Download Noise - Policy and Director`s summary Jan 2007

Noise
Policy and Director’s summary
Policy and guidance on control and management of noise
in the workplace
Policy and Guidance
Version 2 April 2007
Noise
Policy and Director’s summary
NOISE
Policy
The policy of the Medical Research Council is to ensure that all staff work within a safe
environment and work to best practice to ensure their health, safety and welfare
within the workplace. The MRC requires that its directors and external scientific staff
(ESS) team leaders assess whether noise may present a hazard to or impair the work
efficiency of staff or visitors. Measures must be introduced to remove or control the
unwanted noise.
Scope
This document examines the procedures and practices which should be in place to
comply with “The Control of Noise at Work Regulations 2005’. The document also
draws attention to unwarranted noise not covered by the regulations and gives
appropriate guidance to Unit directors, team leaders and supervisory staff on how to
assess and control noise levels in both categories.
Responsibilities
The director or ESS team leader is ultimately responsible for ensuring that the present
policy is carried out.
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Noise
Policy and Director’s summary
Director’s Summary
Noise can be defined as “unwanted sound” which may have a significant effect on the
health and welfare of individuals if left uncontrolled.
Noise levels at or above those described in “The Control of Noise at Work Regulations
(CNAWR) 2005” may lead to hearing impairment and possibly permanent damage to the
hearing mechanism. Individuals must be protected from exposure to excessive noise.
•
Directors and ESS team leaders need to determine whether any individuals are being
exposed to noise levels at or above the noise action levels.
•
Where excessive noise levels are suspected then a noise risk assessment must be
carried out by a competent person
•
Noise risk assessments must be recorded
•
Appropriate steps must be taken to control or reduce the level of noise to ensure the
safety of individuals.
This document also draws attention to sources of unwanted noise that may affect the
health and work performance of individuals and gives guidance on what to do if a source
of unwanted noise is identified.
•
Directors and ESS team leaders should be aware that individuals may be affected by
unwanted noise.
•
Procedures should be in place to control or reduce “as far as is reasonably
practicable” noise levels which impairs performance levels.
MRC Health, Safety and Security
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April 2007
Noise
Policy and Director’s summary
Background
Noise itself is transmitted through the air as sound waves varying in frequency (the
pitch) and energy level (the amplitude). Sound pressure is measured in Pascals (Pa) and
the average human ear has a range of detecting pressure from 20uPa to 200Pa.
The hearing mechanism within the human ear has evolved into an extremely sensitive
organ capable of detecting sound intensity over a wide range. Sound intensity (the
physical level of noise) is determined on a logarithmic scale measured in decibels (dB).
Human hearing measurements are weighted since the human ear differs in its sensitivity
to different frequencies. The common weighted measurement (A-weighted) for human
hearing is expressed as dB(A).
Damage to hearing falls into two major categories. These are “acute effects” which are
normally reversible and include “acute acoustic trauma” (from gunfire or explosions) and
“temporary threshold shift” (TTS). Both normally result from intense stimulation of the
auditory nerves in situations where a constantly high level of noise exists e.g. cinemas,
disco etc. However, in some instances acoustic trauma from gunfire or explosion can lead
to rupture of the tympanic membrane resulting in non-reversible hearing loss. In
comparison “chronic effects” to the hearing mechanism will normally result in permanent
damage. Noise induced hearing loss (occupational hearing loss) which results in auditory
fatigue and permanent threshold shift (noise induced deafness) are examples of the
latter since both are consequences of the effects of long duration exposure to excessive
noise levels.
The Control of Noise at Work Regulations (CNAWR) 2005 is designed to protect
individuals from suffering the damaging effects that prolonged exposure to excessive
noise can do to their hearing. The regulations determine three dB(A) action levels which
if attained require employers to put into place controls to reduce “as far as is reasonably
practicable” the noise to which any employee is subject.
The first action level is at 80dB(A), the second at 85dB(A) with a peak sound pressure of
135dB for the lower limit and 137dB for the upper limit, both being C-weighted. The
action levels, with the exception of the peak level, are determined by measuring
exposure to levels of physical noise over a specified time period resulting in a daily or
weekly personal noise exposure or (LEP,d). The exposure limit values on a daily or weekly
basis are 87dB (A-weighted) and a peak sound pressure of 140dB (C-weighted). These
latter values must not be exceeded.
For the majority of MRC employees the CNAWR will not apply. However, it must be borne
in mind that there are other noise sources whilst not necessarily leading to hearing
damage can nevertheless be both annoying, distracting or disturbing to people at work.
