REDUCING THE RISK OF HAND-ARM VIBRATION
By James M. Meyers, Director, California Farm Safety Program
You’re busy felling trees on a cold,
wintry day, and begin feeling
numbness or tingling in your fingers.
You take off your gloves, look at your
fingertips, and realize that they have
turned pale, white or blue. When you try
to unzip your jacket, you have trouble –
then you pick up a small tool, and notice
clumsiness with your hands that wasn’t
What is happening? It’s likely that
you’re experiencing symptoms of handarm
vibration syndrome (HAVS), also
known as “white finger,” “dead finger,” or
Raynaud’s phenomenon. HAVS, commonly
caused by the repeated and frequent
use of chain saws and other
handheld vibrating tools, is a potentially disabling condition
of the fingers, hands and arms. Its most noticeable
symptoms are bouts or attacks of poor blood circulation typically
triggered by cold weather or by touching a cold object.
Hand-arm vibration syndrome is common in the forestry
industry. In fact, the Canadian Centre for Occupational
Health & Safety cites one study showing that 50 percent of
146 tree fellers examined in British Columbia had Raynaud’s
phenomenon; a full 75 percent of the workers with
more than 20 years experience were affected by it.
Even if hand cutting is no longer a significant part of
your operation, the use of chain saws or other vibrating
tools in the past by you or your workers may mean that
damage has already been done. The good news, though, is
that by identifying the hazards that may result in HAVS –
then taking steps to reduce those hazards – you can help
prevent the disease from occurring in other employees
and/or from progressing to a more serious stage in those
who already have it.
Identifying the Hazards
One step that you can take is to choose chain saws with
built-in anti-vibration features. It is important to note, however,
that workers who use chain saws daily may still develop
HAVS. Be sure when choosing chain saws that you
ask the supplier for documented evidence that the saws do
in fact reduce vibration.
Here are some more suggestions:
• Maintain the saws according to the manufacturer’s instructions.
In particular, be sure that the anti-vibration
mountings are changed at the specified intervals.• Provide chain saws that are fitted with heated handles.
• Provide workers with anti-vibration gloves. Although
anti-vibration gloves have not been proven to be effective
in preventing HAVS, those gloves that meet the international
anti-vibration glove standard (EN ISO
10819) are much improved in their ability to
damp vibration over earlier gloves. Choose
these gloves carefully; some manufacturers
have better “track records” than others. In addition
to damping vibration, be sure that the
gloves you choose:
•are full finger gloves (particularly when
working in cold conditions). Note: While the
risk of HAVS is increased by cold weather, persons
working in hot climates can also suffer
•keep the fingers dry by wicking hand perspiration.
Note: Glove liners may also do this.
• When possible, reduce the amount of time
your workers use chain saws or other handheld
vibrating tools. Also, encourage them to
take breaks from using the tool (10 minutes per every hour
of use is recommended) – or, as an alternative, to alternate
tasks between vibrating and non-vibrating tools.
• Discourage smoking – the chemicals in tobacco can affect
blood circulation and increase the risk or severity of
Training Your Workers
It’s also important to train your workers to recognize the
symptoms of HAVS, to report them as early as possible, and
to take steps themselves to reduce their risk of contracting
the disease. The following information can be passed onto
• Know the symptoms of hand-arm vibration. These
may include: numbness, tingling, throbbing and pain in one
or more fingers; fingertips that turn cool and pale or blue,
and can go bright red; and difficulty picking up small objects
and/or buttoning or zipping clothes.
• Be aware that these symptoms generally come in bouts,
typically triggered by cold weather or by contact with a cold
• Know that tobacco use can increase the risk or severity
of hand-arm vibration. Use hearing protection, and do
not smoke or chew tobacco.
• Keep your hands and fingers warm. Wear anti-vibration
gloves that cover all of your fingers, and make sure you
have a proper fit.
• Hold chain saws and other tools as loosely as possible.
Don’t excessively “grip” the tool.
• When possible, limit the amount of time you use vibrating
tools. Take regular short breaks, and, when possible,
alternate your work between vibrating and non-vibrating
The California Farm Safety Program is a cooperative effort of
USDA and the University of California.
service is temporarily unavailable