Highly toxic drugs for treating cancer were prepared at Farnham Hospital in Surrey using this cabinet. These drugs were prepared ready for use, for example loaded into saline drips or syringes. In this form they had to be used within a few hours and kept completely sterile. The cabinet housed a special system to re-circulate air through filters. This protected the drugs from bacteria or viruses in the air and the operator from hazardous substances. Many of the drugs prepared could cause cancer if they came into contact with anyone other than the patient.