Hand Arm Vibration Syndrome (HAVS) Robert Tailby, Loss Control Specialist with Chubb Insurance, answers some commonly asked questions about a problem that some companies are still not dealing with adequately. What is it?
How do you get it?
second squared averaged over an
Any work activity that transmits
8 hour working day. The accepted
Hand Arm Vibration Syndrome (HAVS)
vibration to the arms and hands could
way to express this is 5 m/s2 A(8).
refers to a range of health effects
create a risk. This includes using
Although the overall maximum dose
that happen when the nerves, blood
hammer drills, sanders, grinders, disc
limit is 5 m/s2 A(8), employers have
vessels, muscles and joints of the
cutters, rotary polishing tools, and
to take action to reduce vibration
hand, wrist and arm are damaged by
concrete breakers, as well as hand-
exposure if their employees dose
prolonged exposure to vibration.
guided equipment such as powered
exceeds 2m/s2 A(8).
lawnmowers, chainsaws, hedge What are the effects?
trimmers, floor sanders and the like.
If the magnitude of vibration from a
The most well known symptom of
Regularly using this type of equipment
particular tool or process is relatively
HAVS is vibration white finger (VWF).
for prolonged periods is a common
low, it will take a long time for a
During an attack of VWF, sufferers
cause of HAVS. Holding materials
worker’s exposure to reach the daily
fingers go numb and turn white
being processed against machines
dose limit; if it is high, the limit
(blanching), and then become red
such as bench-mounted grinders,
could be reached quite quickly. For
and painful as they recover. These
pedestal grinders and polishing mops
example, if a tool vibrates at 3 m/s2, a
symptoms are often brought on by
can also create significant vibration
dose of 2 m/s2 A(8) will be reached in
cold or wet conditions. People with
around 4 hours, but if the magnitude
HAVS also experience: • pain in the wrists (Carpal Tunnel
of vibration is 10 m/s2, the same dose
How much vibration causes HAVS?
will be reached in only 30 minutes.
complicated. All that most of us
How do I know if there is a problem?
need to know is that there is a legal
If your tools and equipment are
• loss of grip strength
maximum daily vibration dose limit.
relatively new, the manufacturer
• tingling sensations (pins and
If workers’ vibration exposure is kept
should be able to tell you how much
below that limit then the risk of HAVS
vibration they are likely to generate.
will be low.
By timing how long people use each
Syndrome) • pain or loss of sensation in the hands or fingers
needles) • loss of manual dexterity (can’t do
The science of vibration is quite
fine work, or pick up small objects) • loss of sense of temperature in the
piece of equipment you can work out The unit of measurement for vibration
their likely vibration dose1. If it looks
is meters per second squared (m/
like the exposure might be at or near
s2). Vibration dose is calculated by
the dose limit, you should do a more
With prolonged vibration exposure,
combining the magnitude of the
these effects become irreversible.
vibration in m/s2 with how long
someone is exposed. The overall legal
If you can’t get exposure data from
vibration exposure dose limit for an
equipment manufacturers, or the
individual worker is five meters per
vibration arises from how you do the
Spring 2010 edition of Risk Manager Magazine