Phoenix Journal · LEV Testing
Hand-arm vibration syndrome is a slow, permanent injury that creeps up on anyone who works with vibrating tools. Here is how it develops, the numbers that trigger action, and how to keep your crews well below them.
Occupational health
Hand-arm vibration syndrome is one of the quietest injuries in the trades - no bang, no fall, just a slow loss of feeling in the hands that, by the time you notice it, usually cannot be undone.
If your work involves rotary duct-cleaning brushes, needle guns, drills, angle grinders or powered access-panel cutters, vibration is passing into your hands every time you pull the trigger. Most of the time it feels like nothing. That is exactly the problem. Hand-arm vibration syndrome - HAVS for short - builds up so gradually that many people put the early signs down to cold weather or getting older, and only take them seriously once the damage is permanent.
This guide sets out what vibration actually does to the hand, the exposure figures that carry legal weight in the UK, and the practical steps that keep a cleaning or extraction crew working safely for a full career rather than cutting it short. It is written for the people holding the tools and the people who plan their days.
HAVS is not a single condition. It is an umbrella term for the damage that repeated vibration causes to the blood vessels, nerves, muscles and joints of the hand and forearm. The three strands often appear together, and each one progresses on its own timeline.
The vascular strand is the one most people have heard of, usually by its older name: vibration white finger. Small blood vessels in the fingers over-react and clamp shut, so the fingertips blanch white, go numb, then flush red and painful as the blood returns. Cold and wet conditions trigger an attack, which makes an early-morning outdoor call-out or a walk-in chiller a reliable test of whether something is wrong. Left unchecked, the blanching spreads down the fingers and the attacks come more often.
The sensorineural strand attacks the nerves. It shows up as tingling and numbness that lingers after the tool is put down, then as a loss of fine touch and grip - fiddly work like re-fitting fixings, handling small clips or feeling for a hidden fault becomes clumsy and slow. Vibration is also a recognised cause of carpal tunnel syndrome, where the median nerve is compressed at the wrist. The musculoskeletal strand brings aching joints, reduced grip strength and weakness that make a full day of overhead ductwork genuinely harder.
Clinicians in the UK stage HAVS using the Stockholm Workshop Scale, which grades the vascular and sensorineural effects separately from mild through to severe. You do not need the scale to spot trouble early. Tingling in the fingers during or after work, fingertips that go white in the cold, patchy numbness, or a grip that is not what it was are all reasons to raise it with an occupational health provider now rather than next year. The blunt truth is that once the nerve and blood-vessel damage is established it does not reverse - so the whole game is prevention and catching changes early. HAVS remains, as many crews learn the hard way, the slow injury sites ignore until it is too late to fix.
The figures that carry legal weight
Vibration at work is governed in Great Britain by the Control of Vibration at Work Regulations 2005, enforced by the Health and Safety Executive. The regulations set two daily exposure figures for hand-arm vibration, both expressed as an A(8) - an average level spread across an eight-hour working day - and both measured in metres per second squared.
The points system is the practical way most people work with these figures. Every tool has a vibration magnitude, and the longer you hold the trigger the more points you accumulate. Reaching 100 points in a day puts you at the exposure action value; 400 points puts you at the limit. Because a high-vibration tool racks up points fast, some kit can take you past the action value in well under an hour of actual trigger time - far less than most people assume. The HSE publishes a free calculator so you can work this out per tool and per person rather than guessing.
Above the action value you are legally required to reduce exposure so far as is reasonably practicable and to place those workers under health surveillance. The limit value is not a target to aim just below - it is a wall. And a confirmed diagnosis of HAVS or carpal tunnel syndrome linked to the work is reportable to the HSE under RIDDOR, so getting this wrong shows up on the record.
Controlling HAVS is rarely about one dramatic measure. It is a stack of small, unglamorous decisions that together keep daily points low. The most effective by far is choosing tools with a genuinely lower vibration magnitude and keeping them in good order - a worn bearing, a blunt cutter or a poorly balanced rotary brush all push vibration up and drag the job out, which is a double hit on your points total. Buy on measured vibration data, not marketing claims, and service the fleet on a schedule.
From there the levers are about time and technique. Rotate high-vibration tasks around the team so no one person soaks up the whole day's exposure. Plan trigger-time limits into the job so a duct clean or descale is not one operative on the brush for hours. Let the tool do the work with a light grip rather than forcing it, since a tight grip transmits more vibration into the hand. And keep hands warm and dry - good circulation is protective, and cold hands both feel worse and are thought to be more vulnerable, so warm gloves and a warm break matter more than they look.
Where people are regularly exposed at or above the action value, or have a condition such as Raynaud's that makes them more susceptible, health surveillance is not optional. In the UK this runs through a tiered system: a short baseline questionnaire on starting (Tier 1), an annual screening questionnaire (Tier 2), a clinical assessment by a qualified occupational health professional where something is flagged (Tier 3), and formal diagnosis and staging (Tier 4), with standardised testing available as Tier 5 where needed. The point of the tiers is to catch the earliest, still-manageable changes and act on them - by adjusting a person's tasks - before mild becomes severe.
None of this sits apart from the rest of your health-and-safety picture. The same crews exposed to vibration are often the ones working around grease, dust and airborne contaminants, and the same duty of care runs through both. The HSE's approach to controlling airborne hazards is set out in its local-exhaust-ventilation guidance, summarised in our HSG258 explained brief, and the discipline is identical: measure the real exposure, control it at source, and keep evidence that you did. Vibration and air quality are two halves of the same commitment to sending people home in the same condition they arrived.
Questions
No. Once the nerve and blood-vessel damage is established it does not heal, which is why HAVS is treated as a prevention problem rather than a treatment one. Catching the earliest changes through health surveillance and adjusting the work can stop it progressing, but it cannot undo damage already done. That is the whole case for acting on tingling or blanching fingers the moment they appear.
Under the Control of Vibration at Work Regulations 2005, the exposure action value is 2.5 m/s2 A(8) and the exposure limit value is 5.0 m/s2 A(8), both averaged over an eight-hour day. At the action value you must control exposure and provide health surveillance. The limit value is a legal ceiling that must never be exceeded.
Faster than most people expect. Because high-vibration tools accumulate exposure points quickly, some kit can take an operative past the action value in well under an hour of actual trigger time. That is why measuring real trigger time per tool, using the HSE calculator, matters far more than a rough sense of how long a job took.
Yes. A confirmed diagnosis of hand-arm vibration syndrome or of carpal tunnel syndrome linked to the use of vibrating tools is a reportable occupational disease under RIDDOR. The duty falls on the employer once a written diagnosis is received. This is one more reason to have proper health surveillance in place, since it is the route through which cases are usually identified.
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