Introduction to Health and Safety at Work

Hand-arm vibration
Many machines and processed used in industry produce 
hand-arm vibration. Typical high risk processes include:
➤
grinding, sanding and polishing wood and stone
➤
cutting stone, metal and wood
➤
riveting, caulking and hammering
➤
compacting sand, concrete and aggregate
➤
drilling and breaking rock, concrete and road sur-
faces, and
➤
surface preparation, including de-scaling and paint 
removal.
There are several ways to ascertain the size of the 
vibration generated by equipment and machines. 
Manufacturers must declare vibration emission values 
for portable hand-held and hand guided machines and 
provide information on risks. Other important sources 
for vibration information include scientifi c and technical 
journals, trade associations and on-line databases. HSE 
experience has shown that the vibration level is higher in 
practice than that quoted by many manufacturers. The 
reasons for this discrepancy may be that:
➤
the equipment is not well maintained
➤
the equipment is not suitable for the material being 
worked
➤
the accessories are not appropriate or badly fi tted, or
➤
the operative is not using the tool properly.
Figure 15.4
Mounted breaker to reduce vibrations.

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Physical and psychological health hazards and control
255
In view of these problems, it is recommended that the 
declared value should be doubled when comparisons 
are made with exposure limits. Since the exposure limit 
or action value is averaged over 8 hours, it is possible 
to work with higher values for a reduced exposure time. 
Table 15.3 shows the reduction in exposure time as the 
size of the vibration increases.
The Guidance (L140) gives very useful advice on 
the measurement of vibration, undertaking a suitable 
and suffi cient risk assessment, control measures, health 
surveillance and training of employees. The following 
points summarise the important measures which should 
be taken to reduce the risks associated with hand-arm 
vibration:
1. avoid, whenever possible, the need for vibration 
equipment
2. undertake a risk assessment which includes a 
soundly based estimate of the employees’ exposure 
to vibration
3. develop a good maintenance regime for tools and 
machinery. This may involve ensuring that tools are 
regularly sharpened, worn components are replaced 
or engines are regularly tuned and adjusted
4. introduce a work pattern that reduces the time ex-
posure to vibration
5. issue employees with gloves and warm clothing. 
There is a debate as to whether anti-vibration gloves 
are really effective but it is agreed that warm clothing 
helps with blood circulation which reduces the risk 
of vibration white fi nger. Care must be taken so that 
the tool does not cool the hand of the operator, and
6. introduce a reporting system for employees to 
use so that concerns and any symptoms can be 
recorded and investigated.