Hand-Arm Vibration



Introduction

This H&S Update draws your attention to relevant legislation, the need to manage ill-health risks arising from exposure to Hand-arm vibration hazards in the workplace and gives practical advice and guidance on how to keep people safe and sound and comply with relevant legislation.

What are the risks?

Using vibrating tools and equipment in the workplace can lead to Ill health conditions collectively known as Hand-arm vibration syndrome, or ‘HAVs’.  This term is used to describe a range of ill health conditions including ‘Vibration White Finger’, ‘carpel tunnel syndrome’, and tendonitis. Damage is irreversible and leaves employees with lifelong conditions.

Colleagues could be most at risk when:

  • Working in roles that expose them to high levels of vibration, such as highway maintenance, construction, grounds maintenance, vehicle maintenance, and metalworking, etc
  • Using high vibration magnitude equipment including, but not limited to breakers, scabblers, impact wrenches, hammer drills, grinders, disc-cutters, sanders, and compaction equipment, etc.
  • Smoking, as this reduces blood flow and reduces recovery from vibration trauma
  • Having pre-existing neurological (nerve), vascular (circulatory) and musculoskeletal conditions
  • Working in cold and damp environments

Management of Risk and Principles of Prevention:

  • The employer must ensure that risk from the exposure of vibration to his employees is either eliminated at source or, where this is not reasonably practicable, reduced to as low a level as is reasonably practicable
  • Where it is not reasonably practicable to eliminate risk at source and an exposure action value is likely to be reached or exceeded, the employer must reduce exposure to as low a level as is reasonably practicable by establishing and implementing a programme of organisational and technical measures which is appropriate to the activity
  • The measures taken by the employer shall be based on the general principles of prevention and shall include consideration of:
    • Other working methods which eliminate or reduce exposure to vibration
    • Choice of work equipment of appropriate ergonomic design which, taking account of the work to be done, produces the least possible vibration
    • The provision of auxiliary equipment which reduces the risk of injuries caused by vibration
    • Appropriate maintenance programmes for work equipment, the workplace and workplace systems
    • The design and layout of workplaces, workstations and rest facilities
    • Suitable and sufficient information and training for employees, such that work equipment may be used correctly and safely, to minimise their exposure to vibration
    • Limitation of the duration and magnitude of exposure to vibration
    • Appropriate work schedules with adequate rest periods; and the provision of clothing to protect employees from cold and damp

Vibration Exposure

Like all ill health hazards, ‘exposure’ is a product of ‘Strength’ x ‘Time’.

Vibration magnitude is measured and expressed as metres per second per second (m/s2).

Manufacturers provide ‘tool data’ within user manuals, and there are many useful sources of information that can be found on the internet.

Strength

Typical vibration magnitudes are:

  • Breakers – 12 m/s2 +
  • Strimmers, hedge Cutters and Mowers – 6 m/s2 +
  • Wacker Plates – 5 m/s2 +
  • Sanders – 4 m/s2 +

Notes of caution:

  • Add a manufactures testing uncertainty value (typically plus or minus 1.5m/s2) to the advertised figures when making calculations
  • Figures are quoted for new tools and give little consideration to old equipment, disc or material type as this can significantly vary (e.g. drilling wood or concrete / Hedge cutting laurel or beech / sanding high density or low-density materials)

The HSE has a system in which exposures can be more simply expressed as ‘points’.

Tip: m/s2 x m/s2 x2 = Points per hour. e.g. a tool of 6 m/s2  (6x6x2)= 71 points per hour.

Time

When making calculations it’s important to note that exposure is dictated by time on the ‘trigger’, and not necessarily the ‘activity’ time.  Trigger time is very difficult to estimate so the best way of quantifying exposure is to employ a specialist to carry out vibration exposure measurements. These measurements can then be used to inform your Risk Assessments.  Where use of tools is limited and not core to the work activity, a ‘desktop’ assessment (estimate) may be all an employer need do.

Legal Exposure Limit Values and Action Values:

The daily exposure limit value is 5 m/s2 A(8) – or expressed as 400 HSE Points per day.

This is the figure at which employees should stop work immediately.

The daily exposure action value is 2.5 m/s2 A(8) – or expressed as 100 HSE Points per day;

This is the figure at which the employer must take steps to reduce exposure to as low as is reasonably practicable and introduce particular control measures within this guidance.  

Important note:

There is no ‘safe level’ of exposure and employers must apply the principles of prevention and always manage risks to as ‘low as reasonably practicable’.

Safe Systems of Work

1. Risk Assessment

The HSE recommends the following five steps in undertaking a risk assessment:

  1. Identify the hazards
  2. Assess the risks
  3. Control the risks
  4. Record significant findings
  5. Review the controls

You will need to:

  • Identify your tools and processes
  • Gather vibration data
  • Measure, or estimate the trigger time and calculate the daily exposure (Use the simple HSE Vibration Exposure Calculator, particularly for multiple tool use)

2. Effective Risk Controls

  • Provide Vibration awareness training to employees
  • Issue relevant information (the HSE Leaflet later referred to in this update, SA47 – Vibration within your H&S manual
  • Select equipment of the lowest vibration magnitude
  • Understand potential exposure and plan works to minimise exposures
  • Maintain tools and equipment
  • The single most effective control to deploy is ‘Work / Task rotation’
  • Implement a simple system where vibration exposures can be monitored
  • Ensure employees receive occupational health monitoring

3. Monitoring

The employers find the biggest challenge is implementing a system where employees can track personal vibration exposures (daily points).  Consider technological solutions for higher risk workers such as wearable HAVs devices which provide real-time monitoring and feedback to the employer.

When used properly, these systems can also signal improper use and tool wear which may require maintenance intervention.

One very practical way of monitoring (counting) and controlling personal exposures might be to express points as daily activity tasks: e.g.

  • A scaffolder running fitting nuts with an impact wrench on X number of fittings to reach 100pts
  • A grounds maintenance operative refuelling a strimmer X number of times to reach 100pts
  • A foundry worker fettling X number of foundry castings to reach 100pts
  • Workplace Timers can also be deployed to assist employees monitor vibration exposure,

However, it must be stressed that the duty to monitor and control exposure is on the employer.

4. Importance of Equipment Maintenance

Wear and tear on tools, bearings, blades and accessories can significantly increase vibration magnitudes. Keep all equipment properly maintained.

Consider the most effective methods in reaching the work objective to reduce trigger times.

Simple measures such as ensuring line trimmers on strimmers are present will ensure line lengths (and vibration magnitudes) are not excessively above manufacturers quoted data.

5. Occupational Health

Where vibration hazards and risks exist, employers should implement the following:

  • Pre-selection health screening questionnaires and occupational health assessment
  • Annual Health Screening questionnaires to employees
  • Annual health surveillance appointments with a qualified Occupational Health Practitioner to
    • detect the early onset of any vibration related industrial disease, and
    • to provide assurance of the effectiveness of the safe systems of work in place

6. RIDDOR

Should your Occupational Health Practitioner diagnose., at any time, the onset of HAVs, the employer will need to make an assessment to what extent the ill-health has been caused by work and, where necessary, report all industrial diseases to the Health and Safety Executive (in accordance with RIDDOR 2015).

References:

The Health and Safety at Work Act 1974

Management of Health & Safety at Work Regulations 1999

The Control of Vibration at Work Regulations 2005.

The Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013

INDG296 HSE Hand-arm Vibration (A Guide for Employees)

INDG175 HSE Hand-arm Vibration at Work (A Brief Guide)