Longitudinal evaluation of environmental contamination with hazardous drugs by surface wipe sampling

Exposure of healthcare workers to hazardous drugs can lead to adverse health effects supporting the importance of a continuous monitoring program, for example, by taking surface wipe samples. The objective was to describe the results of repeated monitoring of contamination with hazardous drugs on multiple surfaces in a hospital pharmacy and at two wards using standardized preparation techniques and cleaning procedures.

Twelve surfaces in the hospital pharmacy and at two wards were sampled and analyzed for contamination with the hazardous drugs cyclophosphamide, doxorubicin, 5-fluorouracil, gemcitabine, methotrexate, and paclitaxel. The drugs were prepared with a closed-system drug transfer device (CSTD). Sampling of the drugs was performed in four trials during eight months. Liquid chromatography tandem mass spectrometry was used for the analysis of the drugs.

During the four trials, contamination with five of the six hazardous drugs was found on half of the surfaces in the pharmacy and in a ward. Seventeen out of 288 possible outcomes were positive (6%), with the biological safety cabinet grate (n = 6) and scanner (n = 5) most frequently contaminated. The highest level of contamination was observed on the pass-thru window (cyclophosphamide: 2.90 ng/cm²) and the touch screen of the Diana device (5-fluorouracil: 2.38 ng/cm²). Both levels were below the action level of 10 ng/cm².

The long-term use of a CSTD in combination with appropriate cleaning has proven effective in achieving low levels of surface contamination with hazardous drugs.