Registered Office: The Grange, 41 Hurworth Road, Hurworth Place, Darlington DL2 2BN. Watson Wild & Baker Limited (No 06579974) is registered in England & Wales.

OCCUPATIONAL HYGIENE SURVEY FOR WORKPLACE VIBRATION

For

XXX Yyy Zzz

Aaa Bbb

Ccc PPP

Date: 27 May 2009 Job No: OH/MW/2009/05/16

The Grange 41 Hurworth Road

Hurworth Place DARLINGTON

DL2 2BN

01325 720286 admin@wwbltd.co.uk

Watson Wild & Baker Ltd The experts in preventing injuries and ill health

1

PROJECT SHEET

Job No: OH/MW/2009/05/16

Type of Work Undertaken: Occupational Hygiene survey for workplace vibration. At Location: XXX zzz Yyy, Aaa, Bbb, Ccc PPP Requested by: Mr Graham VVV Senior Health & Safety Coordinator

Date of Survey: 27 May 2009 Site Visit Carried Out By: M J Wild MSc BSc

Report Prepared By: M J Wild MSc BSc

Signature …….………….…………………………

Report Issued On: 3 July 2009

Copyright: The format and contents of this report are the copyright of Watson Wild & Baker Ltd. The

contents of this report are for the sole use of XXX. No person may copy the format or

contents of this report except with the written prior permission of Watson Wild & Baker Ltd.

2

CONTENTS

ITEM

SUMMARY 3

ACTION PLAN 4

1.0 INTRODUCTION 7

2.0 OBJECTIVES 7

3.0 LIMITATIONS 7

4.0 WORK PROCESSES, PRACTICES & SOURCES OF EXPOSURE 8

5.0 DISCUSSION OF RESULTS 9

APPENDICES

1. Task Assessment Sheets 11

2. Methodology 13

3. Sampling Results 14

4. Vibration Exposure Calculations 16

5. The Control of Vibration at Work Regulations 2005 20

6. Health Effects of Vibration 24

3

SUMMARY

A vibration survey was carried out for XXX, Units 5, 7 – 15 Yyy, Aaa, Bbb, Ccc on the 27 May 2009.

All of the dig-team operatives are likely to exceed the Exposure Action Value of 2.5 m/s² A(8).

However, none of the operatives are likely to exceed the Exposure Limit Value of 5 m/s² A(8) when

using the measured equipment for the reported usage times.

Based on a worst-case scenario of "finger on trigger" times, it is possible that one operative could carry

out all the tasks for the designated usage times, i.e. 0.25 hours on the circular saw, 0.1 hours on the

Jack hammer & 0.25 hours on the Flat Plate compactor. Using this scenario, a member of one of the

‘Dig-Teams’ could have amassed an exposure points total of 116 points on the day of the survey or a

Total Daily Vibration Exposure A(8) of 3.9 m/s². The sharing of the tasks would reduce the operator’s

potential exposure to below the Exposure Action Value.

On the day of the survey, none of the internal teams could be measured fitting a meter. Hence, the

vibration data from previous surveys undertaken at the Derby site was used to determine exposure time

& magnitude. However, the operatives reported that their exposure profile was drastically different from

that of the Derby operatives. For example, the Bbb operatives never used the 110v hammer drill & they

only occasionally used the 24v drills. Therefore, it is unlikely that members of the Bbb internal teams

would approach the Exposure Action Value of 2.5 m/s² A(8). However, this assumption will need to be

verified during the next survey.

It is recommended that the following action plan be implemented to reduce noise levels and comply

with the Noise at Work Regulations 2005.

4

ACTION PLAN

The following actions are required to prevent and control exposures:

Serial Action Required Individual responsible for

taking action

Implementation

date Remarks

1.1 Ensure that the provided gloves are suitable for their intended use.

1.2 Rotate operatives within a team so that exposure to the higher magnitude

vibration is reduced.

1.3 The site teams should be given appropriate information, instruction & training on how to recognise where and when vibration protection should be worn.

5

The following actions are required to ensure that prevention & control measures remain effective:

Serial Action Required Individual responsible for

taking action

Implementation

date Remarks

2.1

Consider features such as noise & vibration reduction when replacing old equipment.

2.2

Managers must ensure that equipment is maintained in a good condition to ensure that the vibration generation is minimised.

2.3

Managers and supervisors must ensure that controls are applied and safe working practices are followed (e.g. the wearing of appropriate vibration protection when using certain machines).

2.4

The site teams are provided with vibration cumulative exposure points charts. The Company must ensure that these charts are maintained daily and that the exposure points for each machine remain valid.

