Introduction to Hand Arm Vibration in anOccupational Setting

jane.coombs@working-well-solutions.com

Contents• Introduction • What is vibration?• How is vibration measured?• Hand-arm vibration syndrome • Regulations• Control of Vibration at Work Regulations 2005• Employers legal duties• Health surveillance guidance• Further Reading

IntroductionHand-arm vibration (HAV) widespread hazard for employees in many industries and occupationse.g. construction/demolition, mining, quarrying, forestry, shipbuilding/repair, foundries, public utilities, railways and aircraft manufacture

• Percussive tools• Caulking tools• Riveting tools• Road breakers

• Rotary tools• Grinders• Sanders• Burring tools

• Forest and garden tools• Chain saws• Motor mowers

• Others• shoe-pounding machines• Motorcycles handle bars

Introduction• Prolonged and regular exposure to vibration can affect the

operators health• 5,000,000 employees exposed• 2,000,000 employees have clear risk of developing disease (HSE 2005)

• Risks from vibration can be controlled and employees protected • To protect employees and to comply with the Vibration Regulations,

employers need to assess the risks from vibration and control them.

What is vibration?• Vibrations arise when a body oscillates due to external and internal

forces

• the handle of a machine or the surface of a work piece vibrates rapidly

• this motion is transmitted into the hand and arm

What is vibration?

Vibration is defined by the • magnitude - acceleration

(m/s2 r.m.s)• frequency (Hz)

What is vibration?Vibration is measured in three planes:

The axes are dependent on the position of the hand relative to the vibrating object – so should

always be noted

X Y Z

How is vibration measured?• Instrumentation:

• HAV measuring equipment should comply with the EN ISO 8041:2005 specifications for hand-arm vibration measuring equipment

• Calibrate and monitor instrumentation for over-loading (e.g. vibration transducers).

• Measurement method• Methods defined in EN ISO 5349-1:2001• Carefully select mounting method as outlined in EN ISO 5349-2:2001

Hand-arm vibration syndrome• Neurological disorders

• Numbness• Tingling• Loss of manual dexterity

• Vascular disorders• VWF

• secondary Raynaud’s phenomenon

• Musculo-skeletal disorders• Reduced grip strength• Bone disorders

• Other - Carpal tunnel syndrome

Symptoms

Mild HAVS

• Episodic blanching

• Numbness

• Tingling

Severe HAVS• Cyanosis

• Skin necrosis

• Gangrene

A hand during an episode of blanching

Regulations

• Control of Vibration at Work Regulations 2005• European Physical Agents (Vibration) Directive (Directive

2002/44)

• RIDDOR 1995

Control of Vibration at Work Regulations 2005

• Exposure action level (EAV)• ‘Daily amount of vibration exposure above which employers are required to

take certain actions to control exposure’• Greater the exposure level, greater the risk, the more action employers will

need to take to reduce the risk• EAV is 2.5 m/s2 A(8)

• Exposure limit value (ELV)• The ‘maximum amount of vibration an employee may be exposed to on any

single day’• ELV is 5 m/s2 A(8)• It represents a high risk above which employees should not be exposed.

Control of Vibration at Work Regulations 2005

Control of Vibration at Work Regulations 2005

• Employers legal duties:• Assess the vibration risk to employees• Decide if employees are likely to be exposed above the daily EAV

• If yes, introduce programme of controls to eliminate risk

• Provide health surveillance to those regularly exposed above the EAV or at risk

Control of Vibration at Work Regulations 2005

• Decide if employees are likely to be exposed above the daily ELV• If yes, take immediate action to reduce their exposure below the limit value• Refer to publications on strategies to reduce vibration exposure e.g.

alternative work methods, equipment selection, purchasing policy for replacing old tools, work schedules, clothing, workstation design, maintenance.

Employers legal duties:

• Information and training on health risks • Keep a record of risk assessment and control actions• Keep health records for employees under health

surveillance• Review and update risk assessments regularly• Consult employee rep. on proposals to control risk and

provide health surveillance

Control of Vibration at Work Regulations 2005 L140 Guidance

• Part 3: Practical control of vibration exposure and risk• Eliminate vibration exposure in the work process

• Reduce exposure by mechanisation

• Select equipment for reduced vibration exposure

• Manage vibration exposure

• Maintain tools and equipment

• Reduce the level of exposure to the hand

• Reduce the period of exposure

• Gloves and warm clothing

• Information and training for operators and supervisors

• Obtaining competent advice or a consultant

Part 5: Tiered approach to health surveillance for HAVS

Initial or baseline assessment

Simple self-administered questionnaire returned to responsible person or qualified person

Targeted assessment

Qualified person (OHN or doctor)

A presumptive diagnosis can be made

Formal Diagnosis

Doctor

RIDDOR report / fitness to work recommendations

Optional

Standardised tests

Not part of routine health surveillance

Useful for studying progression of disease

Tier 1

Tier 3

No symptoms

Fit to work

If symptoms reported or suffers from relevant vascular or neurological disorder

Annual (screening) questionnaire

Tier 2

3 yearly assessment if no symptoms reported by

questionnaire

Health Surveillance

• Questionnaire screening• Diagnosis

• History of symptoms

• Exclude primary Raynaud’s phenomenon

• Exclude other known causes of secondary Raynaud's phenomenon

• Establish that sufficient vibration exposure has occurred

• NB not helped by smoking

Problems

• Episodic nature of attacks

• Subjective history of symptoms

• Subjective history of vibration exposure

• Primary Raynaud’s phenomenon and other causes of secondary Raynaud’s phenomenon

Solution• Stockholm staging• Griffin scoring

• Objective tests:• Specific• Sensitive

Objective measurement

Vascular tests• Finger systolic blood pressures• Rewarming time

Neurological tests• Thermal thresholds• Vibro tactile thresholds• Clinical tactile threshold tests• Nerve conduction velocity

Multi-Channel Plethysmograph

Finger systolic blood pressure

Channel Temperature Monitor

Finger rewarming test

Vibrotactile thresholds test

Vibrotactile Perception Meter

Thermal thresholds test

Thermal Aesthesiometer

Further Reading

Guidance and advice from the HSE at http://www.hse.gov.uk/vibration/• As part of the package which supports the Control of Vibration at

Work Regulations 2005 the HSE have also produced a calculator to assist in calculating exposures for hand-arm vibration.

Hand-arm vibration at work: A brief guide (INDG175)Guide to using the hand-arm vibration calculatorHand-arm vibration calculator [Excel 48KB] Healthy working lives (Scotland) http://www.healthyworkinglives.com/