Working with computers, printers and telephones

Reading without adequate light or reading small print over long periods of time can cause eyestrain. Visual fatigue is not believed to contribute to the long-term deterioration of vision. Research also shows that using a computer does not cause permanent damage to eyes. However, uncorrected vision problems can:

• make computer use uncomfortable
• lead to blurred vision and eyestrain.

Eyestrain can cause:

• eye irritation
• watering and reddening of the eyelids
• blurred vision
• headaches, particularly if the head and neck muscles are held in a static position.

People concentrating on a computer screen tend to blink less. This can lead to their eyes drying out. This is made worse in a dry environment, such as a heated or air-conditioned office.

To minimise the risk of eyestrain, employees should:

• Take regular breaks.
• Look around at objects that are at different distances. Consider the 20-20-20 rule. Every 20 minutes, stop work and focus on an object 20 feet away for 20 seconds.
• Blink often.
• See an optometrist if problems persist. An eye test can identify and correct pre-existing visual defects that may cause discomfort when an employee is looking at a screen.

Many employees have difficulty with vision during close work because of a condition known as presbyopia. They may need prescription glasses for correction.

Bifocals are designed to correct vision when looking down through the lower portion of the lens for close work. This may be suitable for reading a document.

But when reading information on a screen, computer users generally look horizontally over the section of the lens designed to correct their vision. Many users lean forward and tilt their chins up to look through the lower part of the lens. This unnatural posture is unsatisfactory and can cause neck discomfort.

In these circumstances, employees may benefit from prescription glasses with full corrective or multifocal lenses. Any working documents should be placed between the screen and keyboard or alongside the screen to ensure the same focal distances for both. This reduces the likelihood of the operator adopting unnatural neck postures.

Computer users concerned about their vision or prescription glasses should seek advice from their medical specialist.

Some organisations have an agreement for vision testing for all computer users and provide a subsidy for prescription glasses.

More than 1% of Australians have epilepsy. Up to 5% of people with epilepsy have photosensitive epilepsy, which means flashing or flickering lights or certain shapes or patterns can trigger their seizures.

Computer screens are unlikely to trigger a seizure. However, if a person with epilepsy is starting a job involving office work, consideration should be given to the many factors that may aggravate this condition. If there is concern about flickering of a screen or lighting, a medical specialist should be consulted.

Employers must control the risk of musculoskeletal disorders (MSDs). This includes the risk of MSDs from typing. Employers should:

• provide resources and training to improve touch-typing skills where needed
• ensure employees' workstations and computers are set up correctly
• ensure that employees take regular breaks from typing.

Common hazards in office work

Users should tilt the keyboard using the feet at the back to suit their level of comfort. The common and preferred setting is to lower the feet so the keyboard sits flat on the desk. This helps prevent awkward wrist postures.

Place the keyboard as close to the front edge of the desk as is comfortable. For most users, this will be about 10–15 cm from the edge of the desk. Do not place documents between the keyboard and the front edge of the desk while using the keyboard. This can lead to poor working posture. Ensure there is room to put the keyboard to one side when it is not in use.

Employers should provide employees with the appropriate keyboard and instructions to carry out their work safely. Consider installing software that tracks keyboard use to prompt users to take a break.

Figure 7: Place the keyboard as close to the front edge of the desk as is comfortable

Modern optical mice don't need a mouse mat. If one is used, it should be directly beside the end of the keyboard on the user's preferred side. Use the mouse in this position and always aim to keep the mouse on the mat during use. Have the mouse as close to the centre in front of the user as possible.

If possible, use a mouse with either hand for improved comfort. Avoid holding the mouse when not in use.

Employers should provide employees with the appropriate mouse and instructions to carry out their work safely. Consider installing software that tracks mouse use to prompt users to take a break.

Checklist: Setting up a workstation and working with computers

Alternatives to the standard mouse change the hand and arm postures of users and can increase efficiency. Alternatives to the mouse include:

• roller bars
• stylus pens
• track balls
• pads
• glide points.

The main difference between a mouse and these devices is that the hand and arm remain stationary while the wrist is at an angle and the fingers or thumb stretch. Long periods of such use may cause finger, thumb or wrist discomfort. Users should lift their hand off the keys while operating the pointing device.

Figure 8: The top of the screen should be level with or slightly lower than the user's eyes when sitting upright

Computer screens should be adjusted after the user has established chair and desk heights.

