4. The basics
L= Level, A,C,Z= Weighting F,S,I = Speed The measurement
L A F MX
LAF MX LC pk
LAF MN LA eq (Leq)
L ep’d
5. What is LAeq
LAeq is the amount of noise we would be exposed to if we stayed in the same
area for 8 hours
It is not our actual exposure
However
We need LAeq to calculate our exposure.
Some noise meters do not give LAeq and
therefore should not be used. When
measuring we use the meter to give us
a Steady Measurement or if that’s not possible
we measure one complete cycle
7. = 86 + 92
We take the difference
between the two (6)
using the table look at
the amount to be
added (1) and add it to
the higher
So
86 + 92 = 93 dBA
Working out Lep’d
8. LCpk
Peak noise is the highest point measured and also has
legislation as to its level.
10. Employer must:
• Reduce risks to
lowest practicable
level
• Keep records and
make them available
including audiometry
(if done)
• Buy quiet
Below lower action
11. • 80dB(A) LEP,d
• LCPK= 135dB
• Take action as in
regulations
Lower exposure action
12. Above lower action
Employer must:
• Identify all employees at risk
• Put up signs
• Review if any changes to noise levels
• Repeat assessment <2 years
• Inform employees of risk
• Provide choice of PPE on request (first aid)
• Provide training / education
• Noise Control
13. • 85dB LEP,d
• LCPK= 137dB
• Take action as in
regulations
Upper exposure action
14. Abover upper action
Employer must:
• Demarcate as Noise Hazard Zones
• PPE must be used at all times
• Noise control to reduce exposure
• If Lepd is over 95dBA then must use octave band
method to check if hearing protection is effective
Note: For peak action level, take the same action as
for second action level
15. Exposure limit value
• 87dB(A) LEP,d exposure limit
• 140dB LCPK exposure limit (200 Pascals)
• Is the maximum permissible estimated operator noise dose
whilst wearing (and not wearing) hearing protection
• Value at the ear after taking into account any PPE
• Therefore necessary to calculate effectiveness of PPE
• NOT a target, but minimum acceptable
• Target these individuals first
16. Risk assessment
• Assess risks to Health and Safety
• Done to identify actions to reduce risks
• Necessary when lower action levels likely to
be exceeded
• Should assess exposure, measure if likely to
be above second action levels
17. Employees over the
second action level
have the right to a
hearing check
(audiometric test)
As a preventative
measure individuals
who may be
susceptible to noise
below this level should
also be tested e.g.
those with previous
damage.
Audiometry
18. The ‘competent person’
• Competent person does not appear in regs
• Risk assessment/control measures to be
competently planned and carried out
• Rely on ‘expert intermediaries’ for advice and
services where necessary
• Guidance will be given to judge when advice
is needed
19. Two main types of
instrument are used to
perform workplace
noise assessments
• Sound Level Meter
(SLM)
• Dosimeter
S.L.M. or Dosimeter?
20. • Weighs only 68g
• Measures Personal
Exposure
• No cable
• Display & Visual
alarms
• 2 Button operation
• Automatic
calibration
dBadge
21. All instruments should
be calibrated prior to
measurement
• CEL-120
• Class 1 or 2
• Automatically
adjusts for
cavity
Calibrators
22. Taking a measurement
• What to measure?
• When to measure?
• How to measure?
• What to ask the person being measured?
• How to ask them?
• What to write down?
23. Taking a measurement
So now we should have
• Their name
• What they are doing and how they do it
• Where you measured it
• Who is working with or near them
• How long they do it for
• The LAeq and LCpk
• HML or Octave values
25. The results
• So what do we do now we have all this information,
what do we actually do with it?
• Write a report ! ! ! !
• What do we put on the report?
• Who is the report for?
• What action to take on the findings?
• Can we make it quieter and not use PPE?
27. How to measure for correct hearing protection
Octave band method
Needs frequency analyser 31.5Hz - 8KHz
• HML Method
Needs C and A weighted LEQ
• SNR Method
Needs C weighted LEQ
Octave band is the preferred method
28. PNR = M-(H-M) / 4 x (LC - LA - 2)
OR
PNR = M-(H-M) / 8 x (LC - LA - 2)
LAeq Octave’s less
octave attenuation
Lceq - SNR
36. What is it?
Hand-arm vibration syndrome (HAVS) causes
symptoms in fingers, hands and arms from vibrating
tools.
HAVS is caused by repeated and frequent use of hand-
held vibrating tools. It may also be caused by holding
or working with machinery that vibrates.
It is not clear how vibration causes the condition. It is
believed to be due to slight but repeated injury to the
small nerves and blood vessels in the fingers.
37. What is it?
At first the fingers may go white and cool. This is due to the small blood
vessels narrowing (going into spasm).
They then go a bluish colour. This is due to the oxygen being used up from
the reduced blood supply of the narrowed blood vessels.
Some people do not have the full classic colour changes
Numbness (loss of feeling) and/or tingling (pins and needles)
It may be mild and just affect the tips of the fingers Minor damage to the
muscles, joints and bones may cause aches and pains in the hands and
lower arm.
The strength of your grip may be weakened.
43. Risks
• How high the level of vibration is
• How long the equipment is used for – short
exposures and occasional spells can be
equally as damaging
• How tightly the equipment is gripped
• How awkward the equipment is to use
• How cold and wet it is when the equipment is
used.
44. Employer must:
• Assess the Risk
• Reduce risks to
lowest practicable
level
• Keep records and
make them available
• Buy Low Vibration
equipment
Below action level
A(8) is below 2.5m/s
Or 100 points
45. Employer must:
• Identify all employees at
risk with an assessment
• Reduce Exposure
duration
• Use warning signs
• Review any changes to
levels
• Inform employees of risk
• Provide training /
education
• Control Measures
Action level
A(8) is Above 2.5m/s
Or 100 points
46. Employer must:
• Immediate action to
prevent exposure
• Reduce exposure
duration
• Use warning signs
• Inform employees of risk
• Provide training /
education
• Control Measures
• Health Surveillance
Limit value level
A(8) is Above 5m/s
Or 400 points
