IB6 Flashcards
A fire alarm engineer visits many customers’ premises during the working
day in order to check that fire alarm sounders are operating at the correct
sound level. The engineer does not wear hearing protection.
(a) Explain how the engineer may be at risk of hearing damage.
(b) Explain how the engineer’s personal noise exposure should be determined
(a)
A typical fire alarm sounds off between the 65db to 120 db, The damaging effects of noise are related to the total dose of energy that the ear receives. The dose is determined by two factors: the level of noise and the duration of exposure.
in our case the engineer would experience frequent but brief exposure to very loud noise that, over the course of time, could exceed legal limits and lead
to hearing damage.
(b)
-personal sound level meter/dosimeter would be used (given the fact that the engineer is highly mobile and the noise levels are likely to be highly variable from day to day).
-Before the survey is started, there should be consultation with the workforce, a competent assessor should be appointed.
-The equipment to be used should be calibrated before and after measurements
have been taken.
- The noise has to be measured At every location that the person works in or walks through during the day( not necessary to record noise below 75db).
- Fitting the dosimeter microphone close to the worker’s ear, but far enough away to avoid sound reflections (>15cm). place the microphone on the person’s shoulder (to prevent it touching the neck, etc.).
- Keeping of a daily work log (sources of exposure)
- Considering the alarm is either steady or cyclic sound can be measure for shorter period
- The dosimeter indicates LAeq (and ideally should have a data logging function) LAeq does not allow direct comparison with the legal standards. So the result needs to be converted to LEP,d the daily (or weekly) noise exposure (LEP,d).(HSE calculator, hse Ready Reckoner, use the equations can be used for this purpouse)
- A second more detailed noise survey could be required if the noise exceeds an upper exposure action value
(a)
Construction workers are at risk of developing hand-arm vibration syndrome (HAVS).
(i) Outline factors that may increase this risk.
(ii) Outline the steps of a health surveillance programme for workers who are exposed to hand-arm vibration.
(b)
A construction worker has been off work for a period of time suffering from HAVS and the employer’s occupational health department wants to find out if they are fit to return to work.
(i) Outline the way in which symptom severity of HAVS is classified using the Stockholm scale.
(ii) Outline options that the occupational health department can suggest to the employer if the occupational health doctor decides that the worker cannot return to the work that exposes them to vibration.
(a)
(i)
- the vibration magnitude and lack of equipment maintenance or condition
of the equipment
•The direction of the vibration put into the hand
•The frequency range of the vibration
•The duration of exposure (i.e. The length of time that an individual worker actually spends with their hands on the handles of the vibrating equipment with the equipment working)
• The need to use force to grip tools (holding the tools too tightly)
• Worker lifestyle also has an effect, with smokers being more at risk of the condition
• Any exposure to cold and wet conditions
• Any pre- existing circulatory problems (perhaps caused by previous exposures to vibration, or as a result of other conditions such as reynaud’s phenomenon).
(ii)
•The use of questionnaires on medical history as an initial baseline assessment
-annual screening questionnaire which is issued once a year to check whether worker exposed need to be referred for a HAVS health assessment.
• HAVS health assessment by a qualified person (eg an occupational
health nurse)which would involve assessment of grip strength(using a
dynamometer), vascular and neurological function
• a formal diagnosis and is carried out by a doctor qualified OH, advice for employee’s fitnes for work.
• referral of the employee for certain tests for HAVS.
The results may help the doctor assess fitness for work. ( Stockholm Workshop Scale.)(optional)
(b)
(I) The Stockholm Scale is subdivided into two components (the grading is made separately for each hand):
• Vascular (Blood Flow) Tests
These use a cold challenge to the hands (immersion in cold water):
– Time taken for the finger to return to full circulation after Cold Provocation Test (CPT).
– Finger Systolic Blood Pressure (FSBP) test.
• Sensorineural Tests (for Assessing Nerve Damage)
– Vibrotactile Perception Threshold (VPT) - based on perception of vibrations applied to the finger.
– Thermal (temperature) Perception Threshold (TPT) - based on subjective judgments on perception of ‘hot’
and ‘cold’ with the finger.
(b)
(II)
– A return to normal duties but with restriction meaning the work shall involve no vibration exposure.
– Adapting the existing job if possible to remove vibration exposure finally
– termination of employment on medical ground( pension benefits, the lump sum )
A manufacturer’s data on vibration emission from equipment can be used to estimate the exposure of workers to hand-arm vibration (HAV).
