Pilot study comparing the efficacy of two cleaning techniques in reducing environmental contamination with cyclophosphamide.

Objective: Compare the efficacy of the cleaning technique usually employed in our healthcare facility to eliminate environmental contamination with cyclophosphamide with that of the Surface Safe commercial kit.

Methods: This is a three-step evaluative and comparative study involving: (i) the voluntary contamination of the surface of a hood with a pre-established quantity of cyclophosphamide (20,000,000 ng), (ii) the cleaning of the work surface of the hood using a cleaning technique usually employed in our healthcare facility or that of the product Surface Safe, and (iii) the quantification of cyclophosphamide detected on the work surface. The usual cleaning technique involves the use of a mixture of 0.05% chlorhexidine and 70% ethyl alcohol to clean surfaces, whereas the product Surface Safe involves a combined two-step sodium hypochlorite and sodium thiosulfate wash.

Results: The median concentrations of cyclophosphamide detected after the use of the usual technique and the product Surface Safe came to 165 ng cm(-2) (40-570) and 65 ng cm(-2) (57-110), respectively. The results obtained showed an average 99.5% efficacy in reducing the quantity of cyclophosphamide (ng) detected on the work surface for each of the two techniques that were evaluated.

Conclusion: The study demonstrates that reducing the residual concentration of cyclophosphamide on work surfaces to levels lower than 1 ng cm(-2) remains difficult despite the use of cleaning techniques with a high percentage of efficacy. It stressed the importance of combining two successive cleaning techniques to maximally restrict the residual concentration of hazardous drugs and suggests the use of a combination of sodium hypochlorite and sodium thiosulfate to best reduce environmental contamination levels.