Unit GC 2 – Controlling workplace hazards Element 8: Physical and psychological health hazards and control Flashcards
The acute and chronic effects of exposure to noise
Acute effects
Stress; increased blood pressure
Temporary threshold shift
Temporary tinnitus
Blast deafness – single traumatic event causing permanent loss of hearing
Chronic effects
Noise induced hearing loss caused by long term exposure to loud noise
Permanent threshold shift
Permanent tinnitus
Prebyacusis – hearing loss across the whole range of frequencies
Factors that will determine the amount of hearing damage caused by noise
- Length of exposure
- Loudness of noise
- The frequency will have some effect on the damaged range
Identify the values, in dB(A), of, and outline the actions necessary for both the Lower and Upper Exposure Action Values
Lower Exposure Action Value 80 dB(A)
Carry out a risk assessment to identify the noise sources, exposure levels, people who may be exposed and further control measures where necessary.
Provide hearing protection if a worker asks for it.
Provide suitable and sufficient information, instruction and training on the noise hazards, risks and controls.
Upper Exposure Action Value 85dB(A)
Implement a formal noise control programme
Provide hearing protection and make sure the workers use it properly
Identify hearing protection zones and mark them with appropriate signs
Provide health surveillance to identify hearing damage.
Carrying out a simple noise survey
- Identify the area to be surveyed and the points at which measurements will be taken.
- Select a suitable noise meter and ensure that it is calibrated and that the battery is in good condition.
- Select the correct scale on the meter for the particular survey being carried out and take readings at the pre-determined points.
- Plot the readings on a plan showing the relationship to the source(s) of noise.
- Use the readings to determine compliance with the Control of Noise at Work Regulations.
Methods of reducing potential hearing damage in a noisy workplace
Source of noise
Reduce noise output by designing it out, e.g. using non-metallic parts.
Damping and isolating the vibration by using rubber mountings
Ensure equipment is well maintained
Noise path
Place screens and barriers between the source and people
Enclose the equipment in sound proof booths or rooms
Use energy absorbing panels to reduce the amount of rebound
The Person
Increase the distance between the noise source and people
Reduce the amount of time exposure
Raise awareness of noise risks by giving proper information and training
The limitations of hearing protection as a means of noise control
- Not worn correctly
- Not fitted correctly
- Not properly maintained
- Uncomfortable or inconvenient to wear
- Needs constant management commitment
- May introduce secondary risks
The purpose of health surveillance (hearing tests) as part of noise control measures
Hearing tests when starting at an organisation establishes a base line to determine whether hearing is deteriorating during subsequent tests. It helps to determine whether controls are adequate.
Six common sources of vibration during construction work
- Pneumatic tools
- Percussion tools
- Rotary tools
- Construction vehicles
- Vibrating pokers
- Vibrating rollers
Outline 6 possible effects of vibration on the hands of exposed workers.
- Vibration white finger
- Numbness
- Tingling /Pins and needles
- Loss of sense of touch
- Painful wrist
- Inability to grip
Outline 6 factors that may influence the risk of harm from using hand operated equipment
- Vibration magnitude rating of equipment
- Frequency and duration of exposure
- Cold conditions
- Wet conditions
- Tightness of grip
- Existing medical conditions
With regards to the UK’s Control of Vibration at Work Regulations, the exposure action value (EAV) for hand arm vibration is
A daily exposure of 2.5 m/s² (averaged over 8 hours)
With regards to the UK’s Control of Vibration at Work Regulations, the exposure limit value (ELV) for hand arm vibration is
A daily exposure of 5 m/s²
Factors that should be considered when carrying out a vibration risk assessment
- The type of equipment being used
- The type of work being carried out
- How the equipment is used and ergonomic considerations (posture, weight of equipment, space) The length of ‘trigger time’
- Do operators have existing problems
- Any relevant available information from manufacturers
Outline 6 control measures to reduce the risk of harm from vibrating hand held equipment
- Avoid use of equipment – do the job a different way
- Use equipment with lower vibration magnitude
- Reduced time of exposure (Job rotation)
- Keep hands warm
- Avoid working in wet / cold environments
- PPE (gel pad gloves)
Different types of non-ionising radiation common in workplaces
Infrared - Night vision; hot work such as brazing; any ‘red hot’ substance
Lasers - Laser pointers and levels; pattern cutting; bar code readers
Microwaves - Food preparation, Signal transmission
Ultra-violet - Arc welding; sun lamps
Typical health effects caused by exposure to non-ionising radiation
External burns to exposed skin Reddening of the skin (common after prolonged exposure to the sun) Cataracts (opacity of the lens of the eye) Arc eye after unprotected ‘flash’ from arc welding Temporary sterility
Outline 6 control measures that may be implemented to reduce the effects of exposure to nonionising radiation
Don’t work in direct sunlight – redesign the task to provide shade
Personal protection (hats / clothing etc) to protect against sunlight
Maintain work equipment
Training and information
Visors / welding goggles
Safe system of work
Identify two types of ionising and non-ionising radiation and give an occupational source for each
Ionising:
Gamma Rays - are emitted continuously and have great penetrating powers. Possible sources and occupation use of gamma rays is in pipe leaking tracing, non-destructive testing (e.g. welds) and in medical treatment of cancers.