Positioning the screen

• The top of the screen should be level with or slightly lower than the user's eyes when sitting upright. If the screen does not have a raising device such as a monitor stand, use another elevating device to temporarily raise the screen height.
• Place the screen so it is approximately an arm's length away from the user's usual seated position. Trial this position and move the screen further away or closer as required.
• Place the screen so it does not:
  • face windows
  • catch reflections or glare from windows or lights
  • have a window directly behind it causing glare.

Figure 9: Computer screens placed to reduce reflections

Using 2 or more computer screens

The use of 2 or more computer screens is common in offices. This allows users to run multiple applications and multitask to improve productivity.

Setting up multiple monitors requires the same approach as when setting up a single screen. It is important for the user to have a comfortable supported posture.

The following guidelines may help when setting up multiple monitors:

• Different viewing frequency: if using one monitor more frequently than the other:
  • place the primary monitor straight ahead to avoid twisting the body or neck to one side to view the display
  • move the chair when using secondary monitors to avoid bending or twisting to see the displays
  • adjust monitor height so the top of the monitor is at eye level or lower.
• Equal viewing frequency: if using multiple monitors with equal frequency:
  • position the screens next to each other
  • arrange the monitors in a slightly concave shape
  • position the screens at equal viewing distance from the user.
• Vertically stacked screens: if using monitors that are stacked vertically:
  • position the most frequently used display slightly below eye level.

Using different computers

If using a combination of computers such as a desktop monitor and a laptop computer:

• Place the laptop on a docking station or stand so the laptop display is at the same height as the desktop monitor.
• Place the laptop and desktop monitors at an equal viewing distance, particularly if the user is wearing reading glasses.

Other considerations

Other considerations when setting up multiple screens include:

• Adjusting the font size or display on each screen to be the same.
• Using a deeper desk to ensure:
  • there is adequate room at the workstation for the various monitors plus any other tasks such as writing
  • the monitors can be placed at a longer working distance to avoid having to turn the head and body to see the displays.
• Positioning less frequently viewed displays above eye level.

Using curved screens

Curved monitors have several benefits that flat screens do not. These include:

• They are more immersive – this is because they cover more of a user's peripheral vision.
• They are more comfortable for your eyes – they follow the natural curvature of the human field of view. This can reduce eyestrain from intensive work.
• They provide larger perceived images.
• There is less distortion of images than on a flat display.
• Users can have more applications and windows open at the same time.

Risks with using curved monitors include a greater risk of glare. For more information on how to reduce glare, see 'Glare in a work area' in Designing a healthy and safe working environment.

Designing a healthy and safe working environment

Curved monitors can be more expensive. They will also take up more space in a workstation.

Portable computers such as notebooks, laptops and tablets are designed for short-term or mobile use. Their portability means they are used in a wide variety of situations and settings where there is limited capacity to adjust the desk. This can result in problems including:

• Unsuitable work height.
• User discomfort: being unable to adjust the screen and keyboard can mean the user' arms are held too high or their neck is bent to view the screen frequently or for long periods.
• Reflections: if the screen is tilted upwards to reduce the need to bend the neck to view the screen.

These issues may be prevented by:

• docking the portable computer at an adjustable workstation
• connecting into existing computing equipment, such as a screen, keyboard and mouse
• transferring information to a desktop computer for more extensive periods of work
• keeping good posture when using the portable computer and frequently rotating between typing or keying and other activities
• not using the keyboard for long periods without a break.

Carrying portable computers may also contribute to back and neck problems.

Employees should avoid long-term use of a laptop computer on their lap because of possible thermal effects.

Wrist and forearm rests

Wrist or forearm rests are part of some keyboard designs. They support the forearm during pauses in typing and keyboard tasks. In practice, however, people often use them while typing. This causes the fingers to reach to the keys rather than the whole arm generating the movement. Typing with wrists on rest devices may:

• strain the wrist muscles and tendons
• increase sustained load on the shoulders and cause discomfort or muscular strain because the keyboard is further away from the user.

Wrist rests should not be needed if a workstation has been adjusted to meet the needs of the user.

Document holders

Employees often read documents lying on the surface of a desk for prolonged periods. This may lead to poor posture and cause neck and shoulder strains. Document holders are designed to position reference material according to the user's visual needs.

Upright movable document holders can be positioned next to the screen at the same height and visual distance from the user. A-frame or flat document holders can be positioned between the screen and keyboard to support multiple or bulky papers.

