1. Workplace Noise Assessment
January 2005
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2. Do We Need a Survey?
Can you understand normal speech at 2 m? (1 m for old regs)
Has your noise survey meter indicated noise levels are above the first action level?
Does your company have a policy of regular noise surveys?
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3. Who Should Carry Out the Survey?
A competent person
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4. What is a Competent Person
The person should have the following knowledge and experience
Purpose of assessment
Understanding of what information to be obtained
Appreciation of their own limitations
How to take measurements
How to record, analyse and explain the results
Care of noise measurement equipment
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5. Where Do You Start? Tour of the factory
Make notes about noisy machines
Ask workers about their work patterns
Are there any machines that are not working
Determine shift patterns
Assess the risk
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6. Choice of Noise Equipment
Do we need an integrating SLM?
Do we need to carry out octave band analysis?
Will “C” weighting be required
Do we need to measure “peak”?
Do we need dose meters?
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7. Calibration
All noise measuring instrumentation must be calibrated before measurements take place
Equipment should be calibrated after use
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8. The Survey Where to measure Close to operators ear
Not too close to affect measurements
Should a tripod be used?
SLM should be held at arms length
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9. The Survey How long? How long should measurements be?
Long enough to be representative
Measure a complete cycle of machine
Do I need to use a dose meter?
Are there workers that are transient?
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10. The Survey Observations How is the noise generated
Does the noise have peculiar characteristics
Could screening be used to reduce noise
Could machines be moved
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11. The Report Introduction Methodology Results Discussion Recommendations
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12. Introduction Sets the scene Details of where the survey was made
The shift patterns
Who carried out the survey
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13. Methodology State the methods used The equipment used in survey
Serial number of instruments
Calibration
Methods used
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14. Results Results & Calculations All the raw data from the survey
Calculations of LEP,d’s
Factual data about machines
Calculation for hearing protection
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15. Discussions Talks about the survey in depth
Contain factual information on survey
Point out areas where action levels are exceeded
State areas where signs are to be erected
How to silence noisy machines
Ear protectors
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16. Recommendations Review the items contained in discussion
Final recommendation on how to control noise
Recommend ear protection to be provided
Training to be given
When survey should be repeated
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17. Case Studies
Noise at Work
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18. Case 1 Manufacturer of electrical switchgear
Various metal work processes
About 200 employees
Peak levels of 140 dB exceeded
due to poor handling of metal sheet
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19. Case 1 Hand held sound level meter measurements Personal dose meters
LAeq
Octave bands
Personal dose meters
12 members of staff
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20. Case 1 Less than 80 dB(A) Bending machine
Deburring machine with silencer
Press
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21. Case 1 80 to 85 dB(A) Assembly area Hole punch Shot blaster
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22. Case 1 85 to 90 dB(A) Laser cutter Hand deburring
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23. Case 1 90 + dB(A) Circular saw Cross cut saw Pneumatic riveting
Circular sander
Frame riveting
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24. Case 1 Material handling 2 saws - very high noise levels
staff training
2 saws - very high noise levels
Hearing protection zone (even though intermittent use)
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25. Case 1 Laser cutter Belt sander for deburring
inherently quiet but noise from material handling - shaking out
Belt sander for deburring
Hearing protection zone
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26. Case 1 Shot blaster Hand deburring machine fit attenuator to exhaust
86.5 dB(A) in use dB(A) with manufacturer’s silencer
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27. Case 1 Factory ventilation fans remove individual controls
reduce maximum speed
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28. Case 1
Ear plugs were already widely used and proved suitable for all situations
Recommended workers in dirty areas should use ear defenders
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29. Case 2 Significant variation of noise levels Workforce static
Approx. 85 employees in the workforce
7 measurement sessions
6 dose meters
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30. Case 2 Result summary for worst affected LEP,d Lpeak 1 90 130 2 85 130
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31. Think Environment Think Casella

32. Case 2 Result summary for worst affected LEP,d Lpeak Trumpet 90 130
Viola
Cello
Percussion
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33. Think Environment Think Casella

34. Case 2 Small curved clear plastic screens Ear plugs
Dose reduced by 1-3 dB(A)
Lpeak reduced by 4-5 dB
Ear plugs
with flat attenuation properties
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