X-ray - machines provide an example of man-made radiation. The radiation energy is only emitted wen the equipment is operating. The main source of x-rays in the workplace is in radiological equipment, and the main use of x-rays is medical diagnosis.
Non-Ionising
Ultraviolet radiation - possible sources of UV radiation is sunlight, arc wielding, sun beds and sun lamps. UV radiation sources may redden skin producing burns and skin thickening or cause eye inflammation and cataract formation
Electromagnetic fields (EMFs) - power frequencies, microwaves and radio frequencies. Occupations that would work with EMFs include Auto Mechanics, Electromagnets are used in large automobile systems and are responsible for producing electricity and creating motor power. Robotic Engineers, Electromagnets are commonly used in all kinds of robotic devices. The electromagnets create an electric current to power the robotics to make the motor spin and cause the robot to move. MRI Technicians, Electromagnets are used in magnetic resonance imaging (MRI) machines to create a magnetic field around a patient and look inside a patient’s body. The magnetic forces send radio waves throughout a patient’s body and create pictures of the tissues.
Outline 6 control measures that may be implemented to reduce the effects of exposure to ionising radiation
Reduce time of exposure
Put distance between person and source
Shielding
Training and education
Procedures for standard operation and emergency
Strict adherence with rules for personal protection
Radiation - The Role of the Competent Person
Radiation protection supervisor
A member of an organisations management team who ensures compliance with the requirements of the rules and procedures relating to ionising radiation in the workplace.
Radiation protection advisor
A qualified and competent person who acts in the capacity of expert to companies. Gives advice and guidance of application of legislation and assists in setting up rules and procedures relating to ionising radiation in the workplace.
Outline six possible causes of increased stress amongst workers
- Demands
When identifying the sources of stress it is important to consider the demands if the work activities/tasks. This includes the workload and work patterns and the work environment.
- Control
If employees have little or no control of the work that has to be done and how it should be done, this will be a source of stress.
- Support
Employees who do not feel supported and an organisation that does not provide training or adequate resources, a feeling of remoteness will be created.
- Relationships
Poor working relationships such as bullying may create additional stress.
- Role
If employees do not understand their role within the organisation or have conflicting roles this may increase the potential for stress.
- Change
If the management of organisational change is not committed or conducted well, employees may become stressed.
Typical effects of stress on workers
Physical Effects:
Loss or increase in appetite Inability to sleep Poor sleep patterns Constant tiredness Dizziness or blurred vision Headaches and backache Indigestion or nausea Constipation or diarrhea Sweating or trembling Increased blood pressure Heart disease Stomach ulcers Raised heart rate Skin rashes Aching neck and shoulders Prone to infections
Psychological Effects
Depression Irritability Low self esteem and negative thoughts Apathy and lethargy Inability to relax Restlessness Increased anxiety Resentment Tearfulness Irrational Fear
Behavioral Effects
Loss of interest and reduced concentration
Decision making problems
Poor work performance and missed deadlines
Short Tempered
Poor relationships with colleagues, family & friends
Increased use of alcohol
Increased smoking and may develop deeper dependency upon drugs such as prescription or over the counter preparations
Measures that can be taken to reduce the possibility of stress related illness
Selecting suitable employees Training Clearly defined roles Clearly work objectives Comfortable working environment Good lines of communication Realistic work schedules Employee involvement Grievance procedure Impartial investigation of stress
(a) Describe the possible effects on hearing from exposure to noise. [4 marks]
(b) Outline the factors that are likely to affect the performance of personal hearing protection.
