Examining factors that influence the effectiveness of cleaning antineoplastic drugs from drug preparation surfaces: a pilot study

Occupational exposure to antineoplastic drugs has been documented to result in various adverse health effects. Despite the implementation of control measures to minimize exposure, detectable levels of drug residual are still found on hospital work surfaces. Cleaning these surfaces is considered as one means to minimize the exposure potential. However, there are no consistent guiding principles related to cleaning of contaminated surfaces resulting in hospitals to adopt varying practices. As such, this pilot study sought to evaluate current cleaning protocols and identify those factors that were most effective in reducing contamination on drug preparation surfaces. Three cleaning variables were examined: (1) type of cleaning agent (CaviCide®, Phenokil II™, bleach and chlorhexidine), (2) application method of cleaning agent (directly onto surface or indirectly onto a wipe) and (3) use of isopropyl alcohol after cleaning agent application. Known concentrations of antineoplastic drugs (either methotrexate or cyclophosphamide) were placed on a stainless steel swatch and then, systematically, each of the three cleaning variables was tested. Surface wipes were collected and quantified using high-performance liquid chromatography-tandem mass spectrometry to determine the percent residual of drug remaining (with 100% being complete elimination of the drug). No one single cleaning agent proved to be effective in completely eliminating all drug contamination. The method of application had minimal effect on the amount of drug residual. In general, application of isopropyl alcohol after the use of cleaning agent further reduced the level of drug contamination although measureable levels of drug were still found in some cases.