Evaluation of surface contamination with cyclophosphamide and paclitaxel to control the risk of occupational exposure to hazardous drugs in two hospitals of a comprehensive cancer center

Objective
Since 2018, an annual monitoring of environmental contamination by cyclophosphamide (100 samples/year) was carried out in two hospitals of our institution. Recently, the French Agency for Food, Environmental and Occupational Health & Safety published a report classifying work involving exposure to cytotoxic substances as carcinogenic processes. We report here the results of the 3rd environmental monitoring campaign performed in 2021.

Methods
A new LC-MS/MS method was developed and validated to quantify traces (ng) of cyclophosphamide and paclitaxel. Wipe samples were performed in anticancer production units and daily care units (DCU) at two hospital sites with the contribution of pharmacy students. The main points of investigation were: 1) the effectiveness of the decontamination procedure for industrial vials; 2) contamination of the reception and administration areas; 3) external contamination of chemotherapy bags (from the infusion stand); 4) the effectiveness of floor cleaning. The results were expressed in ng/cm2, considering contamination below 0.100 ng/cm2 as "safe".

Results
A total of 109 samples were carried out: 93% were positive for cyclophosphamide and 91% for paclitaxel. The results obtained confirm the effectiveness of the decontamination procedure for industrial vials: from [0.003-0.131] to [0.003-0.022] ng/cm2 for cyclophosphamide vials, and from [NQ-0.146] to [ND-0.006] ng/cm2 for paclitaxel vials. Cyclophosphamide contamination in the administration areas was reduced: from [ND-27.32] (2018) to [ND-5.642] ng/cm2 (2021). Nevertheless, contamination of the infusion pumps was higher for paclitaxel ([0.005-1.191] ng/cm2) compared to cyclophosphamide. Some chemotherapy bags showed significant external contamination of cyclophosphamide ([0.001- >6,985] ng/cm2) and paclitaxel ([ND-0.517] ng/cm2), particularly those prepared by the PharmaHelp^® automate. On the floor, we observed an effectiveness of cleaning carried out by the external contracted company or by using Klercide^TMneutral detergent, but mainly for cyclophosphamide. All these results were communicated to healthcare workers.

Discussion-Conclusion
Occupational exposure to hazardous drugs is increasingly discussed in Europe and therefore in France. During the Covid-19 pandemic, the disinfection procedures have been improved to the benefit of a reduction in surface contamination in the DCUs studied. Our cleaning protocols seem to be more effective for hydrophilic molecules considering the results observed for paclitaxel. These results also confirm the need to develop multi-component analyzes in our institution to control more and more the risk of occupational exposure.

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