Hand Arm Vibration Exposure Limits: EAV and ELV Quick Reference
The Two HAVS Thresholds Every UK Employer Must Know
The Control of Vibration at Work Regulations 2005 set two daily exposure limits for hand-arm vibration:
| Threshold | A(8) value | Exposure points | What it means |
|---|---|---|---|
| EAV (Exposure Action Value) | 2.5 m/s² | 100 points | Employer must take action to reduce exposure |
| ELV (Exposure Limit Value) | 5 m/s² | 400 points | Legal maximum — must not be exceeded |
Both are expressed as A(8) — the daily vibration exposure normalised to an 8-hour reference period. The exposure points system (100 for EAV, 400 for ELV) is mathematically equivalent and easier to use when workers use multiple tools.
What A(8) Actually Means
A(8) is not the raw vibration measurement from the tool. It's the combined effect of vibration magnitude and exposure duration, normalised to 8 hours.
A tool rated at 5 m/s² used for 8 hours produces A(8) = 5 m/s² (exactly the ELV). The same tool used for 2 hours produces A(8) = 2.5 m/s² (exactly the EAV). Use it for 30 minutes and A(8) = 1.25 m/s² (below EAV).
The formula: A(8) = vibration magnitude × √(trigger time ÷ 8 hours)
The exposure points formula is simpler for on-site use:
Points per hour = (magnitude ÷ 2.5)² × 100
Total daily points = sum of (points per hour × hours) for each tool. Compare against 100 (EAV) and 400 (ELV).
Use the free HAVS Exposure Calculator to run these calculations without the maths.
What You Must Do at the EAV (100 Points)
When any worker's daily exposure reaches 100 points (2.5 m/s² A(8)):
- Introduce a programme of controls to reduce exposure — tool rotation, job rotation, substituting lower-vibration equipment, limiting trigger times
- Provide health surveillance — Tier 1-3 screening for exposed workers
- Provide information and training — workers must understand the risks of HAVS and how to reduce exposure
- Review your risk assessment — update it to reflect the exposure levels you're seeing
The EAV is not a safe level. It's the point where the regulations require you to actively manage the risk. Below the EAV, you still have a general duty to reduce exposure as far as reasonably practicable.
What You Must Do at the ELV (400 Points)
The ELV is a hard legal limit. If a worker's exposure reaches 400 points (5 m/s² A(8)):
- Stop the worker using vibrating tools immediately for the rest of the shift
- Investigate the cause — was trigger time underestimated? Was the wrong tool used? Did multi-tool exposure compound?
- Update your risk assessment and controls to prevent recurrence
- Refer the worker for health surveillance if not already enrolled
Exceeding the ELV is a breach of the regulations. HSE enforcement can result in improvement notices, prohibition notices, and prosecution. Fines for health and safety offences are unlimited in the Crown Court.
Common EAV/ELV Trigger Times
How long before common tools hit each threshold:
| Tool | Typical magnitude | Time to EAV | Time to ELV |
|---|---|---|---|
| Angle grinder (4.5") | 5 m/s² | 4h | 16h |
| Breaker (pneumatic) | 18 m/s² | 1m | 5m |
| Plate compactor | 13 m/s² | 2m | 9m |
| Hammer drill (SDS) | 13 m/s² | 2m | 9m |
| Cut-off saw | 7 m/s² | 1h 2m | 4h 8m |
| Strimmer | 5 m/s² | 4h | 16h |
For a full interactive lookup, see the HAVS Trigger Time Chart.
Multi-Tool Exposure: How Points Stack
The biggest real-world risk isn't a single high-vibration tool — it's the combination of several tools across a shift.
Example: A worker uses a cut-off saw (7 m/s²) for 20 minutes and then a hammer drill (13 m/s²) for 15 minutes.
- Cut-off saw: 784 pts/hr × 0.33 hr = 261 points
- Hammer drill: 2,704 pts/hr × 0.25 hr = 676 points
- Total: 937 points — over twice the ELV from just 35 minutes of combined use
This is why daily tracking matters. Individual tools might look safe for their typical use times, but the daily total is what the regulations care about.
EAV vs. ELV: The Practical Difference
The EAV (100 points) is your trigger for proactive management — introduce controls, start surveillance, train your team. You can continue working at or above the EAV as long as you're actively managing the risk.
The ELV (400 points) is the line you cannot cross. Once you do, the worker must stop and you must investigate. There is no "we'll deal with it tomorrow."
Most small contractor enforcement cases involve repeated ELV breaches without records showing any attempt to manage exposure. The records don't have to be perfect — they have to exist.
Summary
| EAV | ELV | |
|---|---|---|
| Level | 2.5 m/s² A(8) / 100 points | 5 m/s² A(8) / 400 points |
| Meaning | Action level — must manage risk | Legal limit — must not exceed |
| Duties | Controls, surveillance, training, risk assessment review | Stop exposure immediately, investigate, prevent recurrence |
| Enforcement | Improvement notice if no controls in place | Prosecution possible for repeated or negligent breaches |
Sources
This guide is for general information only. It is not a substitute for professional health and safety advice.