For part (a), the possible effects that could have been described include temporary threshold shift which affects the ability to hear sound at particular frequencies, and is a condition which is reversible; permanent threshold shift where there is physiological damage to the sensory hair cells in the inner ear affecting sounds within the audible frequency range and particularly the speech frequency and which is irreversible; acoustic trauma such as a burst ear drum caused by exposure to a sudden loud noise; tinnitus, characterised by a ringing in the ears which may be acute or chronic; and occupational deafness where there is a significant loss of hearing.
As a “describe” question your answer needs to give some detail for each of the 4 effects. A simple list would not be credited with high marks.
In answering the second part of the question, you could have outlined a number of factors which could affect the performance of personal hearing protection such as incorrect selection; incompatibility with other personal protective equipment; incorrect or poor fitting by the wearer; incorrect attenuation and damage or lack of maintenance.
Hearing loss conditions are entirely preventable if:
(a) employers take action to reduce exposure to noise and provide personal hearing protection and health surveillance to employees;
(b) manufacturers design tools and machinery to operate more quietly; and
(c) employees make use of the personal hearing protection or other control measures supplied.
The process of assessing risks to health and safety due to noise exposure is in five stages:
Stage 1 Is there risk due to noise? Stage 2 Who might be harmed and how? Stage 3 Evaluate the risks and develop a plan to control them. Stage 4 Record the findings. Stage 5 Review the risk assessment.
The Noise Regulations give priority to the control of noise by technical or organisational means, as opposed to providing personal hearing protection because:
- noise control is usually the most cost-effective solution for the longer term;
- control of the noise risk at source protects a greater number of people in the surrounding working environment;
- personal hearing protectors protect only the individual wearer and do not always give the protection expected.
You should consider the methods of controlling noise in the following order:
- Can risks be eliminated by doing the work in a different way, eliminating or minimising exposure to noise?
- Can the work, process or machine be modified to reduce noise emissions?
- Is it possible to replace the tools and equipment used with lower noise alternatives?
- Can the workplace and workflow be arranged to separate people from the noise?
- Can the noise reaching people be reduced by controlling it on its path from the source?
The most important things to
remember about hearing protection:
• Hearing protection is a last resort but must be
used until noise risks are under control.
• Choose the correct level of protection.
This will not usually be the highest available.
• Make sure it is suitable for the user and their
work activities, and that they can use it
comfortably with any other PPE or equipment
they have to wear or use.
• Ensure they wear it at all times in the noisy area.
If they remove it, even briefly, they will have
wasted most of the time they have spent wearing
it. For example, removing protection for just 5
minutes out of one hour will reduce the protection
achieved by more than half.
How can we protect our hearing
on an everyday basis?
• Don’t stick dirty objects in our ears
• Turn down the volume of what we listen to
• Reduce the noise level or be further away
from it
• Reduce the length of time you are in the
noisy area
• Buy quiet - find low noise models when replacing
or hiring machinery
• Wear hearing protection to reduce the noise
level at the ear
If I can’t reduce the noise levels further,
what do I do about hearing protection?
Find suitable types of hearing protection
Earmuffs
They should totally cover your ears, fit tightly and have no gaps around the seals. Don’t let hair, jewellery, glasses, hats etc interfere with the seal. Keep the seals and the insides clean. Don’t stretch the headband – the tension is crucial to protection. Helmet-mounted earmuffs can need particular care to get a good seal around your ears.
