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Measuring Hand Arm Vibration Syndrome (HAVs)

Measuring Hand Arm Vibration Syndrome (HAVs)

Introduction

Hand arm vibration (HAV) is the vibration transmitted from work processes into workers’ hands and arms.

It can be caused by operating hand-held power tools, such as road breakers, or hand-guided equipment, such as powered lawnmowers, or by holding materials being processed by machines, such as pedestal grinders.

HAV is a serious health and safety issue that affects millions of workers around the world. Exposure to HAV can cause various disorders and injuries to the fingers, hands, and arms, collectively known as hand-arm vibration syndrome (HAVS).

Some of the symptoms of HAVS include numbness, tingling, pain, and reduced grip strength in the fingers and hands. HAVS can also affect the blood vessels, nerves, muscles, and joints of the arms and shoulders. In some cases, HAVS can be permanent and disabling, affecting the quality of life and work performance of affected workers.

The main purpose of this blog is to provide some guidelines for measuring HAV exposure and complying with the Control of Vibration at Work Regulations 2005.

These regulations aim to protect workers from the risks of HAV by setting legal limits for exposure and requiring employers to take actions to prevent or control exposure.

Measuring HAV exposure is essential for assessing the level of risk and determining the appropriate control measures.

However, measuring HAV exposure can be challenging, as it depends on various factors, such as the type and condition of the tool or equipment, the duration and frequency of use, the way the worker holds or operates the tool or equipment, and the characteristics of the work or material.

Therefore, this blog will explain some of the methods and tools that can help employers and workers measure HAV exposure accurately and effectively.

Man breaking up concrete with road breaker

History of HAVS

According to the web search results, the history of hand-arm vibration syndrome (HAVS) dates back to the early 20th century, when it was first recognised as an occupational disease among workers who used pneumatic hammers and drills.

The term “vibration white finger” was coined in 1911 by Loriga, who described the blanching and numbness of the fingers in Italian quarry workers.

The condition was also observed in other countries, such as Japan, Germany, and the UK, where it was known as “dead finger”, “Raynaud’s phenomenon of occupational origin”, or “occupational acroparaesthesia” respectively.

In 1975, the International Labour Organization (ILO) adopted a resolution to classify HAVS as an occupational disease and to establish diagnostic criteria and compensation schemes.

The term “hand-arm vibration syndrome” was introduced in 1986 by the Stockholm Workshop on Vibration-Induced Disorders, which recognised that HAVS can affect not only the vascular system, but also the sensory and musculoskeletal systems of the hand and arm.

Since then, HAVS has been widely accepted as a generic term for the various disorders caused by exposure to hand-transmitted vibration.

How is HAVS Diagnosed?

HAVS is diagnosed based on the symptoms and exposure history of the worker, as well as a physical examination and some tests.

The symptoms of HAVS are classified into three stages: vascular (affecting the blood circulation), sensory (affecting the sensation) and musculoskeletal (affecting the muscles and bones).

The stages are further divided into early and late sub-stages, depending on the severity and frequency of the symptoms. The diagnosis of HAVS is confirmed by the presence of IgM antibody to HAV in the blood, which indicates an acute infection.

There is no specific treatment for HAVS, but the condition can be prevented or improved by stopping or reducing exposure to vibration.

Vibration Magnitude & Exposure Duration

One of the key factors that determines the level of HAV exposure is the vibration magnitude of the tool or equipment. The vibration magnitude is a measure of the intensity of the vibration, usually expressed in metres per second squared (m/s²).

The higher the vibration magnitude, the higher the risk of HAVS. Another factor that affects the HAV exposure is the exposure duration, which is the total time that the worker is exposed to the vibration in a day. The longer the exposure duration, the higher the risk of HAVS.

To assess the risk of HAV exposure, it is important to compare the vibration magnitude and exposure duration with the legal thresholds set by the Control of Vibration at Work Regulations 2005.

These thresholds are called the exposure action value (EAV) and the exposure limit value (ELV). The EAV is 2.5 m/s² and the ELV is 5 m/s².

These values represent the daily vibration exposure that a worker can be exposed to without significant risk of injury.

If the vibration exposure exceeds the EAV, then employers must take actions to reduce it. If the vibration exposure exceeds the ELV, then employers must take immediate actions to prevent further exposure.

If measuring EAV and ELV seems quite complicated to you, you wouldn't be the first to think so. In fact, it's one of the reasons spacebands developed a HAV monitoring feature into our workplace wearable. It allows employers to set threshold levels they are comfortable with (out of the box spacebands' devices are set to HSE regulations), and allow workers and employers to get on with their jobs without having to worry about complicated calculations.

Man operating pedestal grinder

Measuring Vibration Magnitude and Exposure Duration

To measure vibration magnitude and exposure duration, there are several methods that can be used, such as using a vibration meter, consulting manufacturer’s data, or using online tools like the HSE vibration calculator.

Each method has its own advantages and disadvantages, and some tips for choosing the most suitable one for different situations are given below.