6

The following actions are required to comply with the law:

Serial Action Required Individual responsible for

taking action

Implementation

date Remarks

3.1

A copy of the vibration results must be included in risk assessments and personal medical records.

3.2

The risk assessment must be reviewed & if necessary amended, if there is any significant alteration to the process (e.g. new machinery, different work patterns etc).

3.3

Vibration measurements must be repeated if there is any significant alteration to the process (which may include the purchasing of new equipment).

7

1.0 INTRODUCTION

This survey was carried out for XXX, Units 5, 7 – 15 Yyy, Aaa, Bbb on the 27 May 2009, at the request of Mr

Graham Warbrick, Senior Health & Safety Coordinator.

The Company specialises in the fitting and repairing of water regulation & monitoring devices for both the

private and domestic markets.

The purpose of the survey was to determine operator exposure to vibration whilst undertaking work on site.

This survey was undertaken during the day shift with normal manufacturing operations being carried out.

2.0 OBJECTIVES

The objectives of the survey were to:

i) Identify the sources and routes of exposure to vibration in the work areas in operation at the time of the

survey.

ii) Evaluate the risks, whether real or potential;

iii) Assess current working practices to identify those that could potentially increase exposure;

iv) Evaluate current measures used to prevent or control exposures; and

v) Make recommendations where appropriate, having regard to current legislation and best practice.

3.0 LIMITATIONS

Whilst we have exercised reasonable skill and care in carrying out this work, the report reflects working

conditions and practices witnessed by the consultant at the time of the survey. It does not claim to be an

exhaustive list of all potential hazards present at the time of the visit.

The report and any subsequent recommendations are advisory and are provided to assist the client in

complying with their statutory duties. They do not remove the client's legal obligations towards their employees

and other persons affected by their undertaking.

8

4.0 WORK PROCESSES, PRACTICES & SOURCES OF EXPOSURE

The Company operates an 8-hour shift, which ranges between 07:00 - 16:00. Due to the nature of the work

(i.e. travelling from site to site carrying out repairs etc.), breaks are taken as and when appropriate.

Measurements were taken during the day shift with normal fitting and repair operations being carried out.

The various site teams were responsible for fitting new water meters in domestic properties (both new build &

pre-occupied premises) as well as, checking and if necessary repairing or replacing meter chambers. All the

operatives visited on site were seen to be wearing the provided hearing protection (Warrior 14M ear defenders)

and padded gloves when using the larger items such as; the breaking machines, compactors, circular saws &

large drills.

The main sources of vibration in the areas surveyed emanated from; (1) the use of powered hand-held circular saws;

(2) the use of jack hammers;

(3) the use of compaction tools;

(4) drilling into brickwork;

(5) the portable generator;

As Hygienics Consultants, our expertise is in the identification, evaluation and control of physical, chemical,

biological and ergonomic health hazards in the workplace. During the initial appraisal, we identified that there

could be a potential health risk from exposure to dust, noise, vibration & manual handling issues. The only

issue addressed by this report was exposure to vibration. Task evaluation sheets are contained in appendix 1.

Vibration exposures were evaluated using the methodology contained in appendix 2. The monitoring results

are contained in appendix 3 and were compared against the relevant legal provisions (The Control of Vibration

at Work Regulations 2005), a summary of which are contained in appendix 5. Vibration exposure calculations

are contained in appendix 4. Health effects of vibration are summarized in appendix 6.

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5.0 DISCUSSION OF RESULTS

The Control of Vibration at Work Regulations 2005 came into force on the 6 July 2005. (Regulation 4) Exposure Limit Values & Action Values: For Hand-Arm Vibration: The daily Exposure Limit Value is 5 m/s² A(8); The daily Exposure Action Value is 2.5 m/s² A(8), The daily exposure should be ascertained on the basis set out in Schedule 1 Part I of the Regulations. The daily exposure limit value is the maximum amount of vibration an employee may be exposed to on any single day (see regulation 6(4)). The daily exposure action value is the level of exposure to vibration above which you are required to take certain actions to reduce exposure (see regulations 6(2), 7(1)(b) & 8(1)(b)). Vibration Exposure Assessment In order to provide an assessment of the vibration an individual is exposed to, it is necessary to know the duration of typical daily usage as well as the vibration values for each tool used. The conventional way to calculate the operator's daily vibration exposure A(8) uses the total vibration produced by the tool (‘vector sum value’) and the contact time (‘finger on trigger’) in a typical working day. As the exposure time is not directly proportional to A(8), it is difficult to evaluate the operator exposures for different periods of use or where operators use more than one tool in a day. An exposure points system simplifies the risk assessment procedure. The exposure point values equivalent to the action and limit values in the current guidance are as follows: Exposure Action Value of 2.5 m/s² A(8) = 100 points Exposure Limit Value of 5 m/s² A(8) = 400 points

All of the dig-team operatives are likely to exceed the Exposure Action Value of 2.5 m/s² A(8). However, none

of the operatives are likely to exceed the Exposure Limit Value of 5 m/s² A(8) when using the measured

equipment for the reported usage times.

