SILICA: How WEL are
you managing the risk?
Dust is generated in many quarry processes,
particular
respirable
minimised by maintaining road surfaces and
Inspectors will be using COSHH essentials in
from overburden stripping through extraction of
crystalline silica (RCS) carry a greater risk of
sufficiently regular trips by water bowser), as
assessing compliance. If, on a quarry visit, they
the target mineral resource, through processing
ill health, due to the nature of their reaction
well as suitably designed and maintained
believe exposure to RCS has not been prevented,
and loading the end product. Silica is a
with the body. These more harmful dusts have
plant and equipment to contain dusty
or where prevention was not reasonably
naturally occurring mineral, which is very
their own WELs. Since 2002 the WEL for RCS
has been 0.3 mg/m 3 .
processes and remove dust from enclosed
practicable it was not being ‘adequately
work areas. The use of personal protective
controlled’, they will consider enforcement
common on the earth’s surface and occurs in its
dusts,
including
crystalline form in many different rock types.
equipment is a last resort – do not rely on
If RCS enters the lungs, it causes a particular
this as the sole means of protecting workers
recognisable disease known as silicosis. Scar
from dust exposure.
tissue develops which impairs lung function and
leads to chronic bronchitis and shortness of
To coincide with the new WEL later this year,
breath. Silicosis normally develops over a long
HSE
period and often only becomes apparent after
information sheets, an addition to the
retirement; however with intense daily exposure
existing series of COSHH Essentials guidance
to RCS it can develop much more quickly.
( w w w. c o s h h - e s s e n t i a l s . o r g . u k ) . T h e s e h a v e
is
publishing
a
series
of
silica
been developed in consultation with industry
Recent research has revealed that there is
to provide practical guidance on workplace
significant risk of developing silicosis even
control measures for certain processes. HSE’s
where RCS is controlled at the WEL. For this
guidance is similar to that being produced by
reason HSC is considering a recommendation
Eurosil, which represents at European level
f r o m t h e A d v i s o r y C o m m i t t e e o n To x i c
the industries with an interest in processes
Substances (ACTS) that the WEL be reduced
to 0.1 mg/m 3 . This change is likely to take
and products containing silica. British quarry
action. ‘Adequate control’ for RCS means
Dust spillage should
operators can implement either set of
applying the principles of good practice for the
be contained and
effect in the autumn. If exposures to RCS are
guidance to help them comply with COSHH.
control of exposure to RCS, eg implementing
vacuumed, not swept
the guidance in COSHH essentials, and ensuring
with a broom
controlled to below 0.1 mg/m3 there should
be a very low risk of developing silicosis.
Once exposure is 0.1 mg/m 3 or greater, the
A
risk increases significantly.
Dialogue
further
important
development
at
that the WEL is not exceeded.
European level is the European Social
Agreement
on
silica,
which
The
Q N J A C ’s
guidance
on
Occupa-
representatives of the British quarry industry
tional health management in the quarry
Lung X-ray showing
Breathing in dust of any sort is potentially
Silicosis is a completely preventable disease
have been very significantly involved with.
industry,
scarring caused by
harmful, and exposure to dust in the
if control measures are properly designed,
By signing up to the agreement, organisations
( w w w. h s e . g o v. u k / a b o u t u s / m e e t i n g s / q n j a c /
exposure to RCS
workplace must be controlled under the
implemented and maintained. To control risk
commit to standards of control, recording
qnjac-ohg.pdf) is likely to be revised soon to
requirements of the Control of Substances
from RCS, employers must apply the
and reporting. Actions detailed in the
reflect changes to good industry practice in
Hazardous to Health Regulations 2002
principles of COSHH.*
European Social Dialogue Agreement address
controlling exposure to silica and other
employers’ duties.
health risks in quarrying.
(COSHH).
Under
COSHH
there
is
a
published
in
2004,
Wo r k p l a c e E x p o s u r e L i m i t o r W E L f o r
inhalable general dust of 10 mg/m3, or
In a quarry environment where silica is a
constituent of the rock, practical control of
* Further information is available in HSE’s free leaflet, COSHH a brief guide to the Regulations: What
4 mg/m 3 for the finest or respirable dust, ie
RCS exposure will depend on establishing and
you need to know about the Control of Substances Hazardous to Health Regulations 2002 (COSHH)
that which is in such small particles it can be
maintaining management systems (eg to
Leaflet INDG136(rev3) HSE Books 2005 (single copy free or priced packs of 10 ISBN 0 7176 2982 1)
b r e a t h e d d e e p i n t o t h e l u n g s . H o w e v e r,
ensure dust from vehicle movements is
Web version: www.hse.gov.uk/pubns/indg136.pdf.