This manufacturer’s data is measured in a laboratory and can underestimate the actual vibration magnitude experienced by workers.
(a) Outline possible reasons for this difference.
(b) Outline how vibration emission from a hand-held tool might be measured.
(c) Outline the content of a training course for workers exposed to HAV
(a)
The condition of the tool:
-Maintenance issues that could affect the difference in magnitude measured
- the wear-and-tear that occurs as equipment ages
- the operators’ techniques
-The effects of material being worked on being a potential reason for the differences in vibration magnitude.
(b)
• Vibration magnitude can be measured directly using an accelerometer, or taken from manufacturer’s data. This data, in combination with duration of contact(trigger time), can then be used to reliably estimate personal exposures.
How?
• If using a vibration transducer (accelerometer that has three electronic sensors to measure viberation in all dimensions x, y and z) to take actual readings, then the instrument is firmly attached to the vibrating handle. Alternatively, published vibration magnitude data might be used, provided that data gives a reliable estimate of actual vibration magnitude exposures.
• and allowances
must be made to take account of ‘real world’ factors (such as the wear-and-tear that occurs as equipment ages). to reflect the real situation
For How Long?
• Measurements need to be sufficient to account for variations in the vibration magnitude that would naturally occur during the working day.
(c)
• The health effects of hand-arm vibration
• Sources of hand-arm vibration;
• How to recognise and report symptoms
• Ways to minimise risk including
-Changes to working practices to reduce vibration exposure;
- Correct selection, use and maintenance of equipment;
- Correct techniques for equipment use, how to reduce grip force etc;
- Maintenance of good blood circulation at work by keeping warm and massaging fingers and, if possible, cutting down on smoking.
• The need for health surveillance
• Whether they are at risk
• The risk factors( level of vibration, daily exposure duration)
An employer has identified that workers are exposed to high noise levels and has used the single number rating (SNR) method to select hearing protection, using the information below.
Sound pressure level 91dB(C)
SNR for selected hearing protection 29
(a)Using the data in the above table, calculateANDexplain how to determine a realistic estimate of the A-weighted sound pressure level entering the ear of the workers wearing this hearing protection
(b)
Comment on whether the attenuation that is provided by this hearing protection is appropriate.
(c)
IdentifyTWO other methods that could be used to determine if the hearing protection selected provides appropriate attenuation AND, for EACH of these methods, outline the data required in order to be able to calculate the attenuation provided by this hearing protection.
(d)
Other than noise attenuation, outline factors that the employer should consider when selecting hearing protection.
(a)
91-29=62db(A)
We must then make 4 db addiotional to take account of ‘real-world’ factors.
62+4= 66db(A)
So, a worker wearing the selected hearing protection would receive 66dB(A) at their ear
(b)
We must then evaluate this predicted exposure against the relevant legal standards.
If we use the UK/EU standards, we find that we may be below the UEAV (85dB(A)) and the LEAV (80dB(A)) but, unfortunately, we are also below the guideline 70dB(A), which shows that we are ‘over-protecting’ the worker’s hearing. This hearing protection is therefore not suitable for use in the workroom, so another type, offering a lower level of protection, should be found, (. Users become isolated from their environment)
(c)
- The octave band method is the most accurate but requires a full octave band spectrum of the noise in the workplace, as derived from octave band analysis.
- The HML method is less accurate if noise is dominated by single frequencies but only requires two bits of information about the workplace noise - A-weighted and C-weighted average sound pressure levels
(d)
• Comfort The more comfortable the device, the more likely your employees are to forget they are wearing hearing protection comfortable hearing protection will free movement, lightweight, comfortable to weark, adapted to the morphology of each ear.
- The hearing protection to be selected has to consider the need for communicationn, so the protection device allows a safe communication while exposed to noise communication demands
- use of other personal protective equipment
- Temperature and climate
- Existing hearing loss Workers who have existing hearing loss also need to be carefully considered. It is important to preserve their hearing while also ensuring they are able to hear critical conversations, workplace alarms, equipment warnings, etc.
- Convenience or ease of use.
- Use hearing protection devices that are easy to clean
• Personal preference Limiting hearing protectors to only one option will not address the needs of all
workers.
• Storage and maintenance requirement
Bulldozer drivers at a large construction site have reported incidences of back pain which they believe are caused by exposure to whole-body vibration.
