Transcript Noise at Work

Noise at Work
Awareness of Noise and Hearing
Protection in the
University of Sheffield
Scope of the Problem
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In the UK there are
over 170,000 people
with significant
work-related hearing
damage
14,200 are serious
enough affected to
receive disablement
benefit
Noise is an ancient problem!
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Roman poets
complained about
the racket of iron
cart-wheels on the
cobbles
What is noise?
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Unpleasant or unwanted
sound
When unwanted noise
gets loud enough
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It is unpleasant
It is distracting
It is tiring & stressful
Higher levels cause
permanent hearing damage
Likelihood of Damage
Depends mainly on:
 Volume (loudness)
 Frequency (pitch)
 Exposure time
Can be work exposure,
social exposure or
both
Damage can include:
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Temporary hearing
loss
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hearing returns after
a short period away
from noise
Permanent hearing
loss
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Permanent damage or
destruction of hair
cells in the ears.
Hearing cannot be
restored
Signs of developing hearing loss
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Inability to hear soft
or high pitched
sounds
Trouble
understanding
conversation at a
distance or in a
crowd
Ringing in the ears
Others can hear
something you can’t
There is no cure for hearing damage!
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Normal hearing can
never be restored
Hearing aids do not
restore noisedamaged hearing
At best, they help
the person a little
Frequency of Sound
Infra-
Normal
Ultra-
Sound
Sound
Sound
Noise Levels
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Ear is most sensitive
to normal frequency
sound
The dBA scale takes
this into account
when measuring
noise levels
Measurement of Noise
Loudness is measured in decibels
170 dB
Jet airliner
120 dB
Riveting hammer
110 dB
Shouting loudly
70 dB
Street sounds
38 dB
Quiet bedroom
This is a logarithmic scale – an increase of
1dB means about 30% more noise
What Law applies?
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The Control of Noise
at Work Regulations
2005 (Commencement
date April 2006 except for
music industry)
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The Health & Safety
at Work etc Act
1974
Risk Assessment
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Observe procedures
Refer to standard
data
If necessary,
measure noise levels
Compare with action
levels
Identify control
measures
Action and Limit Values
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Lower action value (LAV)
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Upper action value (UAV)
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80dBA – 8hrs Peak – 135dBA
85dBA – 8hrs Peak – 137dBA
Exposure limit value (ELV)
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87dBA – 8hrs Peak – 140dBA
Can take account of hearing protection
If your average daily exposure is
over 80dB(A)
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The employer must:
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Inform you of the
risks to your
hearing from noise
and how you can
reduce those risks
Make hearing
protective
equipment available
If your average daily exposure is
over 85dB(A)
Your employer must:
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Try to reduce noise at source
Provide hearing protection &
insist on its use
Identify & sign ear protection
zones
Conduct noise assessments &
keep records of them
Provide hearing checks if
requested
If your average daily exposure is
over 87dB(A)
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This is a
maximum & must
not be exceeded
Noise to the ear
must be reduced
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Preferably at
source
Otherwise by
hearing protection
Control of Noise
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Preferably eliminate or
reduce it at source eg
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Maintenance &
lubrication
Anti-vibration mounting
Sound absorbing
materials
Enclosure
Reducing exposure time
Hearing protection
Ear Plugs
 Must be kept clean (many
are single use)
 Must be put in properly
(there is a special
technique)
 Generally comfortable to
wear especially in hot
weather
Hearing protection
Canal Caps
 Like in-ear ear plugs on a headband
 Pleasant to wear
 Often do not completely seal in the ear
 Generally not a good idea for >85dB
for prolonged periods
Hearing protection
Ear Muffs
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Must fit snugly – one size fits
most people
Generally very effective if
worn properly – beware of
glasses
Tend to be uncomfortable in
hot weather
Special types available eg. for
wearing safety helmets, for
workers near high voltage
Can be shared but cleaning
routine required
Hearing protection
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The effectiveness of hearing
protection varies according
to type, manufacture and
correct wearing.
Most will reduce noise at the
ear by about 15 - 20dBA
Don’t over-protect or
warnings may not be audible
Hearing protection
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Ensure it is suitable for
the job
Regular maintenance &
record keeping
required
Home-made protectors
don’t work (eg cotton
wool)
Wear it when you are
supposed to – you
MUST BY LAW
Hearing protection
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Try to limit your
time in noisy
areas
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Remember the
effect is
cumulative
Hearing protection
Protect your
hearing in a social
context too eg:
 Loud music
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Personal stereos
Car entertainment
DIY & garden
tools
Don’t take noise for granted!
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Hearing damage
creeps up on you
Once it has
happened, there
is no cure
Further Advice?
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Contact Safety Services
The Health & Safety Executive have a
useful leaflet which can be found:
http://www.hse.gov.uk/pubns/indg362.
pdf