The challenge was to decontaminate the pharmaceutical environments from agents and molecules constituting the active ingredients of the antibiotics - OEB 4 and 5 - in order to make the spaces available for new productions. Few people are aware of the danger of these ingredients when taken in large doses. Personnel exposure is important and that's why due training and protection were one of our top priorities. Our work consists mainly in manual operations in confined negative pressure spaces which are monitored to ensure absolute compliance with set procedures.