In a sterile room of a pharmaceutical plant, a technician became unconscious while validating the cleaning phase on a reactor. This 32 year-old technician, who had been working in the room for 7 years, entered into the reactor used for synthesising antibiotics and corticosteroids without first checking out the equipment (which entails electrical and mechanical deactivation of all moving parts and verification of the breathable and non-explosive atmosphere). He lost consciousness from anoxia due to the nitrogen inerting and after inhaling solvent vapours present inside the reactor. The employee was hospitalised in very critical condition (therapeutic coma) but died 19 days later. Afterwards, the operator made a point of reminding personnel at all sites of the rules for entering confined spaces, in addition to the existence of EHS management system tools intended to identify any and all discrepancies. The police and labour inspection officials led the follow-up investigation.