A TSO is a Safety Officer appointed to support the relevant Department Head or Technical Coordinator, through the DSO or LEXGLIMOS, in fulfilling Safety obligations for specific buildings and premises. The TSO acts on behalf of the relevant DSO or LEXGLIMOS and reports to them, as applicable.

Regarding appointments:

Where buildings or premises are shared, the relevant parties shall be involved in the appointment: Department Heads agree on a common TSO in consultation with their DSOs; for Department–Large Experiment sharing, the Department Head appoints the TSO in consultation with the DSO, Technical Coordinator and LEXGLIMOS.

Each appointment shall be made in writing, specifying the mandate and the buildings and premises concerned.

For buildings and premises under the responsibility of a Department, the TSO is appointed by the Department Head, in consultation with the DSO, from among employed Members of the Personnel of the Department.

For the experimental areas of a Large Experiment, the Technical Coordinator appoints the TSO from among Members of the Personnel participating in the Large Experiment, in consultation with the LEXGLIMOS and the Department Head of the TSO or, if the TSO is an associated Member of the Personnel, their home institution.

Yes, each TSO shall have a deputy who replaces them in their absence. It is recommended that they work together as a team to share workload and experience.

The physical scope of the TSO corresponds to the buildings and premises for which they have been formally appointed. In other words, the TSO has a territorial scope: they are appointed for a given building or area, not for an activity, equipment or a specific risk. Within this scope, the TSO’s routine follow-up primarily concerns common, shared or circulation areas, i.e. areas used by several people, groups or services, and which are not exclusively assigned to a specific activity or responsible person. This can typically include Safety-relevant aspects of:

• corridors; staircases; roofs;
• sanitary facilities for Safety-relevant issues affecting users or the building;
• meeting rooms; copy room;
• break room, kitchen, cafeteria, refectory, generally in support of the Location Responsible, where one has been appointed;
• access routes to and from the building, including emergency exits and evacuation paths;
• more generally, rooms or spaces that can be used by all occupants;

The TSO is not the direct responsible person for spaces assigned to an activity, equipment or a specific risk. In particular, routine TSO follow-up does not normally cover:

• offices; laboratories; workshops; technical or experimental areas;
• areas presenting specific risks for which, in principle, another responsible person has been appointed, for example a Location Responsible, a Workshop Supervisor or an activity leader.

These spaces remain under the responsibility of their users or specific Safety responsible persons, while remaining in interface with the TSO for general building-related aspects.

Parking areas are generally outside the TSO’s routine building follow-up and usually managed by SCE. However, the TSO may still raise, or relay Safety concerns observed in these areas, especially when they affect access to the building, evacuation routes, assembly points or interfaces with the building.

Yes, there is a 2-day classroom course which all new TSOs shall do before being appointed. There is no refresher course but long standing TSO’s are welcome to do the TSO course as it is updated from time to time with the latest regulations and practices.

Budget arrangements depend on the internal policy of each Department or Large Experiment and should be communicated to the TSO. Many CERN services can be requested without a budget code. Where a budget code is required, the TSO should seek support from the DSO/LEXGLIMOS, who may involve the Department Head, Technical Coordinator or Space Manager as appropriate.

In an emergency, the TSO, like everyone at CERN, must first ensure their own safety, avoid putting themselves at risk and follow the applicable emergency instructions. Everyone is also expected, where this can be done safely, to raise the alarm, assist people in difficulty and warn others of an immediate danger.

The TSO’s additional role in specific emergency situations is described below.

Major incident with CERN crisis management activated: the TSO may be asked to contribute, for example by providing local building information or supporting communication.

Fire, smoke or evacuation alarm: Once the assembly point reached, gather relevant information from the emergency guides and report it to the Fire Officer.

The TSO is involved in IMPACT requests relevant to the buildings or premises for which they have been appointed, so that they are informed of planned activities and can identify any potential impact on the building, common areas, access routes, evacuation arrangements or other ongoing activities.

If the TSO identifies a risk of co-activity or a potential conflict between several activities, they should alert the persons concerned and facilitate contact between them. The TSO therefore acts as a territorial point of contact, without taking on the coordination of the activities or responsibility for their execution. Typical situations in which the TSO may need to react include, for example:

• two or more activities taking place in the same area where they may interfere with each other, for example work at height above another activity or lifting/handling operations close to people working below;
• transport or movement of large or heavy equipment through or close to an active work area;
• an activity affecting access, circulation or evacuation arrangements needed by other occupants or activities.