Hand-arm vibration syndrome is a widespread industrial disease affecting tens of thousands of workers. Its

best-known effect is vibration white finger (VWF). Any vibrating tool or process, which causes tingling or

numbness after 5 to 10 minutes of continuous use is suspect.

10

Manufacturers and suppliers of high vibration tools (greater than 2.5 m/s²) have a legal duty to provide the

appropriate information. Severn Trent Metering Service should ensure that a purchasing policy is in place and

request information on vibration levels and control measures designed into equipment. The most effective

long-term measure to reduce vibration is to buy low vibration tools as existing equipment wears out and is

replaced.

Based on a worst-case scenario of "finger on trigger" times, it is possible that one operative could carry out all

the tasks for the designated usage times, i.e. 0.25 hours on the circular saw, 0.1 hours on the Jack hammer &

0.25 hours on the Flat Plate compactor. Using this scenario, a member of one of the ‘Dig-Teams’ could have

amassed an exposure points total of 116 points on the day of the survey or a Total Daily Vibration Exposure

A(8) of 3.9 m/s². The sharing of the tasks would reduce the operator’s potential exposure to below the

Exposure Action Value.

On the day of the survey, none of the internal teams could be measured fitting a meter. Hence, the vibration

data from previous surveys undertaken at the Derby site was used to determine exposure time & magnitude.

However, the operatives reported that their exposure profile was drastically different from that of the Derby

operatives. For example, the Bbb operatives never used the 110v hammer drill & they only occasionally used

the 24v drills. Therefore, it is unlikely that members of the Bbb internal teams would approach the Exposure

Action Value of 2.5 m/s² A(8). However, this assumption will need to be verified during the next survey.

11

Appendix 1

TASK ASSESSMENT SHEETS

TASK ASSESSMENT SITE TEAMS

Ref no: OH/MW/2009/05/16 – 1 Sheet 1 of 2

The Task Task Description

Checking, repairing & replacing water meters.

Task Environment

The site teams can work inside & outside domestic properties, as well as on public highways.

How many people carry out this task? 2 personnel on the Dig-Teams & 1 on each of the Internal-Teams.

What are the hazardous agents associated with this task?

Noise & Hand arm vibration. Ergonomic issues from handling heavy equipment in awkward positions etc.

Health Risks What are the significant health effects from the hazardous agents?

Noise induced hearing loss & hand arm vibration syndrome. Muscular-skeletal disorders.

Is it possible that the levels, duration & frequency of exposure could make a significant contribution to ill health?

Yes No

For the dig teams, noise exposures are consistently over the Upper Exposure Action Value of 85 dB (A) LEP,d. Some tasks (operating the circular saw & flat plate compactor) gave intermittent noise exposures that exceeded 100 dB (A). The personal vibration exposures of the dig teams are likely to exceed the Exposure Action Value of 2.5 m/s². For the internal teams, noise exposures are consistently below the Lower Exposure Action Value of 80 dB (A) LEP,d. The personal vibration exposures of the internal teams are unlikely to exceed the Exposure Action Value of 2.5 m/s².

Compliance What specific regulations apply to this work activity?

Vibration at Work Regulations 2005. Noise at Work Regulations 2005.

Has a suitable & sufficient risk assessment been carried out?

Yes This report represents a suitable & sufficient Risk Assessment.

Has the workers’ exposure to the hazardous agents been monitored with a suitable method where appropriate?

Yes See this report & previous reports (H383, 449).

Has suitable health surveillance been provided where appropriate?

No Yes

Audiometry should be provided as part of a hearing conservation programme. The operatives receive regular screening for the effects of vibration on their hands & arms.

Have appropriate records been retained?

Yes

There was evidence that the company had kept records pertaining to Noise & vibration exposure & personal protective equipment (hearing protection).

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TASK ASSESSMENT SITE TEAMS

Ref no: OH/MW/2009/05/16 – 1 Sheet 2 of 2

Prevention Has all reasonably practical measures been taken to prevent exposure?

Yes The rotation of the staff undertaking the noisy & high vibration tasks should ensure that noise & vibration exposures are below the Upper Exposure Action Value for noise & the Exposure Limit Value for vibration. Unfortunately, many operations are carried out on public highways, consequently, significant noise exposure could emanate from traffic noise. The Company also operates a purchasing policy & undertakes preventative maintenance on machinery, motors, powered hand tools etc. that will minimise noise & vibration generation from wearing parts.

