How to Do a HAVs Assessment: Hand-Arm Vibration Guide for UK Construction

If your workers use vibrating tools, you have a legal duty to assess their exposure to hand-arm vibration. Get it wrong, and people develop Hand-Arm Vibration Syndrome (HAVS), a painful, irreversible condition that destroys blood vessels, nerves, and joints in the hands and arms. Over 2 million UK workers are at risk.

This guide walks you through the full HAVs assessment process: understanding the legal limits, calculating exposure using the HSE points system, writing the assessment, and putting controls in place that actually reduce the risk.

What Is HAVS?

Hand-Arm Vibration Syndrome is a group of conditions caused by regular, prolonged use of vibrating hand-held tools. It affects three systems in the hands and arms:

• Blood vessels (vascular) : fingers turn white and lose feeling, known as vibration white finger (VWF). Attacks are triggered by cold and can last hours.
• Nerves (neurological): permanent tingling, numbness, and loss of sensation. Workers struggle to pick up small objects or feel temperature changes.
• Muscles and joints (musculoskeletal): reduced grip strength, pain in wrists and forearms, difficulty with everyday tasks.

The critical thing to understand: HAVS is irreversible. Once symptoms appear, the damage is permanent. There is no cure, no surgery, no medication that reverses it. The only option is to prevent further deterioration by reducing or eliminating exposure. That is why the assessment matters so much.

The Legal Limits

The Control of Vibration at Work Regulations 2005 set two daily exposure limits, both based on an 8-hour reference period (written as A(8)):

• Exposure Action Value (EAV): 2.5 m/s² A(8). When exposure reaches this level, you must take action to reduce it. This means introducing controls, providing health surveillance, and informing workers of the risks.
• Exposure Limit Value (ELV): 5 m/s² A(8). This must not be exceeded under any circumstances. If a worker's daily exposure hits this level, you must stop the work and reorganise it immediately.

These are daily limits. A worker who uses an angle grinder for 30 minutes in the morning and a breaker for 20 minutes in the afternoon has a combined daily exposure. You need to account for every vibrating tool they use across the full shift.

How to Calculate Exposure

The HSE provides an exposure points system that simplifies the maths. Instead of working with the A(8) formula directly, you convert vibration magnitude and trigger time into points:

• 100 points = EAV (equivalent to 2.5 m/s² A(8))
• 400 points = ELV (equivalent to 5 m/s² A(8))

The formula is straightforward: exposure points = vibration magnitude² × time in hours. So a tool with a magnitude of 5 m/s² used for 2 hours gives you 5² × 2 = 50 points.

Worked Example

A worker uses an angle grinder with a vibration magnitude of 8 m/s² for 1 hour of actual trigger time:

Exposure points = 8² × 1 = 64 × 1 = 64 points per hour. But wait, the HSE points system uses a slightly different scale. Using the HSE ready reckoner: 8 m/s² for 1 hour = 256 points. That is already well above the EAV (100 points) and close to the ELV (400 points).

If the same worker then uses a hammer drill at 12 m/s² for 30 minutes, that adds another 288 points. The total daily exposure would be 544 points, which exceeds the ELV. This work pattern must be changed.

You can use the HSE's online exposure calculator or the ready reckoner table to look up points for different magnitude/time combinations. For most site assessments, the ready reckoner is the fastest approach.

Common Tool Vibration Magnitudes

Here are typical vibration magnitudes for common construction tools. These are real-world values, which are often higher than manufacturer data sheets suggest:

• Breaker / demolition hammer: 12–25 m/s². These are the highest-risk tools on site. Even 15 minutes of trigger time on a large breaker can push a worker above the EAV.
• Angle grinder: 4–10 m/s². Varies significantly by disc size, condition, and material being cut.
• Hammer drill: 6–20 m/s². Rotary hammer drills at the higher end, standard hammer drills at the lower end.
• Needle scaler: 5–15 m/s². Often used for long periods, making them a significant HAVS risk despite moderate magnitudes.
• Disc cutter: 4–8 m/s². Concrete cutting generates higher vibration than asphalt.
• Jigsaw: 5–12 m/s². Blade condition and material hardness have a big impact.

Always check the manufacturer's vibration data for the specific tool model. Be aware that declared values are tested under controlled conditions. Real-world vibration is typically higher, sometimes significantly so. The HSE recommends multiplying manufacturer data by a factor of 1.5 to 2 for a more realistic estimate.

Writing the Assessment

A HAVs assessment follows a clear step-by-step process. Here is how to work through it:

Step 1: Identify All Vibrating Tools

List every vibrating tool used on site or in the workshop. Include tools that might only be used occasionally. Talk to workers, they often use tools that supervisors are not aware of.