In such cases, the TSO is not expected to assess or coordinate the technical aspects of the activities themselves. Their role is to flag the potential interface and ensure that the relevant responsible persons are put in contact. When reviewing an IMPACT request, if there is any doubt about possible co-activity, it is good practice to check the planning of other activities in the building in IMPACT before signing the request.

The TSO’s involvement in IMPACT does not transfer responsibility for the activity to them. The activity remains under the responsibility of the persons or entities responsible for its organisation and execution under the applicable process.

The formal responsibility for implementing the planned evacuation procedure lies with the DSO/LEXGLIMOS. For each building or infrastructure identified as a priority, the DSO/LEXGLIMOS appoints an organiser, who is responsible for coordinating the planned evacuation throughout the procedure.

The TSO acts as a local reference person for the building or premises concerned. Depending on the case, they may support the organiser by providing knowledge of the building, helping to identify existing or required emergency guides, contributing to the update of the emergency guide list. Together, the TSO and the organiser perform the preparatory visit of the building or infrastructure and implement the necessary corrective actions.

The TSO is involved in the preparation and execution of a planned evacuation, and their input is often valuable. However, they do not automatically carry the responsibility for organising it. They only take on the organiser role if this has been explicitly assigned to them by the DSO/LEXGLIMOS.

By way of indication, the corresponding procedure can be found in EDMS: https://edms.cern.ch/document/2254068/

At CERN, the terms “tertiary building” and “machine building” are often used in an operational context, in particular to identify which service is responsible for maintenance or technical support.

For tertiary buildings, maintenance requests are usually handled by the SCE Department. In machine buildings, technical systems such as electricity, lighting, and ventilation are usually maintained by the EN Department. The distinction is important for TSOs because the right support service depends on the category and use of the building. To determine the type of a given building:

Click on “Data” and select “Thematic map/Tertiaire-Machine”

Go to gis.cern.ch

The TSO is given the authority and means needed to fulfil their mandate for the buildings and premises for which they are appointed. To exercise this authority effectively, the TSO shall keep themselves informed regarding Safety matters related to the buildings and premises concerned, including relevant interfaces with activities taking place there. This authority should be understood as the ability to act when a Safety matter may affect the building, common areas, interfaces between activities, access, evacuation routes or the people present.

It does not mean that the TSO becomes responsible for activities taking place in the building, or replaces the persons responsible for the activity, the DSO/LEXGLIMOS, HSE or any specialised Safety role.

In practice, the TSO may use their authority to:

• request additional information about an activity planned in the building;
• ask who is responsible for the activity, equipment or risk concerned;
• request clarification on access, evacuation, coactivity, impact on common areas or interfaces with other occupants;
• ask that the relevant responsible persons to be put in contact;
• raise the need for a VIC, or another coordination step, where applicable;
• escalate to the DSO/LEXGLIMOS if the situation is unclear or may present a risk.

The TSO’s authority supports their role of remaining informed about Safety matters related to the buildings and premises concerned, keeping relevant people informed, collaborating with those responsible for equipment and activities hosted there, and contributing to Safety follow-up. When works or services are involved, the TSO may raise concerns or request clarification, but formal Safety coordination remains with the persons or entities designated under the applicable Works and Services process.

Overall Safety responsibility remains with line management, supported by the DSO/LEXGLIMOS. In practice, the TSO is expected to manage Emergency Guide coverage for the buildings and premises for which they are appointed. This includes keeping the assignments up to date in ROLES, nominating or revoking Emergency Guides as needed, and identifying gaps resulting from changes in occupancy or building use.

The DSO/LEXGLIMOS provides support where needed, in particular where sufficient coverage cannot be achieved locally or where several Departments or Large Experiments share the same premises.

The appropriate number and distribution of Emergency Guides should take account of the building’s use and foreseeable occupancy. Emergency Guide coverage is also reviewed during the preparation of planned evacuations, in collaboration with the organiser, the TSO and the DSO/LEXGLIMOS.

Sauf indication contraire, les références au TSO ci-dessous s’appliquent également au TSO adjoint (DTSO) lorsqu’il exerce cette fonction.