Health & Safety at Work

Safety Note 10.3

DISPLAY SCREEN EQUIPMENT

Health and Safety Information

and Guidance for Users

SCM/ACH C:\VDU\UsersNotes’Jun’2010\RevJan2012 June 2010; Rev January 2012

March 1998

INDEX

Page

1. Introduction 1

2. The risks 1

3. Analysis of workstations 1

4. Measures you can take to reduce any risk 1

4.1 Posture 1

4.2 Screen legibility 3

4.3 Organisation of your work and workstation 3

4.4 Use of a mouse 4

4.5 Use of a portable computer 4

5. Eye tests for Users 5

6. Reporting of ill-health problems 5

7. Pregnancy and DSE work 5

8. Daily reminder 6

Appendix: Possible effects on health 7

1

1. INTRODUCTIONLegislation covering the use of display screen equipment was introduced on 1st January 1993, namely the Health and Safety (Display Screen Equipment) Regulations 1992 as amended by the Health and Safety (Miscellaneous Amendments) Regulations 2002. The aim of the Regulations is to ensure that employers and employees take the appropriate action to control any risks associated with the use of such equipment, the most familiar of which is the personal computer used for applications such as word processing.

2. THE RISKSThe principal risks relate to musculo-skeletal problems, visual fatigue and mental stress. It is known that long hours of intense work with badly designed equipment can sometimes cause one or more of these problems in a minority of users. Problems such as eye-strain are short-term in nature and are unlikely to have continuing consequences for long after the work has ceased. However, musculo-skeletal problems caused by rapidly repeated keying or bad posture, for example, can have long-term effects and may be difficult to rectify even if working methods are changed or the work ceases. There is more detailed information about possible health effects later in this document.

3. ANALYSIS OF WORKSTATIONSA workstation is defined as the display screen equipment itself, the accompanying disk drive, printer, desk, chair, document holder, telephone, etc. and the immediate work environment. Your workstation and work practices must be analysed to assess the risks involved with the work. Each department have their own DSE assessors and they will carry out an assessment of your workstation . This should be within the first three months of starting work. In the meantime you are advised to follow this link to ensure you have adjusted your work station correctly http://www.learninglink.ac.uk/site.htm .

If the assessment shows that changes to the workstation or work practices are required to reduce any risk, then the appropriate remedial action must be taken. This might be action by you or by your departmental management.

4. MEASURES YOU CAN TAKE TO REDUCE ANY RISKProblems related to display screen work are usually the result of poor working practices over a considerable period of time. Following simple rules about the set-up of your workstation and the organisation of your working day is often sufficient to prevent any ill-health effects.

4.1 Posture

There is no such thing as an "ideal posture" but sitting upright with the lower back supported and the feet resting on a firm surface will help reduce the possibility of muscle tiredness; changing your position regularly will also help because sitting still for long periods is undesirable, no matter how well-designed your workstation might be.

Work through the following steps to optimise your set-up; reference to the diagram should be of help.

(i) Adjust the height of your seat so that your forearms are roughly horizontal and your wrists are straight when your hands are on the home keys. Working in this position, with your elbows kept close to your body, minimises the risk of discomfort in your wrists, arms, shoulders, neck or back. Many workers find a wrist rest placed in front of the keyboard helpful; a wrist rest can also be helpful when a lot of mouse work is carried out. If your feet are not comfortably on the floor or there is pressure on the back of your thighs from the seat edge, use a foot rest or improvise one.

(ii) Adjust the position of your backrest so that it supports your lower back. Use it properly by sitting right back in the chair - avoid slouching or sitting on the edge of the seat.

2

(iii) Adjust the position of your screen to avoid neck and shoulder pains caused by viewing at the wrong angle. Usually, the most comfortable position is looking down at the screen at an angle of about 15 degrees. This angle can be achieved by making sure the top of the monitor is level with your eyes. You may need to remove the monitor from the top of the processor or, alternatively, raise it to obtain the best viewing angle for you.

(iv) Remove obstacles from underneath your desk so that you can sit upright.

(v) If you are working from a hard copy, use a document holder to avoid having to lean forward to read the text.

3

4.2 Screen legibility

One of the causes of tired eyes and headaches at the end of the working day is difficulty in reading the screen. Apart from problems with your vision (see section 5), this could be due to a number of factors such as reflections on the screen, inadequate contrast on the screen between characters and background, and poor lighting. Use the following advice to reduce the likelihood of problems developing.

