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A before/after intervention study to determine impact on life cycle carbon footprint of converting from single-use to reusable sharps containers in 40 United Kingdom NHS Trusts


Grimmond, Terry et al. (2021), A before/after intervention study to determine impact on life cycle carbon footprint of converting from single-use to reusable sharps containers in 40 United Kingdom NHS Trusts, Dryad, Dataset,


The purpose of this study was to compare Global Warming Potential (GWP) of hospitals converting from single-use to reusable sharps containers (SSC, RSC). Does conversion to RSC result in GWP reduction? Using BS PAS 2050:2011 principles, a retrospective, before/after intervention quantitative model together with a purpose-designed, attributional “cradle-to-grave” life cycle tool, were used to determine the annual GHG emissions of the two sharps containment systems. Functional unit was total fill-line litres (FLL) of sharps containers needed to dispose of sharps for one-year period in 40 trusts. Scope 1, 2 and 3 emissions were included. Results were workload-normalised using NHS national hospital patient-workload indicators. A sensitivity analysis examined areas of data variability.

Setting. Acute-care hospital trusts in United Kingdom.

Participants. 40 NHS hospital Trusts using RSC.

Intervention. Conversion from SSC to RSC. SSC and RSC usage details in 17 base-line trusts immediately prior to 2018 were applied to the RSC usage details of the 40 trusts using RSC in 2019.

The comparison of GWP calculated in carbon dioxide equivalents (CO2e) generated in the manufacture, transport, service and disposal of 12 months, hospital-wide usage of both containment systems in the 40 trusts. The 40 trusts converting to RSC reduced their combined annual GWP by 3267.4 tonnes CO2e (-83.9%); eliminated incineration of 900.8 tonnes of plastic; eliminated disposal/recycling of 132.5 tonnes of cardboard; and reduced container exchanges by 61.1%. GHG as kg CO2e/1000 FLL were 313.0 and 50.7 for SSC and RSC systems respectively. A sensitivity analysis showed substantial GHG reductions within unit processes could be achieved, however their impact on relevant final GWP comparison varied <5% from base comparison. Adopting RSC is an example of a sustainable purchasing decision that can assist trusts meet NHS GHG reduction targets and can reduce GWP permanently with minimal staff behaviour-change.


These data were collected from primary sources as far as practical. Where unavailable from primary sources, data were collected from reputable secondary sources. Secondary databases were chosen for their representativeness: temporally (i.e. data published within last five years); geographically (i.e. sourced from same region/country in which the process was carried out); and applicability (i.e. the process was identical or as close as possible to the process in the SSC and RSC life-cycles.

In gathering data, relevance, completeness, consistency, accuracy and transparency were paramount.

Usage Notes

A knowledge of Life Cycle Assessments, particularly Life Cycle Carbon Footprints and Global Warming Potential would assist readers understand the need for detailed data on Unit Processes and their GHG Conversion Factors, and how these are interconnected to determine the GWP of a product carbon footprint from cardle to grave.

The data are presented in sufficient detail (with sources) for researchers to understand and check the calculations made to determine the outcome of the comparison of the product systems, and to ascertain the certainty level of the data used in the final calculation.


Sharpsmart UK, Award: 2019-1

Sharpsmart UK, Award: 2019-1