From fossil to bio-circular plastics: the environmental benefits of bio-attributed acrylonitrile butadiene styrene in single-use cystoscopes

Background

Single-use cystoscopes are increasingly adopted in urology, but concerns regarding their environmental footprint persist. Substituting conventional fossil-based plastics with bio-attributed materials may reduce life cycle impacts, yet the magnitude and robustness of this benefit remain uncertain.

Objective

To evaluate the environmental performance of a single-use flexible cystoscope (aScope™ 4 Cysto; Ambu A/S, Copenhagen, Denmark) incorporating bio-attributed acrylonitrile butadiene styrene (Bio-ABS) using a cradle-to-grave life cycle assessment (LCA).

Methods

An attributional LCA was performed according to the International Organization for Standardization (ISO) 14040/44 standards, investigating the impact of the introduction of Bio-ABS (50:50 mass balance with fossil feedstock). The functional unit was one cystoscopy procedure. System boundaries included raw material extraction, manufacturing and sterilisation, packaging, distribution, use, and end-of-life treatment. Two geographic scenarios were evaluated (UK and USA). Climate change (kg CO2 equivalents [kg CO2 eq.]) was the primary impact category, with others including human toxicity, particulate matter, and resource use. Sensitivity analyses assessed alternative allocations for bio-circular feedstock and variations in sterilisation utilities.

Results

The total carbon footprint of the cystoscope decreased from 1.63 to 1.46 kg CO2 eq. (USA) and from 1.74 to 1.61 kg CO2 eq. (UK) with Bio-ABS, corresponding to reductions of 10% and 7.5%, respectively. Raw material production and sterilisation were the dominant contributors (55–60% of total impact), with packaging accounting for 22–24%. Component-level analysis showed plastics as the primary driver of climate impacts, while electronics and metals contributed disproportionately to resource use and toxicity categories. Sensitivity analyses confirmed the robustness of the Bio-ABS benefit, even when environmental burdens were assigned to bio-feedstock.

Conclusions

Incorporating bio-attributed plastics into single-use cystoscopes yields a consistent reduction in life cycle carbon footprint. While material substitution provides measurable benefits, packaging redesign and optimised logistics represent additional opportunities for environmental impact reduction. These findings inform sustainable endoscopic practice and highlight the importance of transparent life cycle modelling in medical device evaluation.