12.1 Noise
Noise levels can vary widely from machine to machine depending on conditions of use. Persons
exposed to high noise levels, even for a short time, may experience temporary partial hearing
loss and continuous exposure to high levels can result in permanent hearing damage. The
Woodworking Machines Regulations require employers to take reasonably practicable measures
to reduce noise levels where any person is likely to be exposed to a continuous equivalent noise
level of 90 dB(A) or more over an 8 hour working day. Additionally, suitable ear protectors must
be provided, maintained and worn.
Machines identified as generating unhealthy noise levels should be appropriately marked with a
warning of the need to wear hearing protection and it may be necessary to designate particular
areas of the workplace as ‘Ear Protection Zones’. Suitable warning signs are specified in the
Safety Signs Regulations 1995. It may be necessary to construct a suitable enclosure, in which
professional advice should be sought.
Further information and references to practical guidance are contained in free leaflets available
from The Health & Safety Executive.
The list below outlines some of the variables that directly affect the noise level of the machine:
Hard stiff timber can mean more noise (approx. 2dB(A)
difference when cutting oak and pine) & more transmitted
noise.
Wide work pieces radiate noise over a greater area
increasing the noise level.
Thin workpieces generally vibrate more increasing the
noise level.
Long workpieces transmit noise away from the cutting area
towards the operator.
This affects the windage noise and increases roughly in
proportion to the width of cut.
Dull and worn blades exert more force on the timber thus
creating more noise.
Out of balance blades mean vibration and changes in
cutting conditions, resulting in increased noise levels.
Air Velocity/
System Design
Resonant conditions can lead to high noise levels,
excessive turbulence and chip impact can increase noise
levels substantially.
The following noise levels were recorded at a distance of one metre from the machine (operator
side), using varying feed rates and depths of cut.
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