Control Measures Have all necessary steps been taken to ensure that exposure was adequately controlled?

No Yes

The Dig teams are not provided with ear defenders that will reduced the noise received at the ear to below the Exposure Limit Value. Suitable gloves are provided for work in cold weather, which will minimise damage from hand-arm vibration. The operatives are supplied with a vibration exposure points chart which details how much time each operative can operate any particular piece of equipment.

Has suitable and sufficient personal protective equipment (PPE) been provided?

Yes The operatives were provided with appropriate personal protective equipment, which included; disposable masks, suitable gloves; overalls; steel toe-capped boots; safety glasses, ear defenders (Warrior 14M ear defenders) & high-visibility vests.

Has all reasonable steps been taken to ensure that the existing control measures were properly used & applied?

Yes The team leaders ensure that hear protection is worn & that data is recorded in the vibration exposure charts.

Has all reasonable steps been taken to ensure that the existing control measures were properly maintained?

Yes Hearing protection and gloves were made available to those individuals requesting it. PPE was changed as & when necessary. Ear defenders were kept clean & safe in personal boxes & bags when not in use.

Management Has all necessary steps been taken to ensure that workers understood the health risks associated with the hazardous agents?

No Persons need to be trained in the health hazards associated with exposures to noise & vibration.

Has all necessary steps been taken to ensure that workers understood how to safeguard their own & others health?

Yes Observation of the workplace activities indicated that the operatives knew how to safeguard their own & others health by the manner in which they worked.

Has all necessary steps been taken to protect workers from exposures to hazardous agents in an accident, incident or emergency?

N/A

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Appendix 2

METHODOLOGY

A PCB Piezotronics Tri-axial Accelerometer fitted with a Bruel & Kjaer mechanical filter (UA 0559) was

connected to a Quest Technologies Hand Arm Vibration Meter (HAV Pro), in order to take vibration

acceleration measurements.

All the vibration measurements were made in three orthogonal directions using an accelerometer attached with

a lightweight fixture, rigidly clamped directly to the handle of the tool, as close as possible to the position of the

operator's hand. Prior to taking any measurements, initial checks confirmed satisfactory operation of the

equipment. Thereafter, careful checks were made whilst taking the measurements to monitor the vibration

signals and check for overload of the instrumentation. All measurements were made under real operating

conditions.

All measurements were made in accordance with British Standard BS EN ISO 5349-2:2002 "Mechanical

Vibration - Measurement and Assessment of Human Exposure to Hand-Transmitted Vibration" Practical

guidance for measurement at the workplace. The instrument was calibrated before use in accordance with the

requirements of the manufacturer’s instructions. The accelerometer was carefully placed on the handle of the

tool, rigidly fixed with an adjustable band clamp, and aligned in accordance with the axes specified in the

Standard.

The instantaneous vibration value was monitored during each test to ensure the level remained relatively

steady. For each test, the measurement was carried out for sufficient time to obtain an accurate representation

of the vibration value. The frequency weighted RMS vibration ahw was representative of continuous ("finger-on-

trigger") tool operation. No allowance was made for time spent loading, unloading, work piece preparation or

other periods of time/work pattern, which may reduce operator exposure. Instrumentation overload can occur

when measuring hand-arm vibration of percussive or roto-percussive power tools such as breakers, impact

wrenches, needle guns, hammer drills, etc. Overload of the instrument chain (accelerometer or meter input

amplifier) causes distortion of the vibration acceleration signal.

When the results show that meter overload has occurred, the measured vibration values may be inaccurate

and should only be used as a rough guide. There were no overloads of the instrumentation during the survey.

14

Appendix 3

SAMPLE RESULTS

Table 1: Equipment & operating conditions.

Description Model Plant No. Task Accessories Tool Specification

Circular saw Stihl TS 410 Cutting asphalt pavement

Diamond tipped asphalt blade

4960 rpm

Jack Hammer DeWalt D25901 Breaking concrete pavement

2” chisel 110v, 10A, 1.1kW

Flat Plate Compactor Belle PCL 320 Compacting asphalt 3 kW, 4 hp, 60 kg, 132 lbs

Table 2: Measured frequency weighted rms vibration acceleration for each tool.

