Please read this before using presentation Mines Safety Roadshow 2007 - Toolbox presentation Please read this before using presentation This presentation is based on content presented at the 2007 Mines Safety Roadshow held in October 2007 It is made available for non-commercial use (eg 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: ResourcesSafety@docep.wa.gov.au or visit www.docep.wa.gov.au/ResourcesSafety

Toolbox presentation: Occupation noise in the WA mining industry Mines Safety Roadshow 2007 - Toolbox presentation Toolbox presentation: Occupation noise in the WA mining industry October 2007

Mines Safety Roadshow 2007 - Toolbox presentation Noise legislation Mines Safety and Inspection Act 1994 — Section 9 Mines Safety and Inspection Regulations 1995 — Part 7 Division 1 Approved Procedures — Regulations 7.6 and 7.10 Relevant legislation Act and regulations available from State Law Publishers at www.slp.wa.gov.au

Apply to over 300 mines operating in WA Cover more than 56,500 miners Background Apply to over 300 mines operating in WA Cover more than 56,500 miners Majority of miners work 12-hour shifts Over 74% of miners are overexposed to noise

Basic rules of working with noise 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)

Basic rules of working with noise cont. A 3 dB(A) increase corresponds to a doubling of sound energy A 10 dB(A) increase corresponds to a 10 times increase of the sound energy A 20 dB(A) increase corresponds to a 100 times increase of the sound energy

Typical noise levels at operator’s ear level Mines Safety Roadshow 2007 - Toolbox presentation Typical noise levels at operator’s ear level 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 WA data provided to Resources Safety

Standard for occupational noise For noise exposure — 85 dB(A) for 8 hours For peak noise level — 140 dB(lin)

Average noise exposure in WA mining industry Mines Safety Roadshow 2007 - Toolbox presentation Average noise exposure in WA mining industry Average noise exposure Time to reach exposure standard if not protected Surface miners 94 db(A) 1.0 hour Underground miners 101 dB(A) 12 minutes All miners 96 dB(A) 38 minutes WA data provided to Resources Safety

Employee hearing loss by occupation group Mines Safety Roadshow 2007 - Toolbox presentation Employee hearing loss by occupation group Percentage of employees with hearing loss >5% Surface mining 19.2% Metal trades 18.6% Processing plants 16.0% Underground mining 15.5% Management 14.4% Electrical trades 10.6% WA data provided to Resources Safety

Relationship between noise exposure and hearing loss Mines Safety Roadshow 2007 - Toolbox presentation Relationship between noise exposure and hearing loss Hearing loss between 5 and 9% WA data provided to Resources Safety

Mines Safety Roadshow 2007 - Toolbox presentation Employee hearing loss Average threshold shifts WA data provided to Resources Safety

Steps aiming to control noise at work Assess risks to develop a noise control plan Reduce risks for all employees Investigate and implement good practice for control of noise Prioritise noise control measures Use hearing protection for residual risks Carry out a noise dosimetry program to check the effectiveness of noise control measures

Some simple noise control techniques Application of damping material to chutes, hoppers, machine guards etc., can give a 5-25 dB reduction in the noise radiated Cabin internal noise can be reduced by 10-12 dB by applying damping pads and sound barrier mats to floor and engine bulkhead Reduce fan speed by 30% to achieve a noise reduction of 8 dB

Noise control can be complex Engage employees in process Use noise control consultants to help solve your problems if complex

Selected for protection, user preference and work activity Hearing protectors Selected for protection, user preference and work activity Guard against over-protection — isolation can lead to under-use and safety risks Require information, instruction, training, supervision and motivation Will only protect if worn all the time and properly

Rating hearing protectors The sound level conversion (SLC80 ) rating of a hearing protector, ear plugs or headset is a simple number and class rating that is derived from a test procedure as outlined in the Australian/New Zealand Standard AS/NZS 1270:2002

Class and specification of hearing protectors SLC80 Class May be used up to this noise exposure level 10 to 13 1 90 dB(A) 14 to 17 2 95 dB(A) 18 to 21 3 100 dB(A) 22 to 25 4 105 dB(A) 26 or greater 5 110 dB(A)

Mines Safety Roadshow 2007 - Toolbox presentation Ear plugs Properly fitted Wrongly fitted Ensure people are properly trained in the correct fitting of ear plugs People’s ears are different. Is there sufficient variety of ear plugs provided to suit different ear canals and different job requirements? One size (and type) may not fit all, and comfort and effectiveness are important considerations to ensure compliance.

Mines Safety Roadshow 2007 - Toolbox presentation Ear muffs Proper clamping force Worn-out head band Ear muffs left in the “up position” on hard hats may also lose their clamping force and the pads become compressed

Mines Safety Roadshow 2007 - Toolbox presentation Reduction in protection provided by hearing protectors with decreased wearing time Example: Effectiveness of wearing an ear muff with a rating of 30 dB for an exposure time of one hour Wear time Effective attenuation 60 minutes 30 dB 55 minutes 11 dB 50 minutes 8 dB 45 minutes 6 dB Sound attenuation = The reduction in the intensity or in the sound pressure level of sound which is transmitted from one point to another Effective attenuation = how well do the protectors do their job? If worn correctly for the full one hour then the attenuation (or decrease in sound energy) is 30 dB, as per the rating. But if taken off for a total of 5 minutes in that hour (e.g. to listen to someone speaking, rub ear), the effective attenuation is actually 11 dB and not 30 dB (remembering that the scale is logarithmic and 20 dB is 100 times the sound energy)!

Noise assessment as the end point Reliance on hearing protection Our challenge Away from … Noise assessment as the end point Reliance on hearing protection Towards … Control of noise risks through prioritised action plans Introducing equipment with good noise and vibration characteristics – ‘Buy Quiet’

Mines Safety Roadshow 2007 - Toolbox presentation Use this guideline as a reference on recommended ways to control noise in mines Available from Resources Safety website or contact ResourcesSafety@docep.wa.gov.au to get hardcopy

Mines Safety Roadshow 2007 - Toolbox presentation Noise posters available online or as hardcopies (contact Resources Safety)