White Paper

Sustainable Materials and Design Innovations in Instrument Sterilisers and Bedpan Washer-Disinfectors

October 2026

Disclaimer

This content is provided for information only. The authors make no representation or warranty regarding the accuracy, completeness or currency of the content. No information in this whitepaper should be construed as medical advice. Readers should seek appropriate professional guidance before acting on any information contained in this document. The authors expressly disclaim all liability for any direct or indirect loss or damage arising from the use of or reliance on this information.

Introduction

This paper sets out material, design, operating and procurement measures that reduce the life cycle environmental impact of steam sterilisers and bedpan washer-disinfectors (WDs) without changing the reprocessing requirements of AS 5369:2023. It quantifies use-phase and embodied emissions for a hospital steam steriliser from Australian measured data, ranks the measures by effect, and gives actions for procurement officers, manufacturers and standards bodies.

Sustainable Materials in Sterilisers and Disinfectors

Stainless Steel: Chambers, jackets, pipework and frames are typically austenitic stainless steel. Cradle-to-gate emissions for stainless steel production, including scope 1, 2 and 3, depend on scrap content as follows.

Raising scrap content from 30 % to 85 % reduces production emissions by 71 %, or 4.85 t CO2-e per tonne of steel. About 85 % of end-of-life stainless steel is recycled. Request a declaration of scrap content for the stainless steel used.

Polymers and Elastomers: Mark plastic parts with ISO 11469 material codes, minimise the number of polymer types and join parts with fasteners rather than adhesives so that materials separate at end of life. Use recycled or bio-based polymers only for parts outside the chamber and water path, where they cannot affect validation or material compatibility.

Electronics: Mount controls, power electronics and wiring as removable assemblies so they can be separated as e-waste. Specify freedom from the substances restricted by EU RoHS.

Design Strategies for Improved Environmental Performance

Modularity and Repair: Configure the steam generator, vacuum system, controls and door assemblies as separately replaceable modules with service access, standard fasteners and components common across a model range. Design seals, valves, pumps and heating elements for replacement in service, so that service life is limited by the chamber and pressure vessel. Provide service manuals, parts lists and diagnostic access to the maintaining organisation.

Upgrades: AS 5369:2023 requires changes to control software that affect operation to be validated. Release control upgrades as documented software versions with change records so installed units can be upgraded and requalified rather than replaced.

Service Life: Annualised embodied emissions fall in proportion to service life, e.g. extending life from 10 to 15 years reduces them by 33 %.

Standby Control: Provide programmable start-up and shutdown schedules and automatic shutdown of the steam generator and jacket heating after a set idle time.

Insulation: Insulate the chamber, jacket, steam generator and pipework to reduce standby heat loss and plant room heat load.

Water Use: Control drain tempering water with a thermostatic valve that admits cooling water only when discharge would exceed the trade waste temperature limit, e.g. 38 deg C [100 deg F] for Sydney Water. Recirculate vacuum pump cooling water. US EPA guidance reports reductions of up to 90 % in tempering water and 50 to 80 % in vacuum pump cooling water from these retrofits.

Heat Recovery: Recover heat from drain condensate to preheat feed water where flow and temperature justify a heat exchanger.

Metering: Record electricity, water and steam consumption for each cycle and in standby, and export it with the cycle record.

Bedpan WDs: Match water and energy to the load with programme selection. Control thermal disinfection to the specified A0 value with minimal temperature overshoot. Treat supply water to limit scale on heating surfaces and steam generators, which reduces heat transfer and increases energy use and failures. AS 5369:2023 notes that water with hardness not exceeding 150 mg/L and chloride not exceeding 120 mg/L may be suitable for the final rinse of bedpan WDs.

Lifecycle Assessment: Emissions, Energy, and Waste Impacts

Method: Assess life cycle impacts to ISO 14040 and ISO 14044, covering materials, manufacture, transport, use and end of life. For reprocessing equipment, quantify use-phase electricity, steam and water first.