(a) Outline a range of control measures that could be used to minimise the risk of the drivers experiencing
back pain caused by exposure to whole-body vibration.
(b) Identify THREE other possible work-related causes of the back pain being experienced by the bulldozer drivers.
(a)
Initial controls would include fitting suspension seats with vibration damping and improving suspension on vehicles.
Maintenance of vehicles and daily checks on conditions such as tyre pressure and suspension would also reduce vibration levels.
Job rotation would reduce the exposure time of drivers and heated seats and back support might reduce the actual risk of harm. Selecting seating to suit operators (taking into account their shape, size and weight) is also an important control
measure and provision of information to drivers on hazards and controls should assist compliance with the control measures in place. In the longer term, selection of low-vibration vehicles would minimise the overall risk.
(b)
– Poor posture of the driver caused by seat design or cab layout.
– The need to sit for extended periods without rest or movement.
– Lack of seat adjustment to accommodate the different range of drivers who may be required to use the equipment.
(a) Identify the risk factors associated with Hand-Arm Vibration Syndrome (HAVS).
(b) Outline a strategy for assessing the risk of HAVS amongst workers exposed to vibrating equipment
(a) Actual exposure to vibration, the magnitude of that exposure, the direction of the vibration put into the hand, the frequency range of the vibration, the duration of exposure (i.e. the length of time that an individual worker actually spends with their hands on the handles of the vibrating equipment with the equipment working), the need to use force to grip tools, any exposure to cold and wet conditions, any pre-existing circulatory problems (perhaps caused by previous exposures to vibration, or as a result of other conditions such as Reynaud’s phenomenon).
(b) That all of the equipment held in the hand with significant vibration magnitude should be identified. The workers at risk, i.e. the workers who actually use the identified hand-held vibrating equipment, must be identified. These workers’ exposure to vibration must then be reliably estimated by assessing the magnitude of risk (looking at tasks being performed, vibration frequency, duration of use, work methods, etc.). This estimation might make use of manufacturer’s data, but it may also require physical measurement of vibration magnitude using accelerometers. These estimated vibration doses must then be compared to the standards laid out in the Control of Vibration at Work Regulations 2005. For any employees identified to have an exposure at or above the Exposure Action Value (or workers with known conditions), health surveillance will be necessary. Exposures must be reduced below the EAV.
A worker in a workshop has to use three different machines during their typical working day.
(a) Explain how an estimate of the operator’s daily personal noise exposure (LEP,d) can be made from static measurements taken at each of these machines.
(b) The result of personal dosimetry on a typical day provides an LEP,d that is 4dB(A) greater than the estimate made in (a). Assuming that the duration of use of each machine is the same when both assessments were made, identify the factors that may account for this difference.
(a)
In order to make an estimation of the operator’s daily personal noise exposure (LEP,d) it would be necessary to measure the equivalent noise level at each machine (Leq) by using an Integrating Sound Level Meter (ISLM). This would have to be positioned in the region of the operator’s head during a period of machine operation to try to measure a truly representative noise exposure. A measurement or a reliable estimate would also have to be made of the amount of time spent at each machine. Using these two factors, the various Leqs at various machines and the durations of exposure at each machine, the daily personal exposure would be calculated.This requires the addition value on a log scale using logarithmic rules. Since this can be rather cumbersome, there are two reliable ways of arriving at an acceptable figure; using the UK’s HSE ready reckoner, which requires the addition of exposure points, or using the Lepd calculator on the HSE’s website noise microsite. Either method will give an acceptable degree of accuracy.
(b)
Actual differences may be due to differences in operating positions, machine speeds, materials used, etc. between the day of the ISLM use and the day of the personal dosimeter use. Alternatively, differences might result from the incorrect or inaccurate use of the ISLM technique, e.g. incorrect estimates of operating times, incorrect Leq (not using integrating sound level meter or measurements taken over too short a time), misuse/abuse of equipment, poor calibration, calculation errors, significant exposures missed (for static measurements). Finally, there might be inaccuracies with the use of the personal dosimeter such as a failure to correctly calibrate or misuse by the wearer.
(a) Review the principal characteristics of an audiogram, showing a typical pattern of hearing in an individual suffering from noise induced hearing loss.
(b) Outline the benefits and limitations of audiometry as part of a hearing conservation programme.
