Transcript Mines Safety Roadshow 2008 - Department of Mines and Petroleum

Please read this before using presentation

This presentation is based on content presented at the Mines Safety
Roadshow held in October 2008 and Exploration Safety Roadshow
held in November 2008

It is made available for non-commercial use (e.g. toolbox meetings)
subject to the condition that the PowerPoint file is not altered without
permission from Resources Safety

Supporting resources, such as brochures and posters, are available
from Resources Safety

For resources, information or clarification, please contact:
[email protected]
or visit
www.docep.wa.gov.au/ResourcesSafety
Department of Consumer
and Employment Protection
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Toolbox presentation: How can we stop noise
damaging hearing
Outline
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Why is protecting our hearing important?
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Terminology and setting the scene
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Signs of NIHL
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How much noise?
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Managing noise
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PPE
NIHL = noise-induced hearing loss
Department of Consumer
and Employment Protection
Resources Safety
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What is the impact of NIHL?
Recognising NIHL
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Everyone appears to be mumbling
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Can’t hear conversations at home or work
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May misinterpret what many people say
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Have to ask people to repeat what they said – then they yell
Consequences
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Hearing loss is insidious and irreversible
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Affects quality of life and is extremely isolating
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Increased opportunity for miscommunication (potential for poor
outcomes)
Department of Consumer
and Employment Protection
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Basic rules of working with noise
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The noise levels are described in decibels (dB)
They can not be added or subtracted in the
usual arithmetic way because the dB scale is
logarithmic
Two identical tools emitting noise of 90 dB(A)
produce the combined noise level of 93 dB(A),
not 180 dB(A)
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and Employment Protection
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Basic rules of working with noise (continued)
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3 dB(A) increase corresponds to a doubling of
sound energy
10 dB(A) increase corresponds to a 10 times
increase of the sound energy
20 dB(A) increase corresponds to a 100 times
increase of the sound energy
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and Employment Protection
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Typical noise levels of common sounds
Noise source
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and Employment Protection
dB(A)
30 m from jet aircraft
140
Chainsaw
110
Kerbside of busy road
80
Conversational speech
60
Quiet bedroom at night
30
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Standard for occupational noise
Noise exposure — 85 dB(A) for 8 hours
Peak noise level — 140 dB(lin)
If you can’t hear speech one metre from source
then background noise is too loud – exceeds 85
dB(A)
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and Employment Protection
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Typical noise levels at operator’s ear level
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and Employment Protection
Noise source
Noise range
dB(A)
Haulage truck
80-89
Dozer
82-85
Excavator
81-86
Jumbo drill
102-108
Impact wrench
97-103
Angle grinder
92-106
Airleg drill
110-120
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Average noise exposure in WA mining industry
Surface miners
Underground
miners
All miners
Department of Consumer
and Employment Protection
Average noise
exposure
Time to reach
exposure standard
if not protected
94 db(A)
1.0 hour
101 dB(A)
12 minutes
96 dB(A)
38 minutes
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Incidence of hearing loss
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NIOSH (USA) reports that 49% of male, metal/non-metal
miners will have a hearing impairment by age 50 (versus 9%
for general population), rising to 70% by age 60
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About 50% of WA mining employees between 40 and 50
years old have a significant threshold hearing shift –
increases to 82% for those aged 50 and above
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Significant hearing threshold shifts > 20 dB(A) across both
ears at 3,4 and 6 kHz
Department of Consumer
and Employment Protection
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Examples of potential noise hazards
Mining
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Jumbo drilling
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Angle grinding
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Ball mills
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Mobile plant
Exploration
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High pressure air-booster
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RC drilling causes greater high impact noise
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Diamond drilling - high frequencies
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and Employment Protection
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Some risk factors
Duration and frequency of exposure
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Tasks involving repetitive or sustained exposure to noise
Peak noise
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Tasks with sudden loud noise (acoustic shock)
Communication requirements
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Tasks that require communication between or to and from
workers in noisy places
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and Employment Protection
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Addressing risk factors
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Employer’s responsibility to reduce noise as much as
possible (ALARP) – assess workplace noise, develop and
implement noise control plan
Employee’s responsibility to comply with noise
management procedures
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Control measures developed by consultative process
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Role of safety and health representatives
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Risk management approach
Hierarchy of controls
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Elimination
Substitution
Isolation
Engineering
Administrative
PPE
Ultimate aim of risk management is elimination of hazards,
and PPE is used as a last resort
More than one measure may be used to reduce exposure to
hazard
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and Employment Protection
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Noise hazards – focus on the controls
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Undertake noise surveys of all equipment under usual
operating conditions
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Noise footprint of equipment – show which parts should be
avoided on a laminated A4 sheet
Implement engineer controls prior to commissioning
equipment
Appropriate PPE can be supplied based on noise survey
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Consulting employees on their preferences on fit and comfort
will improve their effectiveness as they will be used properly
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and Employment Protection
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Risk management approach
(continued)
Design options – do it right from the start
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‘Buy Quiet’ programs – look for good noise and vibration
characteristics
Workshop layout
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Doubling distance from noise will halve noise level received by
ear
Avoid work areas in corners with reflective surfaces
Substitution, isolation and engineering options
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Use damping materials and sound barriers
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Change activity (e.g. reduce fan speed)
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and Employment Protection
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Noise control – design
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Noise control – design
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and Employment Protection
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PPE – hearing protection considerations
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Chosen for task – beware under- and over-protection issues
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Fit tested
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Provide information and instruction
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Maintained – and replaced as necessary
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Worn before entering noisy area – and left on
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Used correctly
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Address communication issues – workers should not be
removing protection in noisy areas to talk to each other or
speak on radios or phones
Department of Consumer
and Employment Protection
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Reduction in protection with decreased
wearing time
Effectiveness of wearing an
ear muff with a rating of 30
dB for an exposure time of
one hour
If earmuff removed or lifted
to speak to fellow worker for
total of 5 minutes in the one
hour period, effective
attenuation is 11 dB!
Department of Consumer
and Employment Protection
Wear time
Effective
attenuation
60 minutes
30 dB
55 minutes
11 dB
50 minutes
8 dB
45 minutes
6 dB
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