Earplugs
They go right in the ear canal, not just across it. Practise fitting them and get help if you are having trouble. Clean your hands before you fit earplugs, and don’t share them. Some types you use only once, others can be re-used and even washed – make sure you know which type you have.
Semi-inserts/canal caps
These are held in or across the ear canal by a band, usually plastic. Check for a good seal, every time you put them on. Follow the same general advice as for earplugs and make sure any band keeps its tension.
The Control of Noise at Work Regulations 2005 (the ‘Noise Regulations’) require you to eliminate or reduce risks to health and safety from noise at work.
Depending on the level of risk, you should:
■ take action to reduce the noise exposure; and also
■ provide your employees with personal hearing protection.
Other duties under the Regulations include the need to:
■ make sure the legal limits on noise exposure are not exceeded;
■ maintain and ensure the use of equipment you provide to control noise risks;
■ provide your employees with information, instruction and training; and
■carry out health surveillance (monitor workers’ hearing ability).
You will probably need to do something about the noise if any of the following apply:
- the noise is intrusive – for example, as noisy as a busy road, a vacuum cleaner or a crowded restaurant – or worse than intrusive, for most of the working day;
- your employees have to raise their voices to carry out a normal conversation when about 2m apart for at least part of the day;
- your employees use noisy powered tools or machinery for more than half an hour each day;
- your sector is one known to have noisy tasks, eg construction, demolition or road repair; woodworking; plastics processing; engineering; textile manufacture; general fabrication; forging or stamping; paper or board making; canning or bottling; foundries; waste and recycling;
- there are noises due to impacts (such as hammering, drop forging, pneumatic impact tools etc), explosive sources such as cartridge-operated tools or detonators, or guns.
A risk assessment means more than just taking measurements of noise – measurements may not even be necessary. Your risk assessment should:
- identify where there may be a risk from noise and who is likely to be affected, include:
risks to health; and
risks to safety;
- contain an estimate of your employees’ exposures to noise (see ‘Noise exposure levels’);
- identify what you need to do to comply with the law, eg whether noise-control measures and/or personal hearing protection are needed, or whether working practices are safe; and
- identify any employees who need to be provided with health surveillance and whether any are at particular risk.
You must record the findings of your risk assessment. You must also record the action you have taken, or intend to take, to comply with the law.
How can I control noise?
First think about how to remove the source of noise altogether – for example, housing a noisy machine where it cannot be heard by workers. If that is not possible, investigate:
- using quieter equipment or a different, quieter process;
- engineering/technical controls to reduce, at source, the noise produced by a machine or process;
- using screens, barriers, enclosures and absorbent materials to reduce the noise on its path to the people exposed;
- designing and laying out the workplace to create quiet workstations;
- improved working techniques to reduce noise levels;
- limiting the time people spend in noisy areas.
Measures that give ongoing or medium- and long-term benefits, and would be expected to be part of your noise-control programme, are:
- a low-noise purchasing policy for machinery and equipment;
- proper and regular maintenance of machinery and equipment that takes ■■account of noise.
To comply with the exposure limits you must ensure that your workers’ noise exposure, reduced by an appropriate factor if they are using personal hearing protection, is not above:
- 87 decibels for daily or weekly personal noise exposure (LEP,d or LEP,w); and
- 140 decibels for peak sound pressure (LCpeak).
Hearing protection should be issued to employees:
- where extra protection is needed above what has been achieved using noise control;
- as a short-term measure while other methods of controlling noise are being developed.
You should not use hearing protection as an alternative to controlling noise by technical and organisational means.
Providing hearing protectors and managing their use
The Noise Regulations require you to:
- provide employees with hearing protectors and make sure they use them fully and properly when their noise exposure exceeds the upper exposure action values;
- provide employees with hearing protectors if they ask for them, and their noise exposure is between the lower and upper exposure action values;
- identify hearing protection zones – areas of the workplace where access is restricted, and where wearing hearing protection is compulsory.
To make sure protectors are worn fully (all of the time they are needed) and properly (fitted or inserted correctly) will require you to have systems of supervision and training. Also consider the use of spot checks and audits.