(i) Arrange your monitor so that it is at the correct viewing distance for you (this is usually between about 40 and 60cm from the eyes Approximately an arms length.). As your eyes tire through the day, you might find it beneficial to re-adjust the screen position.

(ii) Check for reflections on the screen from the window and overhead lights and adjust the screen angle and position if necessary to remove them. N.B. This checking is easiest if carried out with the monitor turned off.

(iii) If possible, sit with the screen at right angles to the window.

(iv) Adjust the brightness and contrast controls to optimise the display. If necessary, re-adjust during the day as the lighting conditions change. If the artificial lighting levels are too high, try selectively turning off lights but you might then need local desk lighting for your hard copy. Use window blinds or curtains if they are available to reduce unwanted natural light.

(v) Keep the screen clean with a proprietary cleaner

4.3 Organisation of your work and workstation

(i) Aches and pains are more likely if your workstation is arranged so that you are forced to adopt a poor posture even after correctly adjusting your chair. Arrange your workstation so that you do not have to twist or bend unnecessarily. Keep your work area free from clutter but have within easy reach those things you use frequently.

(ii) Use a document holder close to your monitor and adjust it to match the screen height. This will prevent constant re-focusing of the eyes between the screen and document and hence reduce the likelihood of eye-strain. It will also reduce repeated head and neck movements which might cause muscle ache and pain.

(iii) Organise your work so that spells at the screen are interspersed with other jobs, if possible; leave the screen before you feel tired.

(iv) If your job consists only or predominantly of screen work, you will need to take periodic breaks to prevent fatigue. Short, frequent breaks away from the screen and before you become tired, will be more beneficial than occasional, longer breaks. You should discuss this with your manager/supervisor (if appropriate).

(v) During your work breaks, get out of your seat and stretch and relax your limbs and back. Relax your eyes by looking into the distance. If you have spent a long period at the screen, avoid activities that involve hand and wrist movements and don't read fine print if your eyes feel tired.

4

Workspace layout guidelines

Items most frequently used should be placed in the optimum to maximum reach sector (see diagram below) to ensure that excessive reaching or stretching is avoided.

4.4 Use of a mouse

Mouse work, because it concentrates activity on one hand and arm, may cause aches and pains in your fingers, hands, wrists, arms of shoulders. Some people find that using a mouse-substitute such as a trackball or a pressure-sensitive pad is beneficial in relieving such symptoms. Changing from right-handed to left-handed use (and vice-versa) may also be helpful as can using a differently shaped or sized mouse. Occupational Health holds a stock of mouse-substitutes which you may borrow for short trial periods.

The following basic advice should be noted:-

(i) Position the mouse or mouse-substitute within easy reach so that you do not have to work with your arm stretched. Move the keyboard out of the way, if possible.

(ii) Support your forearm on the desk or with an appropriate arm rest. Use a wrist rest if necessary to keep your wrist straight.

(iii) Don't grip the mouse too tightly and keep the action of your fingers as light as possible.

(iv) During short pauses in mouse use, let your arm hang straight down.

4.5 Use of Laptop computers

Because of its smaller screen and keyboard, a laptop is less comfortable to use for prolonged periods than a normal desk top computer. All staff should be provided with a basic desk top computer for daily use.

Maximum Reach Sector

Outer Reach Sector

Optimum Reach Sector

5

When a laptop is used the advice given above about sitting comfortably, minimising reflections on the screen and taking frequent breaks if the work is prolonged should be followed. See Guidance for the use of laptops.

The use of laptops for prolonged periods is discouraged unless they are set up in a docking station, with a separate keyboard and mouse and comply with all the ergonomic principles of a normal desk top computer to minimise the risks of adverse health effects.

5. EYE TESTS FOR USERSThose members of staff who use display screen equipment habitually for a considerable portion of their working time and have little or no discretion over its use are legally defined as "Users". Such Users are entitled to request a free eyesight test and will be issued with a voucher that can be exchanged for an eyesight test and basic NHS lenses and frame. Eyesight testing voucher procedure - Staff.

Users are advised to check what arrangements have been made for requesting tests and the provision of eyesight test vouchers.

6. REPORTING OF ILL-HEALTH PROBLEMS

It is very important that you report any signs of ill-health connected with your work as promptly as possible so that action can be taken to prevent the effects becoming serious or permanent. These should be reported to your Display Equipment Assessor and a fresh Display Screen Equipment assessment carried out. The Assessor should then report any corrections made to the work station and complete a work-related ill-health report form and forward to Occupational Health.

