INDG380 TREAD SAFELY - HSE

health hazards
16
Tread safely health hazards
Section 10 Noise
Some activities in the retread industry like shot
blasting, tyre buffing, skiving and inflation testing
can produce high noise levels. If employees are
exposed to high noise levels for prolonged periods
of time there is a serious risk of them suffering
irreversible hearing loss. Occupational hearing loss
is a serious, disabling condition and successful civil
claims against employers for failing to prevent noiseinduced
deafness are common. They often lead to
settlements that prove expensive for the employer.
First action level
Where employees are exposed to a daily personal
noise exposure of 85 decibels (dB(A)) or more you
need to take action. This is known as the first
action level. As a rough guide, 85 dB(A) is about
the noise level you would experience in a busy city
street full of heavy traffic. At this level you have to
raise your voice to make yourself heard by
someone standing 2 m away.
Second action level
A daily personal noise exposure of 90 dB(A) is
known as the second action level. At 90 dB(A) you
would have to raise your voice to make yourself
heard by someone standing 1 m away. Where any
employees are exposed to the second action level,
or above, there are additional measures that you
must take.
Here are some typical noise levels to which
operators can be exposed in retread processes.
Skiving 94 to above 100 dB(A)
Buffing 85 to 92 dB(A)
Inflation testing Over 90 dB(A)
Shot blasting Over 100 to 110 dB(A)
Note: Every time the noise level increases by
3 dB(A) the noise energy approximately doubles.
Therefore 93 dB(A) is approximately twice 90 dB(A).
What do I have to do?
If any employees are likely to have a daily personal
exposure at, or above, the first action level you must
ensure that a competent person carries out
a noise assessment to identify employees who are at
risk and to provide the information to help you decide
what noise-control measures you need to take. You
can get the names of organisations that are able to
help you carry out this assessment from RMA, BRMA
or the British Institute of Occupational Hygiene (BIOH)
(Tel: 01332 298087, website: www.bioh.org).
You must reduce the risk of hearing damage to
be as low as reasonably practicable by reducing the
level of noise generated in the first place. This may be
achieved by using quieter machinery and equipment
wherever possible, or by providing acoustic
enclosures around noisy equipment and segregating
activities that generate high noise levels from other
areas to avoid unnecessary noise sharing.
If, after you have done all this, there are still
some employees who are exposed to noise levels
at, or above, the first action level but below the
second action level you must inform them of the
noise levels to which they are exposed, explain the
risks and make suitable hearing protectors available
for them to wear if they wish.
If there are some employees who are exposed
to the second action level or above, you must issue
suitable hearing protection and require it to be worn
correctly. You will need to train employees in the
correct use and maintenance of hearing protectors.
At or above the second action level you must
designate and clearly mark ear protection zones
within the workplace and you must enforce the
proper wearing of hearing protectors by anyone
entering those zones. This includes supervisors,
managers, office staff and visitors who need to
enter the zones even if only for a short period of
time. Managers and supervisors should set a good
example by wearing their hearing protectors in the
ear protection zones to persuade other employees
to do the same.
Tyre-buffing machine example
As an example, these are the measures you should
consider at a noisy tyre-buffing machine where
noise levels between 85 and 92 dB(A) can be
expected at the buffing operator’s position unless
suitable control measures are put in place. The
measures should be applied in this order of
preference with personal hearing protection being
relied on only as a last resort.
Step 1 - Reduce noise at source
For example, use peeling to remove the bulk of the
tread to minimise the amount of noisy buffing
required. Fit noisy air exhausts and extraction
systems with suitable silencing devices.
Step 2 - Provide acoustic enclosures
Automatic buffing machines can be placed inside
acoustic enclosures. These can significantly reduce
the noise levels at the operator’s working position.