Measured Use Phase: McGain et al. (2017) metered one Australian hospital steam steriliser for 304 days. It completed 2,173 active cycles, about 7 per day. Consumption per mass sterilised was 1.9 kWh/kg [0.86 kWh/lb] of electricity and 58 L/kg [6.95 US gal/lb] of water. Standby used 40 % of the electricity and 21 % of the water. Regression gave electricity per cycle of 15.7 kWh plus 0.14 kWh per kg [0.064 kWh per lb] of load, with moderate fit, so light loads are inefficient. Consumption fell from 3 kWh/kg [1.36 kWh/lb] and 200 L/kg [24.0 US gal/lb] for 5 kg [11 lb] loads to 0.5 kWh/kg [0.23 kWh/lb] and 20 L/kg [2.4 US gal/lb] for 40 kg [88 lb] loads.

Use Phase and Embodied Emissions: Annualised, the steriliser uses 64,966 kWh and 1,888 kL [499,000 US gal] per year. At the NSW scope 2 factor of 0.64 kg CO2-e/kWh [1.41 lb CO2-e/kWh], electricity emissions are 41.6 t CO2-e per year, or 416 t over 10 years. Assume the unit contains 2 t [4,400 lb] of stainless steel at 30 % scrap content, 13.6 t CO2-e. Even if other materials and manufacture double this figure, embodied emissions are less than 7 % of the 10-year total. Use-phase measures therefore have the largest effect.

Standby: Eliminating standby consumption in this unit would save up to 25,763 kWh, 16.5 t CO2-e and 395 kL [104,000 US gal] per year, A$8,417 at A$0.25 per kWh and A$5 per kL. Restart warm-up reduces the net saving. Shut down sterilisers not needed for the session.

Load Consolidation: With about 15.7 kWh fixed per cycle, eight 5 kg [11 lb] loads use 110 kWh more than one 40 kg [88 lb] load. Schedule cycles at or near the validated maximum load within turnaround requirements.

Carbon Payback: Replace a unit early for efficiency only where the use-phase emissions saved over the remaining life exceed the embodied emissions of the new unit. In the example, a replacement that reduces electricity use by 10 % saves 4.2 t CO2-e per year and repays 13.6 t of embodied emissions in 3.3 years, or 6.5 years if other materials double the embodied total.

Bedpan WD Water: One hospital reported 29 L [7.7 US gal] of potable water per bedpan WD cycle. Measure water, electricity and detergent per cycle on site before comparing options.

Bedpan WDs and Macerators: Macerators dispose of single-use pulp bedpans to sewer. They avoid washing but consume pulp products and add solids to the sewer. WDs reuse bedpans and consume water, energy and detergent each cycle. Peer-reviewed comparisons are limited, and several published comparisons are supplier-commissioned. Compare the systems per use with site data: WD water, electricity and detergent per cycle against pulp product mass, macerator water per cycle, and waste and trade waste charges. Apply infection control requirements first.

End of Life: Decontaminate units before decommissioning. Recover stainless steel as scrap and dispose of controls and wiring as e-waste. In Victoria, landfills cannot accept e-waste, and most business e-waste is priority waste under the Environment Protection Regulations. Confirm requirements in other jurisdictions.

Influences on Manufacturing Standards and Regulations

Reprocessing Standards: AS 5369:2023, ISO 15883, EN 285 and EN 13060 specify process performance and set no limits on energy or water consumption. AS 5369:2023 requires the environmental impact of substances released from cleaning, disinfecting and sterilising agents to be assessed, and control measures to be implemented and documented.

IEC 60601-1-9: This collateral standard sets a process for environmentally conscious design: identify environmental aspects, determine the significant aspects, obtain supply chain information, reduce adverse impacts and provide environmental information. Its scope is medical electrical equipment. Sterilisers and WDs are covered for electrical safety by IEC 61010-2-040, so IEC 60601-1-9 is not a compliance requirement for them. Use its process as a design framework.