The indicators of possible problems are:

back pain

pins and needles or numbness in the hands or arms

persistent aches and pain in the hands, arms or shoulders

tired eyes or headaches

focusing difficulties or oversensitivity to light.

7. PREGNANCY AND DSE WORKIn the past, there have been worries that pregnant women who work with DSE are at an increased risk of miscarrying. A substantial study, however, has confirmed earlier research that even those who habitually use DSE are no more likely to have a spontaneous abortion than non-users.

It is known, however, that anxiety and stress can cause complications and anyone who is pregnant and concerned about her work should discuss it with her supervisor (if appropriate). The University Occupational Health Adviser is also available to give advice.

8. DAILY REMINDER

6

Is your seat at the correct height to keep your forearms horizontal and your wrists straight when your hands are on the keyboard?

Is your lower back comfortably supported by your chair?

Do you have sufficient leg room?

Are your feet comfortably supported on the floor or footrest?

If you need to use one, is your document holder correctly positioned and adjusted?

Have you adjusted brightness control to suit the lighting level?

Have you checked for, and removed if necessary by altering the angle of the screen, any reflections or glare?

Does your screen need cleaning?

Is your mouse or mouse-substitute positioned to allow you to work comfortably with it?

Remember to take a break from the screen to do other tasks or to have a short rest before your muscles get tired.

7

Appendix

The main hazardsMost health problems caused by display screen work reflect bodily fatigue, manifested by eye and musculo-skeletal problems. Proper attention to ergonomic factors in the design, selection and installation of equipment and the organisation of the work will prevent such problems developing.

Eye problemsMedical evidence has shown that work with a display screen does not cause damage to eyes or eyesight, nor does it aggravate any existing eye defect. However, like any other visually demanding task, such work may cause some people to suffer temporary visual fatigue. The symptoms of this include tiredness, red or sore eyes, headaches and difficulties in focusing.

Possible causes are:

(a) Concentrating on the screen for prolonged periods reduces the blink reflex . The blink reflex sweeps tears across the eye preventing them becoming dry and irritated.

(b) poor positioning of the display screen equipment;

(c) poor legibility of the screen or source documents;

(d) poor lighting, causing glare or reflections and

(e) a drifting, flickering or jittering image on the screen.

DSE work may make some people more aware of pre-existing vision defects; this could lead to eye-strain symptoms since uncorrected defects can make the work more tiring or stressful than otherwise would be the case.

Muscle and body painWork related upper limb disorders (WRULDs) have been associated with display screen equipment work. Several factors are likely to contribute to these problems, such as prolonged static posture of the back, neck and head, and awkward positioning of the hands or wrists as a result of poor working technique or inappropriate work height. It is also known that rapid repetitive movements of the fingers, hands and arms can result in upper limb symptoms such as discomfort, numbness, tingling or soreness in the hands and forearms, which should not ignored. The importance of prompt reporting of any problems is obvious.

Fatigue and stressost types of continuous and sustained work may lead to fatigue and stress, resulting in changes in mood (frustration, irritability, anxiety, etc.) or physiological disorders (muscle tension, stomach disorders, sweating, headaches, etc.). The most likely cause is poor job design or work organisation.

8

Other concernsRadiationAlthough display screen equipment emits electromagnetic radiation, extensive measurements have confirmed that the levels found from all makes of equipment are well below those set internationally to protect human health. The National Radiological Protection Board has therefore advised that such equipment poses no radiation risk to a user, including a pregnant one. Hence, no protective measures need to be taken by users.

Facial dermatitisSome DSE workers have reported skin complaints such as occasional itching or redness of the face and/or the neck. The problem seems to be caused by environmental factors such as a combination of a dry atmosphere and static electricity near the equipment. It is, however, a rare problem.

EpilepsyMost people with epilepsy are completely unaffected by DSE. A few who suffer from the rare photosensitive epilepsy may be affected in some circumstances. Anyone who has epilepsy and is concerned about display screen work should seek further advice from the University Occupational Health Adviser.

MedicationThe use of medication such as minor tranquillisers can occasionally produce side effects which mimic some of the symptoms of visual fatigue, such as the slowing of eye movements. However, there is no evidence of any interaction between any types of medication and the use of display screen equipment.

SCMMarch 1998/Rev June 2010/Rev January 2012