Solutions for Risk Reduction

Shaun Knott

Casella Directive 2003/10/EC

Published Feb 15th 2003

Revised October 2005

Noise

The basics

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

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

Adding dB’s

80dB + 80dB

Doesn’t

= 160dB

= 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

LCpk

Peak noise is the highest point measured and also has legislation as to its level.

The basics

Laeq to get Lep’dand

LCpk

Employer must:• Reduce risks to

lowest practicable level

• Keep records and make them available including audiometry (if done)

• Buy quiet

Below lower action

• 80dB(A) LEP,d

• LCPK= 135dB

• Take action as in regulations

Lower exposure action

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

• 85dB LEP,d

• LCPK= 137dB

• Take action as in regulations

Upper exposure action

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

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

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

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

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

Two main types of instrument are used to perform workplace noise assessments

• Sound Level Meter (SLM)

• Dosimeter

S.L.M. or Dosimeter?

• Weighs only 68g• Measures Personal

Exposure• No cable• Display & Visual

alarms• 2 Button operation• Automatic

calibration

dBadge

All instruments should be calibrated prior to measurement• CEL-120• Class 1 or 2• Automatically

adjusts for cavity

Calibrators

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?

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

The Results

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?

Hearing protection

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

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

Health &

Safety

87 dB A (Lep’d)70 dB A (Lep’d)

85 dB A (Lep’d)

Available options

Solutions for Risk Reduction

Or

Solutions for Risk Reduction

Lets make it quieter

Engineered noise reduction

Hand arm vibration

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.

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.

What does it look like

European threshold

2.5 m/s²

5 m/s²Limit threshold

Action threshold

European threshold

1st Action

Limit

The basics

One machine used

Exposure Time

Hours worked (8)

Vibration Magnitude in m/sExposure Measurement

More than one machine used

The basics

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.

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/sOr 100 points

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

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

The HSE calender

• Anti Vibration Gloves

• Effective in that they keep hands warm!

A word on PPE

“It is better to have a loose grip than a tight grip” !

Solutions for Risk Reduction

Questions

07730 818267