Description Model Handle 1 x1 y1 z1 Handle 2 x1 y1 z1 m/s² m/s² m/s² m/s² m/s² m/s²

Circular saw Stihl TS 410 Trigger 4.3 2.1 5.9 Support 6.4 3.2 4.9

Jack Hammer DeWalt D25901 Main 1.6 0.7 1.4 Support

Hammer Drill* Bosch GBH 24v* Trigger* 0.2 14.8 6.0 Support* 0.4 10.5 4.7

Hammer Drill* Makita 110v* Trigger* 0.2 8.5 4.5 Support* 0.2 6.1 11.1

Flat Plate Compactor Belle PCL 320 Main 9.9 5.7 5.2

* = from previous reports, unable to measure during this survey. Table 3: Daily exposure for reported single tool operating time.

Description Model Finger on Trigger time

Highest Axis

Vector Sum Daily exposure A(8)

Task exposure

10% Risk of finger

blanching

hours m/s² m/s² m/s² points years

Circular saw Stihl TS 410 0.25 6.4 8.6 1.5 37 >8

Jack Hammer DeWalt D25901 0.1 1.6 2.2 0.2 1 >8

Hammer Drill Bosch GBH 24v 0.25 14.8 16.0 2.8 128 >8

Hammer Drill Makita 110v 0.1 11.1 12.6 1.4 31 >8

Flat Plate Compactor Belle PCL 320 0.25 9.9 12.5 2.2 78 >8 Notes: 1. Measured vibration values are for typical operations undertaken on the day of the survey. 2. Daily Exposure & Exposure Points (displayed only for vector sum assessment) are highly dependent on accurate

‘finger-on-trigger’ time. 3. The calculated ‘10% Risk of finger blanching’ value is only applicable between 1 – 8 years, & is a rough guide only.

15

Table 4a: Daily hand-arm vibration exposure for the External ‘Dig-Team’ personnel.

External ‘Dig Team’ Personnel

Exposure Points per hour

Time to reach Exposure Action

Value

2.5 m/s²

Time to reach Exposure Limit

Value

5 m/s²

Exposure Duration

Partial Exposure A(8)

Partial Exposure

mins mins mins m/s² points Circular saw to cut asphalt. 148 40 162 15 1.5 37 Jack hammer to break hard-core. 10 620 2476 6 0.2 1

Flat Plate Compactor. 312 19 77 15 2.2 78

Daily Exposure m/s² A(8) 3.9 Total Exposure Points 116

Table 4b: Daily hand-arm vibration exposure for the Internal ‘New-Supplies’ personnel.

Internal ‘New Supplies’ Personnel

Exposure Points per hour

Time to reach Exposure Action Value 2.5 m/s²

Time to reach Exposure Limit

Value

5 m/s²

Exposure Duration

Partial Exposure A(8)

Partial Exposure

mins mins mins m/s² points Bosch Hammer Drill. 512 11 46 15 2.8 128

Makita 110v Hammer Drill. 318 18 75 6 1.4 31

Daily Exposure m/s² A(8) 3.1 Total Exposure Points 159

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Appendix 4

Vibration Exposure Calculations

Vibration levels are measured on each handle of the tool in mutually perpendicular axes, which gives three vibration acceleration values ahwx, ahwy and ahwz in m/s². These are the root-mean-square (RMS) acceleration values at the vibrating surface in contact with the hand and frequency-weighted using the weighting function Wh. This is a low frequency band pass filter defined in British Standard BS EN ISO 5349-1 : 2001. Vibration at frequencies below 2Hz and above 1500Hz is not thought to cause damage. Vibration measurements were taken in all three axes in accordance with "The Control of Vibration at Work Regulations 2005". The regulations require that the ‘vector sum’ vibration acceleration value is used for the calculation of the daily personal vibration exposure. 4.1 Measured Vibration

Vector Sum ahv = √ (ahwx)² + (ahwy)² + (ahwz)² . . . . . . . . . Equation 1 When two handles are fitted and held, the vector sum number to use is the higher value. The ‘vector sum’ or ‘vibration total value’ are the same common terms for what is more accurately called the ‘root-sum-of-squares’. 4.2 Daily Personal Vibration Exposure – (single operation or tool use)

Daily Personal Vibration Exposure A(8) = ahv × √ T/T0 . . . . . . . .Equation 2 = ahv × √ T/8

Where T is the number of hours for usage per day. This is the total time for contact with the vibrating surface or handles (i.e. "finger-on-trigger" time),

and T0 is the reference duration of 8 hours.

Note: The number of hour’s usage T and the reference duration T0 must be in the same units (i.e. T in hours then T0 = 8, T in minutes then T0 = 480, T in seconds then T0 = 28,800).