Step 2: Get Vibration Magnitudes

For each tool, find the vibration magnitude in m/s². You have three sources: the manufacturer's declaration (check the manual or their website), the HSE's vibration database (covers hundreds of tool models), or direct measurement with a vibration meter. Manufacturer data is the easiest to obtain but often underestimates real exposure.

Step 3: Calculate Daily Exposure

For each worker (or worker group doing the same tasks), calculate the daily exposure. Use actual trigger time, not the total time the tool is available. A worker might have an angle grinder plugged in for 4 hours but only actively cutting for 45 minutes. It is the 45 minutes that counts.

Step 4: Compare Against EAV and ELV

Add up the exposure points from all tools used during the shift. Compare the total against 100 points (EAV) and 400 points (ELV). If you are below 100 points, exposure is low risk but you should still look for ways to reduce it. Between 100 and 400 points, you must take action. Above 400 points, the work must stop and be reorganised.

Step 5: Implement Controls

Put measures in place to reduce exposure. This is where many assessments fall short. Generic statements like 'use PPE' are not enough. You need specific, practical controls: which low-vibration tool models to purchase, how to rotate workers, maximum trigger times per tool, break schedules. More on effective controls below.

Step 6: Record and Review

Document everything. Record the tools assessed, vibration magnitudes used, trigger times assumed, exposure calculations, and the controls you have put in place. Review the assessment whenever tools change, work patterns change, or health surveillance results suggest exposure levels are not controlled.

Health Surveillance

Health surveillance is a legal requirement when workers are regularly exposed at or above the EAV. It is your early warning system. The purpose is to detect HAVS symptoms before they become severe, so you can intervene and protect the worker from further damage.

The surveillance follows a tiered system:

• Tier 1: Initial screening questionnaire. Completed before the worker starts vibration work, then annually. Asks about symptoms such as tingling, numbness, and white finger attacks.
• Tier 2: Clinical assessment. Carried out by a trained occupational health nurse if the questionnaire flags any concerns. Includes standardised tests for grip strength, dexterity, and sensory perception.
• Tier 3/4/5: Formal diagnosis. Referral to a doctor or specialist for confirmed diagnosis and staging of the condition. Includes vascular (cold provocation) and neurological testing.

Surveillance must be repeated annually. You must act on the results. If a worker is diagnosed with HAVS, you need to reduce their exposure further or, in serious cases, redeploy them to work that does not involve vibrating tools. Ignoring health surveillance results is not an option and could lead to enforcement action.

Control Measures That Actually Reduce Exposure

Not all control measures are equal. Here are the ones that make a real difference, in order of effectiveness:

1. Buy low-vibration tools. This is the single biggest impact you can make. A low-vibration breaker at 8 m/s² instead of 20 m/s² reduces exposure points by more than 80%. When replacing tools, always compare vibration declarations and choose the lowest available.
2. Maintain tools properly. Worn, blunt, or damaged tools vibrate more than well-maintained ones. Blunt chisels, worn bearings, and loose fixings all increase vibration magnitude. A simple maintenance schedule can significantly reduce exposure.
3. Job rotation. Limit individual trigger time by rotating workers between vibrating and non-vibrating tasks. This spreads the exposure across more people, keeping everyone below the limits. Plan work schedules so nobody is using high-vibration tools all day.
4. Keep hands warm. Cold constricts blood vessels and worsens vibration damage. Provide warm welfare facilities, encourage warm gloves between tasks, and avoid using vibrating tools first thing on a cold morning when hands are at their coldest.
5. Regular breaks. Take a break from vibrating tools every 15 to 20 minutes. This allows blood flow to recover and reduces cumulative damage. Short, frequent breaks are more effective than one long break.
6. Anti-vibration gloves. These provide only marginal benefit. They can reduce high-frequency vibration slightly, but they do not significantly reduce the lower frequencies that cause the most damage. Do not rely on anti-vibration gloves as your primary control measure. They are a supplement, not a solution.

Generate Your HAVs Assessment with SwiftRMS

Calculating vibration exposure manually is time-consuming, especially when you have multiple tools, varying trigger times, and workers rotating between tasks. SwiftRMS generates HAVs assessments with tool-specific vibration data and automatic exposure calculations, so you can produce compliant documentation in minutes instead of hours.

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Related Guides

If you found this guide useful, you may also want to read:

• Manual Handling Assessment Guide . Another common assessment that construction teams need to get right. Covers the TILE framework and practical lifting assessments.
• What Is a RAMS Document? . If you are writing risk assessments and method statements, this guide explains the full RAMS process and what to include.
• COSHH Assessment for Silica Dust . Workers cutting concrete and stone face both HAVS and silica dust exposure. This guide covers the COSHH side of that equation.