You should take account of the following in selecting the hearing protectors you provide to your workers:
- choose a suitable protection factor – sufficient to eliminate risks from noise but not so much protection that wearers become isolated;
- consider the work and working environment, eg physical activity, comfort and hygiene;
- compatibility with other protective equipment, eg hard hats, masks and eye protection.
You should only supply CE-marked hearing protectors. You must consult with workers and their representatives over the types of protector provided.
Explain the meaning of the following terms in relation to noise control:
a) Silencing
b) Absorption
c) Damping
d) Isolation
a) Silencing
Pies and boxes can be designed to reduce air / gas noise such as exhaust silencers.
b) Absorption
The surrounding structure is lined with sound absorbing materials such as foam or sound absorbing screens are placed around the noise sources. This enables the noise energy to pass into the absorbing structures where some of its energy is reduced.
c) Damping
The use of rubber mounts at the base of a machine can dampen the vibration and reduce a noise radiating through a structure from the vibration source.
d) Isolation
Total enclosure of the noise source through the purpose built structures or use of specially designed noise booths isolates the source from all other building users.
In relation to noise exposures, explain the following terms:
a) Frequency
b) Decibel (db)
c) ‘A’ weighting
a) Frequency
Frequency is the speed of the vibration, and this determines the pitch of the sound. It is only useful or meaningful for musical sounds, where there is a strongly regular waveform. Frequency is measured as the number of wave cycles that occur in one second. The unit of frequency measurement is Hertz (Hz for short).
b) Decibel (db)
Sound is measured in units called decibels. Sounds of less than 75 decibels, even after long exposure, are unlikely to cause hearing loss. However, long or repeated exposure to sounds at or above 85 decibels can cause hearing loss. The louder the sound, the shorter the amount of time it takes for NIHL to happen.
c) ‘A’ weighting
Noise is measured in decibels (dB). An ‘A-weighting’ sometimes written as ‘dB(A)’, is used to measure average noise levels
Identify the health effects associated with exposure to vibration
- Back disorders
- Osteoarthritis
- Abdominal pain, digestive, urinary disorders
- Interference with blood circulation
Outline the control measures that may be used to minimise the risk of such effects (vibration)
The main vibration control measures are provided below:
- Select equipment with low vibration output.
- Select ergonomically designed equipment which provides additional hand holds and reduces the grip level needed to remain in control of the equipment
- Develop a good maintenance regime for all plant and tools
- Introduce a work pattern for employees that reduces the time exposure of employees
- Ensure the work patterns allow for regular rest periods / breaks;
Introduce an appropriate health surveillance programme
Issue employees with gloves and heated pads to keep hands warm
Provide comprehensible information and training on the nature of the risk.
The Vibration Regulations require that you make a ‘suitable and sufficient’ assessment of the risks from vibration. This will include:
- identifying employees who may be at risk from exposure to HAV;
- soundly based estimate of your employees’ vibration exposures compared with the exposure action value and exposure limit value;
- the available and appropriate options for controlling risk;
- the steps you plan to take to control and monitor those risks as required by the Vibration Regulations (regulations 6, 7 and 8); and a record of:
- the assessment;
- the person(s) responsible for the assessment;
- the control measures you have taken and their effectiveness; and
- your plans for further action.
Users of the types of equipment listed below and similar equipment will often be exposed above the EAV:
chainsaws;
grinders (all types and sizes, eg angle, die, straight, vertical etc);
hand-fed equipment, eg pedestal linishers, grinders, mops;
impact drills;
scaling hammers including needle scalers;
pedestrian controlled equipment including mowers, floor saws, floor polishers;
powered hammers for chipping, demolition, road breaking etc;
sanders and polishers;
hand-held saws for concrete, metal, ground clearance etc.
Whole-body vibration
The regulations introduce an exposure value:
Exposure action value of 0.5 m/s2 A(8) at which level employers should introduce technical and organisational measures to reduce exposure.
Exposure limit value of 1.15 m/s2 A(8) which should not be exceeded.
Who is likely to have high exposures to whole-body vibration?
