Assessment of the carbon footprint and cost-effectiveness of endoscopic liquid waste processing methods

Endoscopy is a major producer of hospital waste. Liquid waste collected during endoscopic procedures represents a third of endoscopy waste and is often managed as regulated medical waste (RMW), costing more and emitting more greenhouse gases (GHGs) than regular landfill waste. We assessed the carbon footprint and financial impact of alternative processing methods to RMW.After 1 month of prospectively weighing endoscopic liquid waste, costs (€) and GHG emissions (kgCO2e) were calculated using the Carebone tool to compare the following processing methods to standard RMW: (a) solidification - aspiration canister contents are made less prone to leakage by including a jellifying additive and can be disposed of in landfill waste bags instead of RMW; (b) urban sewer disposal (USD) - fluids are eliminated into sewers by using a dedicated system instead of aspiration canisters. Costs and GHG emissions were modelled according to the different scenarios.Mean procedure-related waste was 1.56 kg per patient, one-third of which was liquid waste. Compared with RMW (assuming 0.5 L of waste per endoscopic procedure), a center treating 4000 patients / year would save 923 € and avoid 1440 kgCO2e in GHG emissions with solidification, while USD would cost 105 898 € more and avoid only 96.5 kgCO2e. Different caseload and volume assumptions are discussed.Endoscopic procedure-related liquid waste represents a third of the waste emitted per patient in an endoscopy unit. Solidification allows fluids to be safely reallocated to landfill waste and may reduce processing costs and environmental impact. USD appears to be neither environmentally nor economically beneficial for endoscopy units.