  • Using a vibration meter: A vibration meter is a device that can measure the vibration magnitude of a tool or equipment directly. It can be attached to the tool or equipment, or to the worker’s hand or arm, depending on the type of meter.
    The advantage of using a vibration meter is that it can provide accurate and reliable measurements of the actual vibration magnitude in different conditions and scenarios.
    The disadvantage of using a vibration meter is that it can be costly, time-consuming, and impractical to use for every tool or equipment and every worker.
    Therefore, using a vibration meter is recommended when there is no reliable manufacturer’s data available, or when there is a significant variation in the vibration magnitude due to factors such as tool wear, maintenance, or operator technique.
  • Consulting manufacturer’s data: Manufacturer’s data is the information provided by the manufacturer of the tool or equipment about its vibration magnitude. It can be found in the product manual, label, or website.
    The advantage of consulting manufacturer’s data is that it can provide a quick and easy way to estimate the vibration magnitude without using any device.
    The disadvantage of consulting manufacturer’s data is that it may not reflect the actual vibration magnitude in real work situations, as it may be based on laboratory tests or ideal conditions.
    Therefore, consulting manufacturer’s data is recommended when there is no vibration meter available, or when the manufacturer’s data is verified by independent tests or measurements.
  • Using online tools: Online tools are web-based applications that can help estimate the vibration magnitude and exposure duration based on user input.
    One example of an online tool is the HSE vibration calculator, which is developed by the Health and Safety Executive (HSE) in the UK.
    The advantage of using online tools is that they can provide a convenient and accessible way to calculate HAV exposure without requiring any device or data.
    The disadvantage of using online tools is that they may not account for all the factors that affect HAV exposure, such as tool condition, workpiece material, or operator skill.
    Therefore, using online tools is recommended when there is no other method available, or when the online tool is validated by other sources or measurements.

How to Use the Exposure Points System

The exposure points system and the ready-reckoner table are tools that can help estimate HAV exposure from multiple sources or tasks.

The exposure points system is a way of expressing HAV exposure in terms of points, where 100 points is equivalent to the EAV of 2.5 m/s² and 400 points is equivalent to the ELV of 5 m/s².

The ready-reckoner table is a table that shows the number of points for different combinations of vibration magnitude and exposure duration. To use these tools, follow these steps:

  • Identify all the sources or tasks that contribute to HAV exposure in a day.
  • For each source or task, find out the vibration magnitude and exposure duration, using any of the methods described in the previous section.
  • For each source or task, use the ready-reckoner table to find the number of points corresponding to the vibration magnitude and exposure duration.
  • Add up all the points from all the sources or tasks to get the total daily exposure points.
  • Compare the total daily exposure points with the EAV and ELV thresholds to assess the risk level and determine the appropriate control measures.

Here are some examples of what that might look like in an actual business case:

Example 1:

A carpenter uses a circular saw, a hammer drill, and a sander for different tasks in a day. The manufacturer’s data for these tools are as follows: circular saw: 4 m/s², hammer drill: 15 m/s², sander: 2.5 m/s². The carpenter uses each tool for 30 minutes in a day. To calculate HAV exposure, follow these steps:

  • For each tool, use the manufacturer’s data to find out the vibration magnitude.
  • For each tool, use the actual usage time to find out the exposure duration.
  • For each tool, use the ready-reckoner table to find out the number of points. For example, for the circular saw, look for the row with 4 m/s² and the column with 30 minutes, and find that it has 100 points.
  • Add up all the points from all the tools to get the total daily exposure points. In this case, it is 100 + 600 + 50 = 750 points.
  • Compare the total daily exposure points with the EAV and ELV thresholds. In this case, it exceeds both thresholds, which means that HAV exposure is very high and immediate actions are needed to prevent further exposure.

Example 2:

A gardener uses a hedge trimmer, a leaf blower, and a lawn mower for different tasks in a day. The gardener does not have any manufacturer’s data or vibration meter for these tools, so he uses an online tool like the HSE vibration calculator to estimate the vibration magnitude and exposure duration.

The online tool gives him these results: hedge trimmer: 5 m/s², 15 minutes; leaf blower: 3 m/s², 45 minutes; lawn mower: 2 m/s², 60 minutes. To calculate HAV exposure, follow these steps:

  • For each tool, use the online tool results to find out the vibration magnitude and exposure duration.
  • For each tool, use the ready-reckoner table to find out the number of points. For example, for the hedge trimmer, look for the row with 5 m/s² and the column with 15 minutes, and find that it has 150 points.
  • Add up all the points from all the tools to get the total daily exposure points. In this case, it is 150 + 90 + 40 = 280 points.
  • Compare the total daily exposure points with the EAV and ELV thresholds. In this case, it exceeds only the EAV threshold, which means that HAV exposure is moderate and actions are needed to reduce it.

Man operating powered lawnmower

How Can I Reduce HAV Exposure?