A-frames should be able to raise, lower and angle documents to different screen heights.

Monitor stands

Screens may need to be raised above desk height to reduce strain on the user's neck muscles. The top of the screen should generally be:

• level with the user's horizontal eye level
• approximately one full arm length away when the operator is sitting in their usual position for typing or keying.

A variety of stands are available to raise screens above desk height. Fixed-height stands tend to be suitable for single-user workstations where the:

• height of the monitor suits the individual's needs
• employee performs varied tasks, including typing or keying, throughout the day.

Adjustable-height and movable stands can be used to:

• meet the needs of different users
• provide space for other tasks.

Computer docking stations

Docking stations enable portable computers to be used in a variety of locations. They can easily connect the computer to other devices, such as a screen and full-size keyboard. This can improve the user's posture, actions and overall comfort.

The lamp used in photocopiers produces intense light. Exposure to this light is like a camera flash and may make it hard to see for a moment.

Continuous exposure to the bright light can lead to eye discomfort, although damage is unlikely. To reduce the risk of exposure to the photocopier light:

• close the cover when the copier is in use
• look away when the lamp is on
• locate copiers away from employees.

When used normally, the thick glass plate between the lamp and the operator screens out any harmful light, such as ultraviolet rays.

Photocopiers, printers and facsimile machines are often kept in one room or grouped in the same area. If there is a door, leave it open to avoid atmospheric contaminants building up to levels that may be a risk to the health of nearby employees. For open spaces, ensure there is adequate ventilation and air flow.

Assess the effect on ventilation and make other changes if:

• noise is a concern
• the door is closed for other reasons.

If ventilation is adequate, heat from standard equipment should not affect the office environment.

Toners have extremely low levels of impurities. This means there is a low risk of long-term health effects. Toner dust can enter the atmosphere during toner replacement or disposal of waste. If inhaled, the dust may irritate, causing coughing and sneezing. A copy of the safety data sheet (SDS) from the toner manufacturer will provide:

• the health and safety information needed to identify and assess any hazards
• handling and storage information.

Some photocopiers produce ozone gas. This unstable form of oxygen can become pungent at higher concentrations. When ozone levels increase, employees may experience:

• eye, lung, nose or throat irritation
• a prickly sensation.

The concentration of ozone around copying equipment is too small to cause any known harmful health effects.

For more information about ozone, see ‘Air quality in offices’ in Designing a healthy and safe working environment.

Designing a healthy and safe working environment

Laser printers can emit nanoparticles. These are particles between 1 and 100 nanometres, or about one thousandth the width of a human hair. The effects of inhaling nanoparticles are not well understood, but they can harm people and the environment due to their:

• size
• physical and chemical properties.

Employers should eliminate or reduce employee exposure by:

• keeping printers in ventilated areas away from workstations
• not grouping printers together
• regularly servicing and maintaining printers.

More information about nanoparticles and printers is available in Safe Work Australia's report Nanoparticles from printer emissions in workplace environments.

Employers can minimise the risk of working with copiers and printers by using these control measures:

When buying new equipment

• Choose machines that:
  • recycle toner
  • use sealed toner cartridges and waste containers
  • filter exhaust air
  • have automatic cut-off when the waste container is full or the machine is opened
  • prevent contact with live electrical components when clearing paper jams
  • eliminate manual tasks with automatic stapling, hole punching, collating and double-sided printing
  • have no exposed moving parts during normal operation.
• Buy toner with specifications that show minimal risks to health and safety.

When installing equipment

• Put equipment in an area that:
  • is well ventilated
  • provides the least disruption to nearby employees
  • does not obstruct aisles or building exits
  • has enough space around machines for operation and access for maintenance.
• Install equipment according to the manufacturer's specifications. Get the relevant:
  • operating diagrams
  • instruction manuals
  • SDS.

Store these documents near the equipment.

• Clearly display:
  • procedures to safely use the machine
  • the name of the person responsible for the machine.
• Consider the height and positioning of equipment and work surfaces. This will help to minimise the risk of MSDs.