(a)
The graph shows the distinctive 4-6kHz dip. It shows little or no reduction in hearing levels at low frequencies (0.25-1kHz), but then marked reduction in hearing levels from 2-8kHz. The 4kHz dip shows noise-induced hearing loss, rather than presbycusis (where the reduction in hearing level continues as frequency increases). Both ears are affected to a similar degree
(b)The benefits of audiometry include:
Evidence of effectiveness of hearing conservation programme.
Pre-employment identification of pre-existing problems.
Identification of early signs of noise induced hearing loss.
Basis to defend claims of noise induced hearing loss.
Limitations of audiometry include:
Not preventive.
Information may precipitate claims.
Possible inaccuracies in data.
Doesn’t identify source of noise induced hearing loss.
(a) Review the different sorts of equipment that are routinely used to undertake noise measurement in workplaces. Outline the features and roles of EACH type of equipment in assessing noise exposure.
(b) Outline the strengths and weaknesses of audiometry as a method of protecting workers from noise-induced hearing loss at work.
(a)
Basic sound level meter - for spot checks. A simple sound level metre which would be capable of measuring sound pressure level on the A-weighting and C-weighting matrices. With analogue or digital readout. Useful for carrying out spot checks and initial surveys to spot problems, but not very useful for detailed surveys.
Integrating sound level meter - for integrating exposure to noise over the exposure period; A-weighting mode; equivalent daily noise exposure calculated from these measurements (and duration of exposure); peak action level; used to make noise measurements for purposes of noise regulations (must be at least Class 2 or Type 2).
Octave band integrating sound level meter (or ISLM with an octave band attachment) - important for analysis of sound for choosing ear protection and designing noise abatement controls. This type of meter can give the noise contributions at various frequency bands across the human hearing spectrum
Dosimeters - personal noise exposure over working day; worn by worker, often data downloaded wirelessly. This metre is usually small and portable and may not have any form of read-out for the wearer to look at. Useful for assessing the exposure in workrooms where workers move around a lot, or fluctuating noise levels make ISLM use difficult.
All must be calibrated and therefore a calibrator is essential
(b)The strengths of audiometry are:
Pre-employment baseline testing for new or prospective employees.
Identification of early signs of noise-induced hearing loss so as to be able to remove affected workers from high noise areas.
Monitoring the effectiveness of any hearing conservation programme on the basis that if the programme is working, then audiometry will show no significant Noise-Induced Hearing Loss (NIHL) cases.
The weaknesses of audiometry are:
Making sure operators are not exposed to high noise levels prior to test (causes temporary threshold shift which skews the results).
It is an inherently reactive technique - the damage has already been done.
The results of audiometry may be used to support civil claim against the company.
A noise assessment carried out by a soft drinks manufacturing plant has revealed that personnel working in the vicinity of an automatic bottle filler are exposed to noise levels in excess of acceptable limits. It has been decided to investigate engineering methods of reducing noise exposures. Review, for the works manager, the purpose and essential design and construction characteristics of:
(a) an acoustic enclosure.
(b) an acoustic haven.
(a)
An acoustic enclosure is designed to enclose equipment and contain the noise.
In order to design it correctly, octave band analysis will be necessary to characterise the nature of the noise source. The noise reduction index of the panelling of the enclosure will have to be selected to give an appropriate attenuation at the various frequencies needed. Ideally the enclosure would be a sealed airtight unit. However, access for operation and maintenance of the enclosed machinery will be necessary. Therefore double-glazed observation windows and an airtight access door will be needed. Adequate internal space must be provided to allow all necessary access and maintenance works. Adequate lighting and ventilation will have to be provided for any workers who have to occasionally access the enclosure.
With regards to the construction of the enclosure, protection of the internal absorbent lining is essential to protect it from simple mechanical damage. Sealing between panels and the floor, and around penetrating ducts and pipes will be essential to ensure that there is not an air path for noise to take out of the enclosure. Flexible connectors for pipes and ducts may be necessary to prevent vibration from being conducted out of the enclosure which will then provide a simple route for noise passage. Robust locks should be fitted to doors and hatches. Acoustic louvres may be required to vent the enclosure.
(b)
An acoustic haven is designed to provide a relatively quiet haven for workers to protect themselves from workplace noise. Workers in the haven should be able to remove their hearing protection.
With regards to design, again octave band analysis will be necessary to characterise the nature of the noise sources. The noise reduction index of the panelling of the enclosure will need to be specified using this information. Double-glazed observation windows, so that workers can see out into the workplace, will be necessary. Adequate internal space and adequate lighting and ventilation are of course essential, since workers may be occupying this haven for quite significant periods of time. Adequate seating must also be provided. As many controls as possible should be brought into the haven to reduce time spent outside in the noisy environment.