Management Systems and Declarations: ISO 14001 covers environmental management at the manufacturing site. ISO 14040 and ISO 14044 cover LCA. ISO 14025 covers Environmental Product Declarations (EPDs).

EU Directives: RoHS restricts lead, mercury, cadmium, hexavalent chromium, PBB, PBDE and four phthalates in electrical and electronic equipment, including medical devices. WEEE sets producer take-back obligations. Both apply to equipment placed on the EU market and do not apply in Australia.

Australian Policy: The National Health and Climate Strategy (2023) includes actions to develop guidelines on green procurement and sustainable resource use, align procurement requirements to decarbonise health system supply chains, and consider reporting of the emissions footprint of health technology products. Water utility trade waste standards set discharge limits, including temperature.

Procurement Guidance for Sustainable Healthcare Equipment

Specify the following in tenders for sterilisers and bedpan WDs and score responses against them.

• Consumption Data: Electricity, steam and water per cycle for each validated cycle at a stated load, and standby power and water per hour, with the measurement method.

• Water Systems: Drain discharge temperature, tempering water control, vacuum pump type and cooling water recirculation.

• Standby Control: Programmable start-up, shutdown and idle shutdown.

• Metering: Per-cycle consumption recorded with the cycle record and exported electronically.

• Materials: Material composition by mass, stainless steel scrap content, ISO 11469 polymer marking and a restricted substance declaration.

• Support: A written commitment to parts and technical support for the planned service life.

• End of Life: Disassembly information and a take-back or recycling route.

Evaluation: Compare bids on whole-of-life cost: installed cost annualised at the real discount rate, plus energy, water, detergent and maintenance at site tariffs over the planned life. Calculate emissions using the current National Greenhouse Accounts Factors for the state.

Audience-Specific Insights and Recommendations

For Manufacturers

Design Process: Apply the IEC 60601-1-9 process to new designs and document the significant environmental aspects and the measures taken.

Data: Declare per-cycle electricity, steam and water for each cycle type at the standard test load, standby consumption and material composition in the IFU or product datasheet. Commission an LCA to ISO 14040 and ISO 14044 and publish an EPD to ISO 14025.

Spare Parts: Supply spares for the support period declared at sale, and provide upgrade kits when components become obsolete.

Refurbishment: Offer refurbishment that replaces wear components and upgrades controls, with full requalification before return to service.

For Hospital Procurement Officers

Verification: Measure electricity and water per cycle and in standby at commissioning and compare with tendered values. Include a contractual remedy where measured consumption exceeds tendered values by more than an agreed tolerance.

Operation: Train staff to use standby schedules, shut down units not needed for the session and consolidate light loads within turnaround requirements. Review metered consumption quarterly.

Reporting: Record annual electricity, water and emissions for each unit, and per kg [lb] processed, to track performance and inform replacement decisions.

For Regulatory Bodies and Standards Organisations

Test Methods: Define standard test methods and declared values for consumption, e.g. kWh and L per cycle per litre of chamber volume at the standard test load for sterilisers, kWh and L per cycle at a defined load for bedpan WDs, and standby consumption per hour.

Disclosure: Require declared consumption values in the IFU, and include them in green procurement guidelines developed under the National Health and Climate Strategy.

Scope: Add an environmentally conscious design requirement equivalent to IEC 60601-1-9 to IEC 61010-2-040 or the reprocessing equipment standards, because the collateral standard does not apply to reprocessing equipment outside the medical electrical equipment scope.

Conclusion

Use-phase electricity and water dominate the life cycle impact of a hospital steam steriliser. In the measured example, standby accounted for 40 % of electricity, and embodied stainless steel was about 3 % of the 10-year emissions total. Prioritise standby control, load consolidation, tempering and vacuum water control, insulation and per-cycle metering, then repairability, service life and material recovery. Specify consumption data and support periods in tenders, verify consumption at commissioning, and compare bedpan WDs and macerators with site data.

Sources

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