Examples include noisy computer printers or photocopiers working within a relatively
confined area, centrifuges and freezers badly sited within either laboratories or corridors
and unprotected ultra-sonic devices used to disrupt tissue and cellular materials.
Although there is no physiological damage, exposure to annoying sound can be very
tiring and stressful. External sources may also produce excessive noise. These may
include air extractors, externally sited air conditioning units or traffic noise.
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Noise
Policy and Director’s summary
Noise levels which do not attract the provisions set out in the CNAWR may come under
The Health and Safety at Work etc. Act 1974 (HSAWA). This states that controls should
be introduced if, within any activity, it is shown that it poses a risk to the health and
welfare of individuals.
Unwanted noise may fall into this category.
Consideration should be given to the type of work being carried out as this will have
some bearing on whether or not a certain noise level is acceptable.
Consideration should also be given to the type of equipment being used, its noise level
and its position relative to personnel.
Requirements
The MRC requires directors and ESS team leaders to take the following steps if it is
suspected that an MRC employee or visitor is being subjected to physiologically
damaging noise levels.
A simple rule of thumb is that if you are required to shout to hold a conversation when
you are standing within 3 feet of a person then it is too noisy and the noise level should
be measured to ascertain what action should be taken.
On measuring exposure to noise and finding that it exceeds the first action level
(80dB(A)) then you are required to carry out a suitable and sufficient risk assessment
that should address:
1. The working practices making changes whenever necessary to reduce the noise level.
2. Ascertain the probable noise arising from the use of equipment and if necessary.
3. Measure the level of noise that the employee may be exposed to during his/her work.
If exposure to noise is at or exceeds the second action level (85dB(A)) or exceeds the
exposure limit values, then you are required to carry out a risk assessment that
considers the following:
1. The level, type and duration of exposure including any exposure to peak sound
pressure.
2. Assess the effects of exposure to noise on any person whose health may be at risk
from such an exposure.
3. As far as is practicable determine the interaction between the noise and any ototoxic
substance being used and the adverse effects on the health and safety of the
employee.
4. Assess the risk to the health and safety of the employee if there is a relationship
between the noise source and vibrational disturbances.
5. Assess whether there are any indirect effects on the health and safety of employees
between noise and audible warning signals or sounds that require to be audible to
reduce the risk at work.
6. Examine whether alternative equipment can be used.
7. Ensure that no additional exposure could happen at the workplace beyond normal
working hours eg during rest periods.
8. Provide information to the employee concerned following any health surveillance.
9. Provide hearing protectors with the correct attenuation characteristics.
10. Introduce hearing protection zones and manage them by providing training,
instructions and supervision.
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Noise
Policy and Director’s summary
The general requirement is to reduce noise “so far as is reasonably practicable” and this
applies to all action levels.
The flow chart on the following page illustrates the procedures that need to be followed
to minimise any noise hazard.
It is highly unlikely that MRC employees will be subjected to noise levels at or near the
second action level. Some tasks such as working in a print room may be at or near the
first action level.
It is probable that research specifically aimed at the measurement of hearing efficiency
using specific noise frequencies over a specified time will require that the noise levels to
which staff, patients or volunteers are subjected to is accurately monitored.
Your Regional Health and Safety Co-ordinator will advise you on how to measure noise
levels.
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Noise
Policy and Director’s summary
Managing Noise Risks
Assess the risks
Identify noise hazards
Estimate likely exposure to noise
Identify measures required to eliminate or reduce risks, control
exposures and protect employees
Make a record of what you will do in an action plan
Protect your employees
Worker information and training
Eliminate or control noise risks
Consult
workers
participation
Eliminate or reduce risks using good practice and known
control and management solutions
and
Make sure the legal limits on noise exposure are not
exceeded
And provide hearing protection
Health surveillance
Protect your employees with hearing protection
Provide health surveillance (hearing
checks) for those at risk
Manage the use of hearing protection with zones, instruction
and supervision
Use the results to review controls
and further protect individuals
Employees co-operate and attend
for hearing checks
Maintain and use the equipment
Maintain any noise-control equipment and hearing protection
Ensure that anything supplied is fully and properly used
Employees use the controls provided and report any defects
Employees use hearing protection where its use is mandatory
Review what you are doing
Review as things change:
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Changes in work practices
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Changes in noise exposures
•
New ways to reduce risks
their
Give employees information, instruction
and training about the risks, control
measures, hearing protection and safe
working practices
For the higher-risk cases, plan and put in place technical
and organisational noise-control measures
Make its use mandatory for the high-risk cases (keep
working on technical and organisational control measures)
allow