The construction of the haven is similar to that of the enclosure. Attention must be paid to sealing between panel and floor, and around penetrating ducts and pipes. Again, robust locks to doors must be fitted and the haven overall must be of robust construction.
A large print works, employing 70 workers, operates four printing presses and has associated work activities, such as collating, binding and packing of product. Noise is a significant health problem at the works.
(a) Identify the issues that should be taken into account before starting a noise survey within the print works.
(b) Explain how a noise survey could be conducted, identifying the types of survey equipment that would be used to assess worker exposure to noise.
(a)
Before undertaking a survey of the print shop, a visit to the work area would be advisable in order to determine if there is a noise problem; if you cannot hear normal speech at a distance of two metres, then there is. One factor to consider prior to the survey would be the persons who are at risk and, in particular, any individual susceptibility to noise (for example pre-existing noise induced hearing loss). The duration of worker exposure to the noise would be another factor; this might be determined by work patterns and shift patterns and might mean that certain groups of workers were not at risk whilst others might be. It should also be possible to determine which machines and activities are producing the noise and whether they are all used at the same time, and for how long. Another factor to consider would be existing precautions that are in place already. The results of previous noise surveys and assessments would also need to be taken into consideration.
(b) In undertaking a noise survey one important decision would have to be made that would heavily influence the procedure adopted: which type of survey meter to use. There are two alternatives here, either an Integrating Sound Level Meter (ISLM) (type II, class II or better), or a personal dosimeter could be used. The latter is ideal for situations where operators move around constantly in a workplace and so cannot be assigned a workstation for a significant period of their exposure time. Whichever meter is opted for, it is essential to test the meter batteries and its calibration. This must be done with a calibrator which is itself within its calibration test date.
Both types of meter must have dB(A) and dB(C) weighting matrices available and both must be capable of providing Leq and Lcpeak readouts.
A night club hires musicians and DJs to play live and pre-recorded amplified music daily, from a stage. In the same room is a bar where workers are employed serving drinks.
Following personal noise exposure monitoring, a high risk of excessive noise exposure was identified for all workers in the bar area. Suitable hearing protection has been provided to all the bar workers.
Other than the provision of hearing protection, outline control measures that could help reduce the risks to the bar workers’ hearing.
- Frequent breaks away from the noise or in a quiet room, Creating a noise haven for the employees.
- Training of workers in the risks associated with exposure to high noise levels
- Eliminating unnecessary exposure such as avoiding noisy activities, for example, sound system checking while employees are working adjacent to loudspeakers.
• Controlling the noise at the source by reducing the
sound output from individual instruments such as damping drums or closing piano lids, leading to an overall reduction in volume, Fold-back levels on the stage should be reduced to the minimum level at which it is possible to work.
• Noise can also be controlled by the careful design of the premises, for example by using acoustic
absorption panels. Adding an acoustic ceiling, acoustic wall linings, or carpeting may
increase acoustic absorption.
• Sound-level adjustments can be more readily carried out where amplification is used and it is simple and highly effective to turn the amplified sound down. However, it is essential to monitor sound levels to ensure they are not increased again above
acceptable levels.
- A control mechanism within the sound system may help, by providing a warning (or limiting) when a preset sound level is reached.
- increasing the distance between front-of-house workers not on stage and the stage area and loudspeakers.
- Ensure the musicians and dj is in a suitable location facing the majority of the audience and preferably not the bar or other work areas.
- Soundproofing should be considered for doors, windows and other ‘leaky’ areas – especially if it prevents spill into otherwise quiet areas.
- Re-orientate the stage and/or loudspeakers to direct less sound towards staff locations. Where there are multiple speakers,
• Acoustic screening can be helpful to protect specific workers and locations from direct noise sources, for example, technicians, bar staff, front of house.
The effectiveness of screens depends on their design and location(s) which need to be carefully considered.
• Install vibration isolation mounts to loudspeakers to prevent noise from entering the building structure.
A small printing company operates a number of printing machines which are located in an open-plan workshop. Following a noise survey, the company discovers that their workers are being exposed to high average daily noise levels. The noise levels exceed regulatory exposure limits.
(a) Describe the acute and chronic physiological effects of exposure to high noise levels on the individual.
(b) Explain what steps the company should take to protect workers.
