b63b6b8af1940be8e06dea3965245fb9.ppt
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Please read this before using presentation l l 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 Power. Point 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: Resources. Safety@docep. wa. gov. au or visit www. docep. wa. gov. au/Resources. Safety Department of Consumer and Employment Protection Resources Safety 1
Toolbox presentation: Occupation noise in the WA mining industry October 2007
Noise legislation l l l 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 3
Background l l 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 4
Basic rules of working with noise l l l The noise levels are described in decibels (d. B) They can not be added or subtracted in the usual arithmetic way because the d. B scale is logarithmic Two identical tools emitting noise of 90 d. B(A) produce the combined noise level of 93 d. B(A), not 180 d. B(A) Department of Consumer and Employment Protection Resources Safety 5
Basic rules of working with noise l l l cont. A 3 d. B(A) increase corresponds to a doubling of sound energy A 10 d. B(A) increase corresponds to a 10 times increase of the sound energy A 20 d. B(A) increase corresponds to a 100 times increase of the sound energy Department of Consumer and Employment Protection Resources Safety 6
Typical noise levels at operator’s ear level Noise source Haulage truck 80 -89 Dozer 82 -85 Excavator 81 -86 Jumbo drill 102 -108 Impact wrench 97 -103 Angle grinder 92 -106 Airleg drill Department of Consumer and Employment Protection Noise range d. B(A) 110 -120 Resources Safety 7
Standard for occupational noise l For noise exposure — 85 d. B(A) for 8 hours l For peak noise level — 140 d. B(lin) Department of Consumer and Employment Protection Resources Safety 8
Average noise exposure in WA mining industry Average noise exposure Surface miners Underground miners All miners Department of Consumer and Employment Protection Time to reach exposure standard if not protected 94 db(A) 1. 0 hour 101 d. B(A) 12 minutes 96 d. B(A) 38 minutes Resources Safety 9
Employee hearing loss by occupation group Percentage of employees with hearing loss >5% l Surface mining l Metal trades 18. 6% l Processing plants l Underground mining l Management 14. 4% l Electrical trades Department of Consumer and Employment Protection 19. 2% 16. 0% 15. 5% 10. 6% Resources Safety 10
Relationship between noise exposure and hearing loss Hearing loss between 5 and 9% Department of Consumer and Employment Protection Resources Safety 11
Employee hearing loss Average threshold shifts Department of Consumer and Employment Protection Resources Safety 12
Steps aiming to control noise at work l Assess risks to develop a noise control plan l Reduce risks for all employees l Investigate and implement good practice for control of noise l Prioritise noise control measures l Use hearing protection for residual risks l Carry out a noise dosimetry program to check the effectiveness of noise control measures Department of Consumer and Employment Protection Resources Safety 13
Some simple noise control techniques l l l Application of damping material to chutes, hoppers, machine guards etc. , can give a 5 -25 d. B reduction in the noise radiated Cabin internal noise can be reduced by 10 -12 d. B 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 d. B Department of Consumer and Employment Protection Resources Safety 14
Noise control can be complex Engage employees in process Use noise control consultants to help solve your problems if complex Department of Consumer and Employment Protection Resources Safety 15
Hearing protectors l l 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 16
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 17
Class and specification of hearing protectors Class May be used up to this noise exposure level 10 to 13 1 90 d. B(A) 14 to 17 2 95 d. B(A) 18 to 21 3 100 d. B(A) 22 to 25 4 105 d. B(A) 26 or greater 5 110 d. B(A) SLC 80 Department of Consumer and Employment Protection Resources Safety 18
Ear plugs Properly fitted Department of Consumer and Employment Protection Wrongly fitted Resources Safety 19
Ear muffs Proper clamping force Department of Consumer and Employment Protection Worn-out head band Resources Safety 20
Reduction in protection provided by hearing protectors with decreased wearing time Example: Effectiveness of wearing an ear muff with a rating of 30 d. B for an exposure time of one hour Effective attenuation 60 minutes 30 d. B 55 minutes 11 d. B 50 minutes 8 d. B 45 minutes Department of Consumer and Employment Protection Wear time 6 d. B Resources Safety 21
Our challenge Away from … l Noise assessment as the end point l Reliance on hearing protection Towards … l l 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 22
Use this guideline as a reference on recommended ways to control noise in mines Department of Consumer and Employment Protection Resources Safety 23
Noise posters available online or as hardcopies (contact Resources Safety) Department of Consumer and Employment Protection Resources Safety 24
b63b6b8af1940be8e06dea3965245fb9.ppt