Guida generale alla sicurezza e al comfort

The use of a computer, a notebook, a tablet or video terminals involves a set of decisions that can affect both comfort and health and productivity. It is therefore important to pay attention to the posture and in any case, to adapt the position of the body according to the device. There is no "correct" position suitable for everyone and for all activities.

(Taken from the documentation of the Prevention and Protection Services of the University of Padua and the University of Udine)
Work at the display screen can pose a health hazard in relation to the characteristics of the workplace and the environment, the duration of exposure, the characteristics of the work performed as well as those of the hardware and software.

The disturbances that can be found can be:

  • visual disturbances essentially due to high stress and eye fatigue;
  • pains in the neck and joints due to incorrect postures held during the activity or deriving from the non-ergonomic workstation;
  • psychophysical stress due to the use of inappropriate software or an excessive workload.

Find the most comfortable position: avoid unnatural positions and make all possible adjustments to obtain a comfortable position.

FEATURES OF THE MONITOR

The video terminal screen must have the following characteristics:

  • dimensions suitable for the activity it is required to carry out and such as to be legible at 68: 80 cm;
  • radius of curvature, such as to minimize the possibility of light reflections deriving from the environment;
  • surrounding. The monitor must be positioned in such a way as to have the external and internal light sources neither in front of nor behind the operator;
  • adjustable contrast and brightness;
  • stable images;
  • defined and legible characters: the brightness and / or contrast between characters and screen background must be easily adjustable at the operator's will;
  • easily adjustable and tiltable;
  • must be placed in front of you to avoid twisting of the neck and back;
  • the top edge of the screen must be at eye level;
  • those who use bifocal lenses, try to position the screen lower to avoid neck tension.

WORKSTATION

The keyboard must be:

  • as flat, autonomous and mobile as possible;
  • with matte surface;
  • tiltable;
  • the space on the table in front of it must allow comfortable support for the hands and forearms;
  • the keys should have a concave surface to allow for easy compression; have an easily legible wording, written in a positive way (dark characters on a light background);

The desk that must have:

  • clear and non-reflective surface;
  • adjustable height of the top, if fixed from 68 to 82 cm from the floor;
  • dimensions of the top suitable for a correct and flexible arrangement of the monitor, keyboard and work documents;
  • the depth under the top must allow for the semi-extended legs;

The chair must be:

  • swivel;
  • adjustable in height and with the possibility of bringing it closer to the table;
  • dimensions not less than 40 by 40 cm, slightly concave and inclined forward by about 2 ° and backwards by 14 ° with respect to the horizontal and with the front edge rounded;
  • backrest, moderately shaped in the upper part, with the possibility of adjusting the depth, height and inclination and with further padding, to support the lumbar region;
  • without armrests or with short armrests;
  • covered with a soft and easily interchangeable surface;
  • with easy-to-handle and accessible controls in a sitting position.

The accessories

  • The document holder: for those who wish it must be adjustable and stable and at the same height and angle as the monitor.
  • The footrest: for those who want it, it must be stable and wide to allow the legs different positions.
  • The monitor stand: must be solid and easily adjustable.
  • The table lamp: it must be adjustable, shielded.

The work environment must have:

  • sufficient workspace for changes in position;
  • non-reflective light-colored walls;
  • climatic comfort, which assumes winter air temperatures above 18 ° C and summer temperatures no more than 7 ° C below those outside.
  • The workplace must not be subject to drafts produced by inlets, door and window openings, etc.
  • adequate air changes
  • low ambient noise.

The room lighting must be:

  • sufficient. The windows preferably located on one side only, preferably facing north, must represent 1/8 of the floor plan of the room
  • windows must be screenable, possibly with Venetian blinds or heavy fabric curtains.
  • Uniform, avoiding glare, reflections and flickering on the screen. If there are reflections, tilt the monitor or reduce the general brightness;
  • The light sources must be perpendicular to the screen, they must diffuse white-neutral light with a warm tone.
  • The workplace must be at least 1m away from windows.

PREVENTION MEASURES

And good practice every 20 minutes, observe distant objects to change the eye focus point.

To avoid visual fatigue it is useful to implement the following precautions:

  • position the monitor correctly with respect to light sources, so as to avoid reflections;
  • use any fixed or mobile screens to control natural light sources (curtains, Venetian blinds, etc.);
  • adjust the brightness and contrast of the screen in order to make the image clear and avoid excessive contrasts between the background of the monitor and the background of the room;
  • in case of visual fatigue, perform eye relaxation exercises;

To avoid disorders of the musculoskeletal system it is useful to implement the following precautions:

  • use ergonomic seats and maintain correct postures;
  • position the keyboard so as to rest the terminal part of the forearm on the work surface, or on the armrests of the seat, while typing;
  • in case of fatigue change position or perform relaxation exercises.

In any case, for those who work continuously at the VDU, it is prescribed to take breaks of fifteen minutes every two hours of work, dedicating themselves to other activities, especially avoiding sitting down.

