HAV Risk Assessment Guide

“The risk depends on both how strongly a tool vibrates and how long it is actually used.”

A hand-arm vibration (HAV) risk assessment identifies which workers are exposed to vibration, estimates their daily exposure and sets out how the risk will be controlled.

For some workplaces, suitable vibration data and a realistic estimate of tool use are enough to make those decisions. Where the available figures do not represent how tools are used on site, professional measurement can provide more reliable evidence.

This guide explains the assessment process, the 100-point and 400-point thresholds, when tool testing helps, and when workers need health surveillance.

Explore Velocity Safety’s hand-arm vibration measurement and assessment service.

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What Is Hand-Arm Vibration?

Hand-arm vibration is vibration transmitted into the hands and arms while using hand-held or hand-guided equipment. It can also pass through a workpiece held against a powered machine.

Examples include breakers, hammer drills, grinders, impact tools, chainsaws, strimmers and vibrating manufacturing processes.

Regular exposure can contribute to hand-arm vibration syndrome (HAVS) and carpal tunnel syndrome. Possible symptoms include tingling, numbness, loss of dexterity and fingers turning white in the cold. Employers should encourage workers to report symptoms promptly so the risks and their exposure can be reviewed.

How Do You Carry Out a HAV Risk Assessment?

The Control of Vibration at Work Regulations 2005 require employers to assess and control vibration risks. A useful assessment follows the actual work rather than relying only on a list of tool specifications.

1. Identify the tools and processes. Record the equipment, accessories, materials and tasks that transmit vibration to workers’ hands.
2. Identify who uses them. Include workers who switch between tools or tasks during the same day.
3. Establish representative vibration magnitudes. Use suitable HSE, supplier or workplace data. Consider measurement where available figures do not represent the work.
4. Establish actual trigger times. Observe how long each worker’s hands are exposed while the tool is operating. Time spent holding an idle tool does not count as trigger time.
5. Estimate daily exposure. Use the HSE calculator or exposure points system to combine the tools and tasks used by each worker.
6. Decide and record what action is needed. Identify controls, workers requiring health surveillance, responsibilities and a timetable for improvements.

The assessment should be based on a reasonable estimate. If workers use several vibrating tools, overlooking one task can understate their total exposure.

How Do HAV Exposure Points Work?

Exposure points express a worker’s daily hand-arm vibration exposure in a way that makes different tools and trigger times easier to combine.

A tool’s vibration magnitude is expressed in metres per second squared (m/s²). Daily exposure is expressed as A(8), an eight-hour equivalent value. Points give another way to present that daily result:

• 100 points per day: the Exposure Action Value.
• 400 points per day: the Exposure Limit Value.

For example, using a tool with a representative vibration magnitude of 5 m/s² for two hours of actual trigger time produces approximately 100 points. If the worker then uses another vibrating tool, its points must be added to the same daily total.

The HSE hand-arm vibration exposure calculator accepts vibration magnitude and exposure duration for multiple tools and calculates both A(8) and exposure points.

What Is the Difference Between the EAV and ELV?

Both values apply to an individual worker’s total daily hand-arm vibration exposure.

Exposure below the EAV does not mean a tool presents no risk under every circumstance. The assessment must still consider how often exposure occurs, the workers involved and any reported symptoms.

When Is On-Site HAV Measurement Needed?

A HAV risk assessment does not automatically require every tool to undergo a measured test. HSE advises that vibration magnitudes need to be measured when suitable data for the assessment cannot be obtained from other sources.

Manufacturer figures are useful for comparing products, but a declared value may not represent the vibration experienced during a particular workplace task. The accessory, material, tool condition, work method and operator can all affect the result.

On-site measurement can be particularly useful when:

• Available data is missing, inconsistent or unlikely to reflect actual tool use.
• Different accessories or materials may change vibration substantially.
• The estimated exposure sits close to an action or limit value.
• The employer needs better evidence to compare tools or assess whether controls work.
• Workers report symptoms or unexpectedly high vibration.

Velocity Safety measures tools and processes in use to support workplace HAV assessments.

What happens during professional HAV measurement?

A competent assessor gathers details of the tool, task and operating conditions, then uses suitable calibrated vibration measurement equipment while representative work is carried out.

The vibration transducer is mounted appropriately near where vibration enters the hand. The resulting vibration magnitude is considered alongside realistic trigger-time information to estimate exposure for the workers and tasks involved.

A useful report should identify what was measured, the operating conditions, the results and the assumptions used in any exposure calculations. The employer can then use the findings to update its assessment and control plan.

HAV Tool Timers vs Vibration Measurement: What Is the Difference?

A tool timer, logbook or electronic monitoring system can help estimate how long equipment is used. Professional vibration measurement establishes a representative vibration magnitude for a tool and task.

