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

Abstract

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 (20000000 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.