HEALTH SURVEILLANCE

Employees of VDT use must be subjected to mandatory health surveillance, as indicated in art. 176 of Legislative Decree 81/08, with particular reference to:

  • the risks to sight and eyes;
  • the risks for the musculoskeletal system.

Following these investigations, the competent doctor expresses a judgment which may be of:

  • eligibility;
  • partial, temporary or permanent eligibility, with prescriptions or limitations;
  • temporary unfitness;
  • permanent unfitness.

Except for special cases that require a different frequency established by the competent doctor, the frequency of the check-ups is:

  • two years for workers classified as suitable with prescriptions or limitations, two years for workers who have reached the age of 50;
  • five years in the other cases.
  • In addition, for cases of temporary unfitness, the competent doctor establishes the deadline for the subsequent fitness visit.

The worker can also be subjected to a control visit for the risks indicated above at his simple request if "it is considered by the competent doctor to be related to professional risks or to his health conditions, susceptible to worsening due to the work performed, in order to to express the judgment of suitability for the specific job ". If the outcome of medical examinations highlights the need and it is not possible to use normal correction devices, workers will be provided, at the expense of the Employer, with special correction devices visual, depending on the activity performed.

The workers assigned to the video terminals must then be subjected to periodic health surveillance, to assess the possible appearance of oculofacial or general alterations referable to the work with the video terminals. These health protection measures apply exclusively to workers who are "screen workers", that is, those who use the screen systematically and habitually for at least 20 hours a week, less the breaks prescribed by law (15 minutes each 2 hours of uninterrupted activity).

However, at any time, every worker can request to be subjected to a control visit, if he accuses visual or musculoskeletal disorders, which could be linked to the use of the video terminal.

PREGNANT WORKERS

The risk assessment must also take into account movements, work positions, mental and physical fatigue and other physical and mental discomforts associated with the activity carried out while using the VDT by pregnant workers.
The only problem for pregnant workers is linked to the assumption of postural variations related to pregnancy that could favor the onset of back-lumbar disorders capable of justifying the temporary modification of conditions or working hours. In fact, specialist studies have shown that work at the VDT does not involve particular risks or problems for the worker or the unborn child.

Therefore, following the aforementioned assessment, the prevention and protection measures to be adopted are identified, such as:

  • greater rest breaks (15 minutes every 60 minutes of work at the VDT) in order to allow postural changes to prevent the possible onset of back-lumbar disorders.
  • modification of work rhythms, so that they are not excessive and that they do not involve a particularly tiring position for the worker.
  • If requested by the competent doctor, a temporary change in conditions or working hours will be arranged.
  • The workers assigned to the VDT and the workers' safety representative must be informed about the results of the assessment and the consequent measures adopted.

ELECTRICAL SAFETY MEASURES

  • Any tampering with the electrical system and any unauthorized intervention is absolutely prohibited.
  • Never disassemble the PC and do not open the container to carry out repairs or anything else .
  • For any interventions (expansions, change of cards, etc.) it will be necessary to contact the staff assigned to this or technical assistance.
  • Do not remove the plug from the socket by pulling the wire: the cable or the plug casing could break, making live parts accessible.
  • If the plug does not come out, avoid pulling with excessive force, as this could tear the plug from the wall.
  • When a plug breaks, it must be replaced by a qualified technician with a new one marked IMQ (Italian Institute of Quality Mark).
  • Do not plug more than one electrical appliance into a single outlet. This prevents the socket from overheating with the risk of a short circuit and fire.
  • Situations where multiple adapters are installed, one on top of the other, are expressly prohibited.
  • If indispensable (and with the authorization of the Safety Manager), always use adapters and extensions suitable for withstanding the current absorbed by the user devices.
  • All sockets and power strips show the current indication, in Ampere (A), or the maximum power, in Watts (W).
  • German type plugs (Schuko) can be inserted into Italian type sockets only by means of an adapter which transfers the earth connection made by means of the lateral plates to a central plug.
  • The insertion of Schuko plugs into Italian type sockets by force is strictly prohibited. In fact, in this case the earth connection would be excluded.

REGULATORY SOURCES

Work at the VDT is considered a risky activity for the health and safety of workers, and as such is regulated within the Consolidated Law on Health and Safety at Work (Legislative Decree 81/08), amended by Legislative Decree 106/09. The contents of Legislative Decree 81/08 incorporate, with some modifications, what is already present in Legislative Decree 626/94 (and subsequent amendments including L 422/00), which incorporated a series of European Directives on various issues relating to safety at work.

INAIL: Prevention and safety -> Knowing the risk -> Ergonomics -> Video terminals
Read the INAIL documentation

Author: Loris Modena

SENIOR DEVELOPER

For Ind Loris Modena , owner of Arte e Informatica , he began working in the IT sector in 1989 as a system engineer in charge of the maintenance and installation of IT systems. He started programming for the web in 1997 dealing with CGI programming in PERL and then moving on to programming in PHP and JavaScript. In this period he approaches the Open source world and the management of Linux servers.

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