17

4.3 Daily Personal Vibration Exposure – (multiple operation or tool use) Where there are multiple exposures (i.e. using different tools or carrying out different operations), then the daily personal vibration exposure is derived by adding the individual exposures as follows. Multiple Tool Usage A(8) = √ A1(8)2 + A2(8)2 + . . . An(8)2 etc . . . . . . . Equation 3 The individual An (8) values are the partial vibration exposure values for each source for the individual user of a range of equipment. 4.4 Weekly Average of Daily Personal Vibration Exposure When the daily exposure is usually below the exposure action value (2.5 m/s²), but varies markedly and may occasionally exceed the exposure limit value (5 m/s²), then the forthcoming Vibration Regulations allow the exposure to be averaged over a week for the purposes of applying the exposure limit value. Weekly A(8)week = √ 1/5[(Amon(8)2 + Atue(8)2 + Awed(8)2 + Athur(8)2 + Afri(8)2 + Asat(8)2 + Asun(8)2

Equation 4

Amon(8) to Asun(8) are the daily exposures for all seven consecutive days. The value A(8)week (normalised to a 5 day working week) may then be compared with the exposure limit value in the usual way. 4.5 Exposure Action and Limit Values Exposure Action Value 2.5 m/s² Exposure Limit Value 5 m/s² Note: These values are based on ‘vector sum’ measurements and are normalised to an 8-hour reference period. A vector sum vibration dose of 5 m/s² A(8) should not be considered a safe level. Studies suggest that symptoms of the hand-arm vibration syndrome are rare in persons exposed with an 8 hour energy-equivalent vibration total value A(8) at a surface in contact with the hand of less than 2 m/s², and unreported for A(8) values of less than 1 m/s². {Extract from Annex C (Informative) of BS EN ISO 5349-1 : 2001}.

18

4.6 Single Tool Running Time or Time to Reach Exposure Value Some employers find it useful to monitor and control vibration exposure by specifying a running time limit on individual tools. When only one vibrating tool is used in a single day, the single tool running time (M) which does not exceed any action or limit value, can be calculated from the measured vector sum vibration value ahv, provided there is no other exposure to high vibration tools during the working day. M = (action value/ ahv )² × M0 . . . . . . . . . . . . . . . . . . . . . . Equation 5 = (2.5/ ahv )² × 480

Where M is the single tool running time in minutes, M0 is the reference duration of 480 minutes,

and the chosen action value is 2.5 m/s². Alternative the limit value of 5 m/s² may be used as necessary for the required evaluation. Note: The running time M and the reference duration M0 must be in the same units (i.e. M in minutes then M0 = 480,

M in hours then M0 = 8). Do not use this equation for very large accelerations (and extrapolate M for short durations) as such exposures can be associated with other acute injuries to the hand-arm system. 4.7 Exposure Points System Where there are multiple exposures due to the use of different tools, a more sophisticated system is required to manage daily exposure - hence the following points system. Exposure Points n = {ahv / 2.5 }² × t/8 × 100 . . . . . . . . . . Equation 6

Where t is the exposure time in hours. The above equation can be used to calculate exposure points for each individual tool/operation. The total exposure is then obtain from a simple addition of the points for each tool/operation and can be compared with the relevant action/limit value to determine the management actions required. Exposure Action Value 2.5 m/s² = 100 exposure points 4 m/s² = 256 exposure points Exposure Limit Value 5 m/s² = 400 exposure points For any particular tool the number of exposure points accumulated in an hour is as follows. One Hour Exposure Points n1 hour = 2 × (ahv)² . . . . . . . . . . Equation 7

19

One hour exposure points is a very powerful and useful method which can easily be factored for the actual running time of each tool and processed as above for multiple tool use. 4.8 Prevalence of Finger Blanching A tentative relationship between vibration exposures and finger blanching is presented in Annex C (referred to as informative as it provides guidance alone) of BS EN ISO 5349 : 2001.

Years for 10% Risk of Finger Blanching

Dy = 31.8 / A(8)1.06 = (approximately 32 / A(8)) . . . .Equation 8

Where A(8) is the daily personal vibration exposure, and Dy is the group mean total (lifetime) exposure duration, in years.

The calculated value is only applicable between 1 and 8 years. The years for 10% risk of finger blanching is a rough statistical guide for a group of exposed persons and cannot predict the risk of finger blanching for an individual within a group (i.e. it provides a rough guide for an ‘average’ person) based on the tentative relationship. Note: The state of knowledge of the dose effect relationship is very limited. The probability of a vibration exposed

individual developing finger blanching depends not only on the risk factors, but also on individual susceptibility and behaviour.

