Department of Consumer and Employment Protection Resources Safety 1 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: or visit

Toolbox presentation: Occupation noise in the WA mining industry October 2007

Department of Consumer and Employment Protection Resources Safety 3 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

Department of Consumer and Employment Protection Resources Safety 4 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

Department of Consumer and Employment Protection Resources Safety 5 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)

Department of Consumer and Employment Protection Resources Safety 6 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

Department of Consumer and Employment Protection Resources Safety 7 Typical noise levels at operator’s ear level Noise source Noise range dB(A) Haulage truck80-89 Dozer82-85 Excavator81-86 Jumbo drill Impact wrench Angle grinder Airleg drill

Department of Consumer and Employment Protection Resources Safety 8 Standard for occupational noise For noise exposure — 85 dB(A) for 8 hours For peak noise level — 140 dB(lin)

Department of Consumer and Employment Protection Resources Safety 9 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

Department of Consumer and Employment Protection Resources Safety 10 Employee hearing loss by occupation group Percentage of employees with hearing loss >5% Surface mining19.2% Metal trades18.6% Processing plants16.0% Underground mining15.5% Management14.4% Electrical trades10.6%

Department of Consumer and Employment Protection Resources Safety 11 Relationship between noise exposure and hearing loss Hearing loss between 5 and 9%

Department of Consumer and Employment Protection Resources Safety 12 Employee hearing loss Average threshold shifts

Department of Consumer and Employment Protection Resources Safety 13 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

Department of Consumer and Employment Protection Resources Safety 14 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 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

Department of Consumer and Employment Protection Resources Safety 15 Noise control can be complex Use noise control consultants to help solve your problems if complex Engage employees in process

Department of Consumer and Employment Protection Resources Safety 16 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

Department of Consumer and Employment Protection Resources Safety 17 Rating hearing protectors The sound level conversion (SLC 80 ) 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

Department of Consumer and Employment Protection Resources Safety 18 Class and specification of hearing protectors SLC 80 Class May be used up to this noise exposure level 10 to dB(A) 14 to dB(A) 18 to dB(A) 22 to dB(A) 26 or greater5110 dB(A)

Department of Consumer and Employment Protection Resources Safety 19 Ear plugs Properly fittedWrongly fitted

Department of Consumer and Employment Protection Resources Safety 20 Ear muffs Proper clamping forceWorn-out head band

Department of Consumer and Employment Protection Resources Safety 21 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 minutes30 dB 55 minutes11 dB 50 minutes8 dB 45 minutes6 dB

Department of Consumer and Employment Protection Resources Safety 22 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’

Department of Consumer and Employment Protection Resources Safety 23 Use this guideline as a reference on recommended ways to control noise in mines

Department of Consumer and Employment Protection Resources Safety 24 Noise posters available online or as hardcopies (contact Resources Safety)