In the establishments mentioned in article L. 4521-1, when a worker or the manager of an external company or a self-employed worker is called upon to carry out work which may present particular risks due to its nature or the proximity of this installation, the manager of the user company and the manager of the external company jointly define the prevention measures provided for in articles L. 4121-1 to L. 4121-4.
The head of the user company’s establishment shall ensure that the external company complies with the measures that the latter is responsible for applying, taking into account the specific nature of the establishment, prior to carrying out the operation, during its progress and on its completion.