20

Appendix 5

Summary of the Control of Vibration at Work Regulations 2005

The Control of Vibration at Work Regulations 2005 requires employers to prevent or reduce risks to health and

safety from exposure to vibration at work. The Control of Vibration at Work Regulations requires you as an

employer to:

• Assess the vibration risk to your employees;

• Take action to reduce vibration exposure that produces those risks

• Decide if employees are likely to be exposed above the:

o Daily exposure action value (EAV) and if they are:

introduce a programme of controls to eliminate risk, or reduce exposure to as low a level as is

reasonably practicable;

o Daily exposure limit value (ELV) and if they are:

take immediate action to reduce their exposure below the limit value;

• Make sure the legal limits on vibration exposure are not exceeded;

• Provide information and training to employees on health risks and the actions you are taking to control

those risks;

• Carry out health surveillance (regular health checks) where there is a risk to health;

• Consult your trade union safety representative or employee representative on your proposals to control

risk and to provide health surveillance

• Keep a record of your risk assessment and control actions;

• Keep health records for employees under health surveillance;

• Review and update your risk assessment regularly.

Vibration Levels

The purpose of the Control of Vibration at Work Regulations 2005 is to make sure that people do not suffer

damage to their health from hand-arm vibration – so controlling the risks from exposure to hand-arm vibration

should be where you concentrate your efforts. The Control of Vibration at Work Regulations 2005 requires you

to take specific action when the daily vibration exposure reaches a certain action value.

21

Where there are things you can do to reduce risks from vibration that are reasonably practicable, they should

be done. The exposure action value (EAV) is a daily amount of vibration exposure above which employers are

required to take action to control exposure. For hand-arm vibration the EAV is a daily exposure of 2.5 m/s²

A(8). Where your assessment shows that your employees are likely to be exposed at or above the Exposure

Action Values, you must put in place a planned programme of vibration control. However, where vibration

exposures are below the EAV, risks are low and so you would only be expected to take actions, which are

relatively inexpensive and simple to carry out.

There is also a level of vibration exposure that must not be exceeded. This is called the exposure limit value.

The exposure limit value (ELV) is the maximum amount of vibration an employee may be exposed to on any

single day. For hand-arm vibration the ELV is a daily exposure of 5 m/s² A(8). It represents a high risk above

which employees should not be exposed.

When you have identified who is at risk, you must do all that is reasonable to control the risk. First, prepare an

action plan for and deal with the high-risk work tasks. Then address the medium and lower-risk activities.

Risk Controls

Risk controls include:

Alternative work methods

• Look for alternative work methods which eliminate or reduce exposure to vibration. Your trade

association, other industry contacts, equipment suppliers and trade journals may help you identify

good practice in your industry.

• Mechanise or automate the work.

Equipment selection

• Make sure that equipment selected or allocated for tasks is suitable and can do the work efficiently.

Equipment that is unsuitable, too small or not powerful enough is likely to take much longer to

complete the task and expose employees to vibration for longer than is necessary.

• Select the lowest vibration tool that is suitable and can do the work efficiently.

• Limit the use of high-vibration tools wherever possible.

22

Purchasing policy for replacing old equipment and tools

Work equipment is likely to be replaced over time as it becomes worn out, and it is important that you choose

replacements, so far as is reasonably practicable, which are suitable for the work, efficient and of lower

vibration.

• Discuss your requirements with a range of suppliers.

• Check with suppliers that their equipment is suitable and will be effective for the work, compare

vibration emission information for different brands/models of equipment, ask for vibration information

for the way you plan to use the equipment, and ask for information on any training requirements for

safe operation.

• Get your employees to try the different models and brands of equipment and take account of their

opinions before you decide which to buy.

• Find out about the equipment’s vibration reduction features and how to use and maintain the

equipment to make these features effective.

• Make sure your organisation has a policy on purchasing suitable equipment, taking account of

vibration emission, efficiency and your specific requirements.

• Train purchasing staff on the issues relating to vibration so that they can deal effectively with

equipment suppliers.

Workstation design

• Improve the design of workstations to minimise loads on employees' hands, wrists and arms caused by

poor posture.

• Use devices such as jigs and suspension systems to reduce the need to grip heavy tools tightly.

Maintenance

• Introduce appropriate maintenance programmes for your equipment to prevent avoidable increases in

vibration (following the manufacturer’s recommendations where appropriate).

• Do not use blunt or damaged concrete breaker and chipping hammer chisels and replace consumable

items such as grinding wheels, so that equipment is efficient and keeps employee exposure as short

as possible.

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Work schedules

• Limit the time that your employees are exposed to vibration.

• Plan work to avoid individuals being exposed to vibration for long, continuous periods – several shorter

periods is preferable.