Some actions that employers and workers can take to reduce HAV exposure are:

  • Alternative work methods: Look for alternative work methods that eliminate or reduce exposure to vibration, such as mechanising or automating the work, or using different types of tools or equipment that do not require vibration.
  • Equipment selection: Choose the lowest vibration tool that is suitable and can do the work efficiently, and limit the use of high-vibration tools wherever possible. Replace old equipment and tools with newer and lower vibration models, and consult with suppliers and industry contacts to find out the best options.
  • Maintenance and repair: Keep the tools and equipment in good condition and repair any faults or damages that may increase vibration. Follow the manufacturer’s instructions for maintenance and servicing, and use the correct accessories and consumables for the tools and equipment.
  • Work organisation: Plan and organise the work to reduce exposure time and allow recovery time for workers. Rotate workers between different tasks to avoid prolonged or continuous exposure to vibration, and schedule regular breaks from vibrating tools or equipment.
  • Training and information: Provide training and information to workers on how to use the tools and equipment safely and efficiently, and how to recognise and report signs and symptoms of HAVS. Raise awareness of the risks of HAV exposure and the benefits of control measures among workers and managers.
  • Personal protective equipment: Provide anti-vibration gloves to workers who use vibrating tools or equipment, and ensure that they fit properly and are comfortable to wear. However, note that anti-vibration gloves do not eliminate the risk of HAVS, and may reduce the grip or dexterity of the worker, so they should not be relied on as the sole or primary control measure.
  • Health surveillance: Monitor the health of workers who are exposed to HAV, and provide them with regular health checks and medical examinations. Identify any workers who have or may develop HAVS, and take appropriate actions to prevent further harm, such as adjusting their work or referring them to a specialist

How Can I Protect My Company from HAVS Claims?

HAVS claims are compensation claims made by workers who may or may not have developed HAVS as a result of their work.

At spacebands we regularly speak with companies that have had to pay out on fraudulent HAVS claims because even if an employee hasn't been over-exposed to hand-arm vibration, it's hard to prove in a court of law.

spacebands' HAV feature records information on HAV exposure and saves the information to an analytics dashboard, giving companies a record of exposure, or lack thereof, to protect themselves against fraudulent claims.

These claims can be costly and damaging for employers, as they may have to pay for medical expenses, loss of earnings, pain and suffering, and legal fees.

Moreover, HAVS claims can also harm the reputation and productivity of the company, as they may indicate a lack of care and responsibility for worker health and safety.

To avoid or minimise the risk of HAVS claims, employers should follow the guidelines provided by the Health and Safety Executive (HSE), which is the authority responsible for enforcing the Control of Vibration at Work Regulations 2005. Some of the key guidelines are:

  • Carry out regular risk assessments to identify the sources and levels of HAV exposure in the workplace, and review them whenever there are changes in work processes, tools, or equipment.
  • Choose the lowest vibration tools that are suitable and can do the work efficiently, and limit the use of high-vibration tools wherever possible. Replace old tools and equipment with newer and lower vibration models, and consult with suppliers and industry contacts to find out the best options.
  • Keep the tools and equipment in good condition and repair any faults or damages that may increase vibration. Follow the manufacturer’s instructions for maintenance and servicing, and use the correct accessories and consumables for the tools and equipment.
  • Plan and organise the work to reduce exposure time and allow recovery time for workers. Rotate workers between different tasks to avoid prolonged or continuous exposure to vibration, and schedule regular breaks from vibrating tools or equipment.
  • Provide training and information to workers on how to use the tools and equipment safely and efficiently, and how to recognise and report signs and symptoms of HAVS. Raise awareness of the risks of HAV exposure and the benefits of control measures among workers and managers.
  • Provide anti-vibration gloves to workers who use vibrating tools or equipment, and ensure that they fit properly and are comfortable to wear. However, note that anti-vibration gloves do not eliminate the risk of HAVS, and may reduce the grip or dexterity of the worker, so they should not be relied on as the sole or primary control measure.
  • Monitor the health of workers who are exposed to HAV, and provide them with regular health checks and medical examinations. Identify any workers who have or may develop HAVS, and take appropriate actions to prevent further harm, such as adjusting their work or referring them to a specialist.
  • Keep records of exposure and health surveillance for at least 40 years, as HAVS may develop or worsen over time. These records can help employers track the effectiveness of control measures, identify any trends or patterns in exposure or health outcomes, and provide evidence in case of any claims or disputes.

By following these guidelines, employers can protect their company from HAVS claims by demonstrating that they have taken reasonable steps to prevent or control HAV exposure in accordance with the law.

However, if a worker does make a claim for HAVS compensation against their employer, it is advisable for employers to seek legal advice from a solicitor who specialises in industrial disease claims.

A solicitor can help employers understand their rights and obligations under the law, assess the validity and value of the claim, negotiate a settlement or defend a court case if necessary.

A solicitor can also help employers avoid making any mistakes or admissions that could jeopardise their position or increase their liability.

Man operating industrial grinder

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