■ construction, mining and quarrying machines and vehicles, particularly earthmoving machines such as scrapers, bulldozers and building site dumpers;
■ tractors and other agricultural and forestry machinery, particularly when used in
transportation, tedding (turning hay), primary cultivation and mowing.
High exposures could occur where vehicles designed for smooth surfaces are driven on poor surfaces, eg when lift trucks with no wheel suspension or with solid
tyres are used on a cracked or uneven yard. Poor operating or driving technique with most off-road machines or vehicles (eg driving too fast) can also lead to higher exposures which can be reduced by good driver training and instruction. High exposures also occur in small, fast boats.
What can cause or aggravate back pain in mobile machine operators and
drivers?
Reasons for back pain in drivers can include:
■ poor design of controls, making it difficult for the driver to operate the machine
or vehicle easily or to see properly without twisting or stretching;
■ incorrect adjustment by the driver of the seat position and hand and foot
controls, so that it is necessary to continually twist, bend, lean and stretch to
operate the machine;
■ sitting for long periods without being able to change position;
■ poor driver posture;
■ repeated manual handling and lifting of loads by the driver;
■ excessive exposure to whole-body vibration, particularly to shocks and jolts;
■ repeatedly climbing into or jumping down from a high cab or one which is difficult to get in and out of.
The risk increases where the driver or operator is exposed to two or more of these
factors together
Vibration - What do I do about health monitoring?
HSE recommends that you set up a simple system of health monitoring for your employees whose jobs carry a higher than average risk of back pain.
You should:
■ agree with your employees and safety or employee representatives an ongoing system for early reporting of back pain symptoms;
■ review and analyse the results to identify vulnerable individuals and groups of workers;
■ periodically (HSE recommends once a year) complete a questionnaire checklist for employees at risk (an example questionnaire is provided on the MSD back pain website www.hse.gov.uk/msd);
■ refer employees with back problems to your occupational health service provider, where available;
■ treat personal information about the health of individual employees as confidential;
■ consider the results to check if your risk controls are working;
■ make changes to your risk controls if necessary
Outline the ways in which exposure to ionising radiation at work may be controlled
These controls include:
- Improved underfloor and indoor ventilation
- Sealing large gaps in floors and walls in contact with the ground
- Installation of radon sumps and extraction pipework
The prevention strategy with regard to exposure to occupational stress should include the following:
- the development of an organisational stress policy
- the inclusion of the risk of occupational stress in organisational risk assessments
- training and awareness for manager and staff with regards to recognition of the stress, problems, possible ill health effects and both personal and organisational risk controls
- the provision of support and counselling services for employees
- the development of a process which provides employees with the opportunity to have a say about the way their work is undertaken
- the development of organisational change management procedures which ensure that employees (including managers) understand the reason for proposed changes and that employees receive adequate communication during the change process.
Acute & Chronic effects of exposure to ionising radiation
Acute
Reddening of the skin
Radiation sickness - nausea, vomiting, diarrhea
Hair loss
Death
Chronic
Cancers such as leukemia
Sterility
Hereditary defects passed on to the future generation
Effects on unborn children
Other effects - skin and eye damage and death
Controlling exposure to radon
- improved underfloor and indoor ventilation
- sealing large gaps in floors and walls in contact with the ground
- installation of radon sumps and extraction pipework
Basic radiation protection strategies
- application of the principles of shielding, distance & time or a combination of all three
- emergency arrangements
- training of employees
- the prohibition of eating, drinking and smoking in exposed areas
- good standards of personal hygiene
- medical surveillance of employees
- strict use of RPE and PPE identified in the risk assessment process.
Radiation - the role of monitoring and health surveillance
The employer should provide health surveillance for workers who are exposed to ionising radiation.
The analysis of badge samples will be checked against exposure limits. In addition the general health of workers will be checked.
The aim of health surveillance is to ensure that no workers are exposed above the set limited and that any health effects are identified and controlled.
Stress - adverse consequences to organisations
- reduced performance and productivity
- increased absenteeism and sick leave
- increased errors and working practices compromised
- early retirement on the grounds of ill health
- poor decision making
- increased accidents and incidents
- job dissatisfaction
- threats and sabotage
- high staff turnover and intention to leave
