Isolated work: how to prevent risks?

What is lone working and how is it regulated? What measures should be put in place? We take stock in this article.

Clara Godin
Environmental & occupational health & safety lawyer
Update : 
07.07.2026
Publication: 
22.07.2024

🔎 Things to remember

  • An aggravating risk factor: Working in isolation is characterized by the inability to be seen or heard directly and by the lack of immediate assistance in the event of an accident. Even if it lasts only a very short time, isolation drastically increases the severity of an incident.
  • Strict regulatory prohibitions: The Labor Code expressly prohibits working alone when performing certain highly dangerous tasks. It is therefore strictly prohibited to leave a worker alone while working at heights with a safety harness, working in confined spaces, or in hyperbaric environments.
  • The DATI, an Essential Safety Tool: To address the risks of working alone, employers must implement organizational and technical measures. This includes providing a Lone Worker Alarm System (DATI) capable of automatically detecting a fall or prolonged immobility (loss of upright posture).
  • A formalized emergency response chain: Safety is based on a strict procedure: activation of the DATI, a “verification” phase conducted by a designated monitoring station, followed by immediate contact with emergency services, including geolocation. Any failure to comply with this safety requirement subjects the employer to civil and criminal liability.
  • Isolated working is a necessity for many companies. Nevertheless, the isolation of workers is an aggravating risk factor in the event of an incident. What measures should be put in place? We take stock in this article.

    What is lone working?

    "Work is considered isolated when the worker is out of sight or within earshot of other people and without the possibility of outside recourse, and the work is of a dangerous nature."

    This extract from CPAM recommendation R416 serves as a definition of isolated work.

    Three characteristics define lone working:

    • inability to be seen or heard by other workers;
    • lack of outside help;
    • the hazardous nature of the work.

    ⚠️ Warning : Even short-term isolation must be considered as isolated work.

    Whether for practical or safety reasons, or because of the constraints of working conditions, many sectors of activity resort to isolated working, in particular :

    • hospitals ;
    • food processing ;
    • construction ;
    • maintenance ;
    • ...

    Note: According to the Institut national de recherche et de sécurité (INRS), in 2014 , France had around 3 million lone workers across all sectors..

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    What are the risks of working alone?

    The main risk of lone working is the absence of help in the event of a workplace accident.

    Isolating workers makes it impossible for them to call for help or obtain outside assistance in the event of an incident.

    🔍 Focus: The risk of working alone is amplified for jobs involving particular risks, such as working in confined spaces or at heights.

    In addition,working in isolation exposes workers to psychosocial risks , particularly due to the fear of being left to one’s own devices or to boredom and loneliness in certain roles (particularly supervisory positions).

    What are the regulations governing lone working?

    As for all occupational hazards, regulations require employers to(Article L4121-1 C.Trav.) :

    • carry out actions to prevent occupational hazards;
    • provide information and training;
    • set up a suitable organization and resources.

    In addition to these general rules, the regulations also lay down rules applicable to specific isolated jobs.

    Thus, in the case of work carried out by an external company and when the operation is carried out at night, in an isolated location or at a time when the activity of the user company is interrupted, the head of the external company must ensure that no worker is working alone in a location where he or she cannot be rapidly rescued(article R4512-13 C. Trav.).

    In addition, there are several prohibitions for lone workers carrying out maintenance and servicing work on permanently installed elevating equipment (elevators, goods elevators, escalators, moving walkways, etc.), notably the manual carrying of a mass in excess of 30 kg, or the laying or removal of elevator traction cables(Article R4543-20 C.Trav.).

    🔍 Focus: For further information, please consult the section of the French Labor Code dedicated to maintenance work on lifting equipment.

    Finally, for certain tasks or jobs involving particular risks, it is forbidden for workers to remain alone or unsupervised:

    How can you prevent the risks associated with working alone?

    Risk assessment

    The first aim of the risk assessment is to identify all isolated workstations and all work situations in which workers find themselves isolated.

    This identification must take into account all the circumstances, working conditions and factors that could contribute to worker isolation (ambient noise, visual obstacles, distances from other workers, independence of the workstation, frequency of use, etc.).

    The workstation and the tasks to be performed must also be precisely defined, so that the associated risks can be determined.

    Then, in order to best determine the preventive measures that will need to be taken, the assessment of the risks of isolated work must precisely define the characteristics of the isolation, namely :

    • geographical isolation;
    • visual isolation;
    • sound insulation ;
    • duration of isolation ;
    • ...

    Finally,the personal characteristics of workers, such as gender, age or seniority, play an important role in risk prevention, and must therefore be taken into account in this assessment.