• Where tools require continual or frequent use, introduce employee rotas to limit exposure times (you

should avoid employees being exposed for periods which are long enough to put them in the high risk

group (see ‘High risk (above the ELV)’).

Clothing

• Provide your employees with protective clothing when necessary to keep them warm and dry. This will

encourage good blood circulation which should help protect them from developing vibration white

finger.

Gloves can be used to keep hands warm, but should not be relied upon to provide protection from vibration.

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Appendix 6

Health Effects of Vibration

Hand Transmitted Vibration Personnel whose hands are regularly exposed to vibration or repeated shock may suffer from symptoms due to

pathological effects on the peripheral vascular & nervous systems, muscles and other tissues of the hand &

arm. The symptoms are collectively known as hand-arm vibration syndrome (HAVS). The five types of

disorder {Circulatory, Bone & Joint, Neurological, Muscle & Other} may be interconnected, for example; more

than one disorder can affect a person at the same time and it is possible that the presence of one disorder

facilitates the appearance of another.

Vascular Effects (vibration-induced white finger) Episodic finger blanching is the characteristic vascular sign known as ‘vibration white finger (VWF)’, ‘dead

finger’ or ‘dead hand’. The fingertips are usually the first to blanch, but the affected area may extend to all of

one or more fingers with continued vibration exposure. Attacks of blanching are precipitated by cold, and as

such, usually occur in cold conditions or when handling cold objects. The blanching lasts until the fingers are

re-warmed & vasodilation allows the return of the blood circulation. Tissue ischaemia occurs during the period

of spasm. This leads to an exaggerated return of blood flow and painful red throbbing fingers (reactive

hyperaemia). During attacks the sufferer may complain of numbness, pain & cold as well as reduced manual

dexterity. Many years of vibration exposure often occurs before the first attack of blanching is noticed.

Affected persons often have other signs and symptoms, such as numbness & tingling. There are other

conditions that can cause similar signs & symptoms to those associated with VWF, for example Raynaud’s

disease (also known as constitutional white finger). Often, medical examination is needed to distinguish

between the two phenomena.

Neurological Effects

Effects of hand-transmitted vibration such as; numbness, tingling, elevated sensory thresholds for touch, pain &

reduced nerve conduction velocity, are now recognised as separate effects of vibration and not merely as

symptoms of VWF. The nerve damage can be disabling, making it difficult to feel and to work with small

objects.

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Muscular Effects

The research literature includes several reports of muscular atrophy among users of vibrating tools. More

commonly, workers exposed to hand-transmitted vibration report difficulty with their grip, including – reduced

dexterity, reduced grip strength and locked grip.

Muscle activity may be of great importance to tool users, since a secure grip can be essential to the

performance of the job and safe control of the tool. The presence of vibration on a handle may encourage the

adoption of a tighter grip than would otherwise occur, and a tight grip may increase the transmission of

vibration to the hand. Carpal tunnel syndrome, a disorder of the hand and arm giving rise to tingling,

numbness, weakness, pain & night waking can be caused by exposure to vibration.

Articular Effects

Many surveys of the users of hand-held tools have found evidence of bone & joint problems: most often among

men operating percussive tools. It has been speculated that some characteristics of these tools, possibly low

frequency shocks, may be responsible. Some of the reported injuries relate to specific bones and suggest the

existence of cysts, vacuoles, decalcification, degeneration or deformity of the carpal, metacarpal or phalangeal

bones. Osteoarthrosis & Olecranon spurs at the elbow, and other problems at the wrist and shoulder were also

documented.

Other Effects

Effects of hand-transmitted vibration may not be confined to the fingers, hands and arms: many studies have

found a high incidence of problems such as headaches & sleeplessness among tool users.

The table below relates the daily weighted vibration exposure level A(8) to the number of years' exposure that

may cause finger blanching in about 10% of the vibration exposed population.

Exposure in years 1 2 4 8 Daily Vibration Exposure A(8) m/s² 26 14 7 3.7

Note: There is considerable uncertainty in these results. The state of knowledge of the dose effect relationship is limited. The probability of a vibration exposed individual developing finger blanching depends on numerous factors, one of which is individual susceptibility.

This relationship is only tentative, so it should be treated only as a rough guide for an average person.

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The table below gives a range of vibration magnitudes, together with the corresponding exposure times, which

would result in exposures at the Exposure Action Value (2.5 m/s² A(8)) and the Exposure Limit Value (5 m/s²

A(8)).

Vibration magnitude (m/s²). 2.5 3.5 5 10 14 20

Time to reach Exposure Action Value (hours). 8 4 2 0.5 0.25 8 min

Time to reach Exposure Limit Value (hours). >24 16 8 2 1 0.5