March 14, 2024

What is CSSD compliant water?

Central Sterile Supply Departments (CSSDs) are responsible for supplying the water to clean medical equipment in hospitals and healthcare facilities. The water produced by CSSDs are used in washer disinfectors and steam sterilisers. Given the eventual use of water produced by CSSDs, there are strict standards regulating the quality and monitoring requirements of this water supply to protect patients.

Over the past decade, two standards have covered the production of CSSD compliant water – AS4187:2014 for hospitals and AS4815:2006 for office-based healthcare settings. The AS4187:2014 standard was amended in May 2019 to update the water quality for washer disinfectors (table 7.2) and outline the required water quality for a dedicated steam generator for steam sterilisers (table 7.4). The amendment also included table 7.3 which outlined the microbial quality for the final rinse water in washer disinfectors.

AS4187:2014 became operational in December 2016 and healthcare facilities were expected to comply with the standards by December 2021. However, due to concerns raised by healthcare organisations, full compliance was initially delayed until December 2023 with departments expected to have a compliance plan in place before this date. With this deadline now passed and some healthcare facilities still struggling with compliance, the Australian Commission on Safety and Quality in Health Care has further delayed the compliance deadline to December 2024 (predominantly an extension of compliance around segregation of clean and dirty processes and the storage of reprocessed devices).

In 2023, a new standard was released (AS5369:2023) which will supercede AS4187:2014 and AS4815:2006. This new standard includes an additional note for table 7.2 that guidance on water quality for washer disinfectors and sterilisers can be found in ISO/TS 5111:2022. The updated standard also includes recommendations for the treatment of hard water which feed CSSD water production systems.

Producing the required mineral content to comply with these standards for washer disinfectors and steam sterilisers is not a complicated process, particularly with current generation bulk demineralization technologies like reverse osmosis and polishing methods such as electrodeionisation and mixed bed resin. The harder part of compliance with the healthcare standards is through the delivery of microbiologically compliant water. Delivering water with the required level of endotoxins can be hard to achieve in practice and it is important to use a water treatment provider that is experienced in achieving this water quality in healthcare settings.


Moerk Water has extensive experience in the design and construction of and delivery of AS4187 compliant treatment systems.  Contact Moerk Water today to discuss how we can help your CSSD achieve compliance.