    🔍 Focus: to illustrate, in this case law, a worker was killed when he fell from a pole on a building site. The worker was alone and working with the aid of a harness. The worker's isolation was called into question (Cass. crim. November 3, 1998, no. 97-85.236).

    Preventive measures

    Preventing the risks of working alone is based mainly on :

    - monitoring lone workers ;

    - setting up a warning system in the event of an accident;

    - rescue organization.

    The first step is to implement organizational measures to limit lone working or reduce its risks: reorganize the workstation or its environment, reduce the duration of interventions, install collective and individual protection devices, etc.

    Worker monitoring

    Monitoring lone workers ensures that no incident or accident occurs during the work period.

    This monitoring can be carried out remotely by a designated person, using a portable means of communication (walkie-talkie or telephone). Checks can be carried out at the start and end of shifts, and at regular intervals.

    Isolated worker alarm device (DATI)

    To prevent the risks of working alone, and in accordance with the general principles of occupational risk prevention, the employer must provide the lone worker with a means of alerting the supervisory post in the event of an accident.

    The Isolated Worker Alarm Device (IWAD) operates either by manual activation or by using sensors to detect an abnormal position of the worker. The latter solution is particularly effective if an accident prevents the worker from triggering his IWAS manually.

    In the event of an accident, DATI sensors may be able to detect prolonged immobilization or an abnormal position of the worker (lying or sitting).

    🔍 Focus: There are many different types of DATI, such as bracelets, small transmitters to be attached to the belt, walkie-talkies, telephones, etc. Whatever form you choose , make sure the DATI is adapted to the worker's isolation and workstation. Whatever form you choose, make sure the DATI is adapted to the worker's isolation and workstation.

    Emergency services

    When the lone worker or the DATI sends an alarm signal to the monitoring station, the latter contacts the worker to confirm or deny the alarm.

    In the event of a confirmed alarm, the monitoring station must take over and call the emergency services immediately , so that the worker can get help as quickly as possible. To this end, it is important that the emergency services are informed of the isolated worker's work area.

    Some DATIs also feature a GPS signal, enabling the lone worker to be precisely located. This GPS signal is particularly useful when the worker is working over a large geographical area.

    Worker training

    Finally, in line with general risk prevention principles, employers must provide training and information for their employees.

    Information and training for isolated workers must therefore take the following points into account:

    • training in the use of a lone worker alarm system (DATI);
    • information on the risks of working alone and on the risks of the workstation;
    • information on the operation of the monitoring station;
    • information on the operation of the emergency services ;
    • precise definition of the workstation and the tasks to be performed, to avoid task overruns ;
    • information on measures to prevent the risks of working alone ;
    • ...

    What does an employer risk in the event of a lone worker accident?

    Employers may be held civilly and criminally liable ifrisk prevention measures are absent, insufficient or inadequate (Cass. crim. December 5, 2000, no. 00-82.108).

    In this case, a lone worker died during rail traffic maintenance work. The isolation of the worker, who was out of sight of the shunting supervisor, and the absence of any means of communication were blamed.

    As a reminder, failure to comply with a duty of care or safety imposed by law or regulation renders the employer criminally liable, particularly in the following three cases:

    Regulatory Aspects Legal Requirements & Preventive Measures Prohibitions & Legal Risks
    🔎 Definition & DUERP Criteria (Recommendation R416): Out of sight, out of earshot, with no possibility of outside assistance, AND while performing hazardous work.
    Mandatory assessment: Identification of all types of isolation (geographic, visual, auditory, temporal) and systematic inclusion in the Single Document (DUERP).
    ⚠️ Criminal Liability:
    In the event of an accident without prompt assistance (due to the absence of a DATI or radio), the employer may face prosecution for:
    • Endangering others
    • Injury or involuntary manslaughter (Case law from 1998 and 2000).
    🚫 Prohibitions on working alone It is strictly prohibited to leave a worker alone when performing the following tasks:
    • Work at heights requiring a harness or rope access techniques (Art. R4323-61).
    • Operations in hyperbaric environments (Art. R4461-37).
    • Work in confined spaces (INRS Guide ED 6184).
    • Certain maintenance tasks on elevators and lifting equipment (Art. R4543-20).
    🛠️ Technical & Human Measures Mandatory DATI devices: Equipment equipped with manual alarms and automatic sensors that detect loss of verticality or prolonged immobility (with GPS tracking if the area is large).
    Emergency response procedures: Strict “verification” procedure carried out by a designated monitoring station, along with periodic checks (at the start, middle, and end of each shift).
    Training: Mandatory training for employees on the use of DATI devices and awareness of the psychosocial risks associated with isolation.