and to design CIBSE members are well-placed to engage with
HSE guidance for designers,
the system accordingly using the correct hoods or the drive to raise standards of occupational heath by installers and examiners of
enclosures to control the processes and sources. delivering LEV systems that are fit for purpose and
LEV, as well as employers and
They should also provide a user manual and log book help to prevent the many blighted lives that result
their employees who depend
on LEV to protect their health.
for the system, which sets out how the system works, from avoidable occupational disease. l
It also provides links to HSE
and how it should be maintained, in terminology that
publications and to other
the employer and users can readily understand.
Hywel Davies is technical director of CIBSE
useful information sources.
20 CIBSE Journal April 2009 www.cibsejournal.com
CIBSEapr09 pp20 legal.indd 22 2/4/09 14:57:26
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