CMS Safety Mandate

The CMS Safety Office works towards the achievement of the CERN’s Occupational Health and Safety objectives

According to the General Safety Instruction GSI-SO-4 – Large Experiment Group Leader In Matters of Safety (LEXGLIMOS) EDMS 1403716:

“The LEXGLIMOS shall support the Technical Coordinator and the Collaborating Institutions participating in the Large Experiment concerned in fulfilling their obligations in matters of Safety.
He shall in particular:

  • Keep himself and his Technical Coordinator informed regarding all aspects of Safety within his Large Experiment
  • Assess the means necessary for all persons participating in his Large Experiment and present on the CERN site to fulfil their obligations in matters of Safety, including training and information, propose appropriate measures to his Technical Coordinator and monitor their implementation
  • Propose and monitor the implementation of appropriate measures to ensure the compliance of Installations, activities and projects under the responsibility of his Large Experiment with the CERN Safety Rules and best practices
  • Support his Technical Coordinator with a view to the implementation of the CERN Safety Objectives in his Large Experiment and the definition of the associated priorities and time scales
  • Oversee the establishment and updating of Safety Files and contribute to the establishment and updating of Safety Folders
  • Contribute to the improvement of Safety in his Large Experiment, in particular by reviewing Incidents and by defining appropriate measures and monitoring their implementation
  • Monitor the follow-up of Safety audits
  • Support his Technical Coordinator in obtaining Safety clearance in accordance with the applicable CERN Safety Rules
  • Oversee the organisation of Safety exercises in accordance with the applicable CERN Safety Rules
  • Co-ordinate the work of the other Safety Officers and Safety Support Officers within his Large Experiment
  • Represent his Large Experiment in advisory bodies in matters of Safety as defined in the applicable CERN Safety Rules
  • Execute any other Safety tasks as may be assigned to him by his Technical Coordinator or a CERN Safety Rule
  • Collaborate with other LEXGLIMOSes and Departmental Safety Officers (DSOs), as well as with the HSE Unit, the Medical Service and the Fire and Rescue Service, as required
  • Liaise with the Safety Correspondents of the Collaborating Institutions participating in his Large Experiment, as required.

The LEXGLIMOS shall further support his Technical Coordinator to ensure the safe interaction of the installations, activities and projects under the responsibility of his Large Experiment with those under the responsibility of other Large Experiments or Departments. He shall, in particular, pay attention to the consistency between the Safety measures and actions of his Large Experiment and those of other Large Experiments and Departments and shall collaborate with other LEXGLIMOSes and DSOs, as required.”


The baseline for the Safety approach and prevention applied at CMS experiment lies on the 9 general principles of prevention as defined in the European Directive 89/391/EEC.


  • to ensure the best possible protection in health and safety matters of all persons, irrespective of their status, participating in the CMS activities or present on its site, as well as of the population living in the vicinity of its installations;
  • to limit the impact of the CMS activities on the environment;
  • to fulfil legal requirements (Safety Rules established by the Organization and/or the relevant laws and the regulations of the Host States applied on a territorial basis) and to guarantee the use of best practice in matters of Safety;
  • to assess, evaluate and eliminate/minimize hazards and risks;
  • to reduce frequency and severity of injuries and incidents;
  • to strengthen and to continual improve the Safety Management System;
  • to consult, support and motivate personnel in promoting safety and proposals for improvement.

  • uses systems and procedures aiming at ensuring Safety in its activities;
  • has an organizational structure identifying clear roles and responsibilities;
  • applies Safety Rules established and updated by CERN HSE Unit and/or Host States and ensures compliance therewith;
  • watches brief on emerging trends and the evolution of laws, regulations and best practices relevant to the activities of CMS.
  • verifies and leads design, commissioning and operation of plants, systems and equipment according to legal and technical requirements and within the defined operating parameters;
  • applies proper maintenance strategies for plants, systems and equipment;
  • identifies and assesses, according to the Safety Management System procedures, hazards and risks related to plants, systems, equipment, activities and their modifications;
  • verifies and assesses, in terms of Safety, the reliability of contractors;
  • implements technical and organizational measures and means aimed at handling emergency situations;
  • organizes and updates continually trainings on Safety matters for persons concerned;
  • communicates proactively in Safety matters with persons participating in the CMS activities or present on its te, with the Host States and the general public, and collaborates with its Host States;
  • uses advanced document management systems to create, update and control documented information;
  • manages and updates CMS websites reporting relevant information about Safety;
  • defines, follows-up and updates prevention objectives based on risk assessment, lessons learnt and experience gained;
  • coordinates activities in order to eliminate/minimize hazards and risks;
  • analyzes and follows-upon incidents and nonconformities to prevent their recurrence and defines corrective actions to mitigate their present and potential effects;
  • is committed in periodical review, performance evaluation and safety audit of the Safety Management System to ensure the implementation and diffusion of the Safety Policy and the System itself;
  • takes steps to implement continual improvement of Safety according to ISO 45001.

Further reference:
Under the CMS Safety Mandate (EDMS 1428221)
Under Safety Regulation SR-SO (EDMS 1389540)
Under General Safety Instruction GSI-SO-4 (EDMS 1403716)