When using and maintaining equipment

• Train users to:
  • Never look directly at the light from photocopiers. The document cover should be closed wherever possible when photocopying.
  • Follow manufacturer's instructions when clearing paper misfeeds. Beware of hot components.
  • Avoid continuous photocopying and collating. Schedule duties appropriately or allow for adequate breaks.
• Provide gloves for cleaning up any spilled toner. Dispose of waste toner as recommended by the manufacturer.
• Train specific employees in tasks like:
  • clearing paper jams
  • changing toner containers.
• Train all employees in general use of the equipment.
• Use authorised service personnel to regularly maintain all equipment to manufacturer specifications. Keep a register of maintenance, repairs and replacements.

Figure 10: Reducing risk by using a telephone headset

People at work use telephones to varying degrees. When using a telephone, employees should be able to do other simple tasks like taking notes without needing to:

• twist
• support the telephone on their shoulder.

Employees can usually put a telephone in a suitable spot if it:

• is cordless
• has a long cord.

Telephones should be cleaned regularly.

Employers should provide headsets to employees whose jobs involve:

• tasks like typing or taking orders while using a telephone or software-based phone
• dedicated telephone work, such as in a call centre.

Using a headset can help to:

• reduce how far and how often employees need to reach for the telephone
• eliminate awkward neck postures.

Wireless headsets allow employees who often use the telephone to change their posture and position.

Hazards from working with headsets include:

• loud unpleasant noises, also known as acoustic incidents
• illnesses from poor headset hygiene
• vocal fatigue.

Headset users may experience an unexpected or loud noise, known as an acoustic noise. Acoustic noises may be:

• crackles
• hisses
• whistles
• high-pitched sounds transmitted through telephone equipment.

The noises can come from a wide variety of sources. These can be either within the transmission system or from the customer end.

These occurrences, known as acoustic incidents, are quite common.

Acoustic shock

Occasionally, a headset user who has an acoustic incident may then develop neurophysiological and psychological symptoms. These are known as 'acoustic shock'. They can be temporary or permanent.

Research suggests a hypersensitive neurological reflex – the startle reflex – can cause acoustic shock. When a person is 'sensitised', they become more aware of an incident happening again. This fear may cause further noise hypersensitivity at noise levels sometimes well below standards for typical noise injuries.

It is likely that acoustic shock is not due to one single factor, such as the level of sound experienced. Rather, it is a combination of physical and psychological factors.

Other factors can also affect the symptoms. These include:

• middle-ear inflammation
• feelings of stress, tension and anxiety.

The same acoustic incident can affect individuals differently. Only a small minority develop symptoms from an acoustic incident. It is unclear why this is the case.

Audiologists have grouped acoustic shock into 3 categories.

1. Primary acoustic shock, which occurs immediately

Symptoms include:

• a feeling of fullness in the ear
• burning sensations or sharp pain around or in the ear
• numbness, tingling or soreness down the side of the face, neck or shoulder
• nausea or vomiting
• dizziness
• tinnitus and other head noises such as eardrum fluttering
• hearing loss in very few cases.

2. Secondary acoustic shock, which occurs later

Symptoms include:

• headaches
• fatigue
• a feeling of being off-balance
• anxiety.

3. Tertiary acoustic shock

Symptoms include:

• Hypersensitivity – a sensitivity to previously tolerated sounds. For example:
  • loud voices
  • television and radio.
• Hypervigilance – being overly alert.

Employees with these symptoms will respond in different ways. Some may also experience:

• anger
• anxiety
• social isolation
• other interrelated problems.

Very few people suffer hearing loss from acoustic incidents. To help diagnose any hearing loss, employers should consider asking an audiometrist to do baseline testing of new employees' hearing.

Managing acoustic incidents

To reduce the risk of acoustic incidents, employers should:

• assess the workplace environment
• use a range of controls.

Risk factors for acoustic incidents include:

• how many calls an employee receives or makes in a working day
• quality of handset or headset
• background noise levels
• volume of incoming sound levels
• unexpected increases in sound volume
• duration of calls
• frequency of sounds
• types of sounds
• individual characteristics such as health and wellbeing
• history of acoustic incidents.

Equipment should meet Australian standards and be of good quality. Consider:

• sound/call quality
• noise-cancelling functions
• headsets with acoustic shock protection
• dB limits
• comfort and fit.

For more information, see AS/CA S004:2013 Voice performance requirements for Customer Equipment.

To prevent the possible spread of infection, each employee should have their own headset. Headsets need to be cleaned regularly.

When buying a headset and deciding on the design and number of earpieces, employers should consider:

• the surrounding environment
• if employees need to attend to other signals.

A hands-free phone may be used for teleconferences but they are not suitable in an open-office environment.