In your answer clearly explain the range of technical and organizational control measures that could be introduced.
(a)
Tinnitus (ringing in the ears) which may be a chronic or acute, temporary or permanent threshold shift and noise-induced hearing loss resulting in a loss of sensitivity to sounds in the speech range. This part of the question is generally poorly answered with many candidates showing little awareness of the physiological effects of exposure to high noise levels or at least providing too little detail to gain marks
(b)
replacing older/noisier equipment with machines that
emitted lower levels of noise; isolating the noisier machines in a separate area of the workshop and building a noise enclosure of suitable noise attenuating material around them; mounting the noisy equipment on rubber strips or dampers; lining the walls and floor of the workshop with acoustically absorbing material and applying damping to metal panels on machines; and creating a noise haven for the workers. If even after taking the above measures, the provision of hearing protection is found to be necessary, it should be chosen based on an octave band analysis measurement of the noise emitted in order to provide the best overall reduction in exposure.
Organizational controls include reducing exposure times by job rotation; designating hearing protection zones; providing training to workers on the risks associated with exposure to noise and on the fitting and maintenance of hearing protection; ensuring
hearing protectors, once issued, are used and introducing disciplinary procedures to deal with those workers who do not wear them. Establishing a maintenance regime for equipment is also relevant.
A worker is using a hand-held jackhammer to break up a large area of concrete. Jackhammers produce high levels of noise and vibration.
(a) Outline the possible ill-health effects to the worker from the prolonged use of jackhammers to break concrete. (5)
(b) Outline actions that the worker can take to help reduce the risks from their exposure to the noise and vibration of this work
activity. (7)
(c) Review the similarities and differences between hand-arm vibration exposure assessment and noise exposure assessment. (8)
(a)
• Circulatory disorders (blanching of the fingers, Raynaud’s Disease)
• Neurological disorders (numbness and tingling).
• Muscular effects (difficulty with grip and reduced dexterity).
• Articular effects (bone and joint problems).
• Carpal tunnel syndrome (compression of the median nerve in the wrist)
• Noise-Induced Hearing Loss (NIHL) is permanent threshold shift caused by exposure to excessive noise.
Temporary Threshold Shift (TTS), Permanent Threshold Shift (PTS) with temporary/ permanent reduction in hearing acuity,
•Lung damaged from the dust generated by the task.
(b)
(c)
differences:
That noise measures sound pressure in decibels, whereas vibration measures acceleration in metres per second squared.
The noise dose is determined by two factors: the level of noise and the duration of exposure, whereas the vibration dose is determined by the magnitude of the vibration (RMS acceleration) and the duration of exposure.
Similarities:
The daily dose of vibration received by a worker the eight-hour energy-equivalent vibration magnitude where the noise dose the equivalent continuous daily personal noise exposure level both are ‘standardized to an eight-hour reference period’ and both can be expressed as a daily persona exposure.
Workers driving vehicles on a large construction site have reported back
pain caused by exposure to whole-body vibration (WBV).
(a) Outline control measures that could minimize their exposure to WBV.
(b) Outline other possible work-related causes of the back pain being experienced by these workers.
(a)
• Selection Vehicle low-vibration or anti-vibration features in their design, for example, antivibration cab and seat suspension systems.
– Establish a purchasing policy that specifies vibration as one criterion of selection and vet new equipment on
this basis.
– Choose equipment that is going to be suitable for the job and environment of use (e.g. adequate load capacity, right size wheels for the terrain, capable of required speeds, etc.).
– In particular, focus on the suspension systems for seats, cabs and vehicle body, all of which isolate the driver from the movement of the tyres over rough ground.
• Care and Maintenance
– Balance wheels to eliminate judder.
– Maintain any anti-vibration devices or features (such as seat or cab suspension systems).
– Maintain traffic routes by grading surfaces and filling potholes to keep surfaces as smooth as practical.
• Reduced Time Exposure
– Job rotation and rest breaks can reduce exposure time.
– Maximum duration of use can be applied to vehicle and plant provided reliable vibration magnitude data is
available.
• Information, Instruction and Training
– Information on the risks of exposure to WBV and the associated health conditions should be provided.
– Instruction and training on the control measures to minimize the risk should be given. This will relate to vehicle use, care, and maintenance.
(b)
– Poor posture of the driver caused by the seat design or cab layout.
– The need to sit for extended periods without rest or movement.
– Lack of seat adjustment to accommodate the different range of drivers who may be required to use the equipment.