Some monitoring systems combine recorded time with an entered vibration value to estimate points. Their result depends on whether that value represents the actual work. A wrist-worn timer should not be treated as a direct measurement of vibration transmitted into the worker’s hand.

HSE also cautions that continuous monitoring alone does not control the risk. Employers still need suitable work methods, equipment and exposure controls.

How Can Employers Reduce HAV Exposure?

The assessment should lead to practical changes. Depending on the task, these may include:

• Changing the method: Mechanise a task or use a process that removes the need for a hand-held vibrating tool.
• Choosing suitable equipment: Select a lower-vibration tool that can complete the job efficiently. A tool that takes much longer can increase total exposure.
• Maintaining equipment and accessories: Replace worn bits, blunt chisels and damaged grinding consumables; follow the manufacturer’s maintenance instructions.
• Planning the work: Reduce unnecessary trigger time and distribute tasks so one worker does not receive excessive daily exposure.
• Training workers: Explain tool selection, correct use, symptoms and how to report problems.

Gloves may help keep hands warm, but they should not be relied upon as the main means of reducing vibration exposure.

When Is HAVS Health Surveillance Required?

HAVS health surveillance checks workers for early signs of vibration-related ill health. It is separate from measuring a tool or calculating daily exposure.

HSE says employers must provide health surveillance for workers who, despite controls, are likely to be regularly exposed above the EAV, or who are considered at risk for another reason.

An appropriate programme may start with regular symptom questionnaires and refer positive responses for occupational health assessment. Employers should act on advice about continued exposure and use the findings to review their risk assessment and controls.

A tool measurement report can help identify who may need surveillance. It does not replace the surveillance itself.

How Often Should a HAV Risk Assessment Be Reviewed?

Review the assessment when changes could affect exposure, including:

• New tools, accessories, materials or work methods.
• Changes in how often or how long workers use equipment.
• Equipment wear, poor maintenance or unexpected vibration.
• Reported symptoms or findings from health surveillance.
• Evidence that existing controls are not working.

Review it regularly even when work appears stable. HSE advises that employers should not leave it for more than about two years without checking whether a review is needed.

There is no universal rule requiring every tool to be professionally measured once a year. Repeat measurement when it is needed to keep the exposure estimate representative or to verify a change in controls.

Final Takeaway

An effective HAV risk assessment connects the work people actually do with representative vibration data and realistic trigger times. It adds exposure from different tools across the day, identifies who is approaching the EAV or ELV and leads to controls that reduce the risk.

Where existing vibration figures cannot support a reliable assessment, on-site measurement helps replace assumptions with evidence.

Frequently Asked Questions

Is a hand-arm vibration risk assessment a legal requirement?

Employers must assess the risk to workers exposed to vibration under the Control of Vibration at Work Regulations 2005. The findings should identify exposure, necessary controls and any workers who need health surveillance.

Does every vibrating tool have to be measured?

No. An assessment can use suitable representative data from HSE, suppliers or other reliable sources. Professional measurement is needed when suitable vibration data cannot be obtained another way.

What is trigger time?

Trigger time is the time a worker’s hands are exposed to vibration while the equipment is operating. It can be much shorter than the total time spent on a job or holding the tool.

What do 100 HAV exposure points mean?

One hundred points is equivalent to the daily Exposure Action Value of 2.5 m/s² A(8). Reaching this level triggers a planned programme of measures to reduce vibration exposure.

What do 400 HAV exposure points mean?

Four hundred points is equivalent to the daily Exposure Limit Value of 5.0 m/s² A(8). It is a limit that must not be exceeded, rather than a target for normal working.

How do you account for several tools used in one day?

Estimate the exposure contribution of each tool or task from its representative vibration magnitude and trigger time. Add the exposure points to establish that worker’s daily total.

Can a HAV timer measure tool vibration?

A timer records or estimates use duration. It does not, by itself, measure the vibration magnitude transmitted into the hands. Any exposure calculation using timer data also needs a suitable vibration value.

When is HAVS health surveillance needed?

Provide it where workers are regularly likely to be exposed above the EAV despite controls, or are otherwise considered at risk. It checks for signs of ill health and is separate from tool testing.

How often should HAV testing be repeated?

There is no universal annual tool-testing interval. Review the assessment when work or exposure changes and regularly thereafter; repeat professional measurement when the existing data is no longer representative or better evidence is needed.

Resources

• • HSE – Vibration Risk Assessment
  • HSE – Control of Vibration at Work Regulations 2005
  • HSE – Hand-Arm Vibration Exposure Calculator
  • HSE – Measurement and Monitoring Guidance
  • HSE – Protecting Workers and Providing Health Surveillance