"Hell in a handbasin": infection considerations of four handbasin design features

An Australian-led review compared healthcare handbasin design guidelines across 39 countries with the scientific evidence on healthcare infection risks.

Contaminated basins in health care might put patients at risk and have implications in outbreaks of superbugs, according to a Flinders University-led review published in the Journal of Hospital Infection.

The review — across 39 countries — found substantial inconsistencies between international healthcare design guidelines, leading to calls for better designs to reduce the risk of drug-resistant bacteria occurring, for example the commonly difficult-to-treat carbapenemase-producing Enterobacterales (CPE).

Also, according to lead author Mikaela Todarello, a PhD candidate in Environmental Health at Flinders University, the limited evidence available makes it difficult to determine which design features best reduce the risk of pathogen spread.

“Handbasins need to support effective handwashing without creating avoidable opportunities for pathogens to spread,” Todarello said. “Microbes can build up in taps and drains. When water hits contaminated surfaces, splashing can carry them onto nearby equipment and surfaces.

“There is evidence that handbasin design influences how microbes spread, which means we have a real opportunity to improve these designs and reduce the risk to patients.” As part of the review, the researchers identified several features that deserve closer attention.

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4 design features deserving closer attention

1. Flat basin surfaces — these can allow water to pool and may produce more splashing than curved surfaces, creating conditions that favour microbial growth and spread.
2. Shallow basins — compared with deep bowls, these types of basins have been associated with greater dispersal of small airborne droplets, known as bioaerosols.
3. Drain position — the water stream can strike the drain and generate droplets and aerosol matters when it sits directly beneath the tap, particularly if higher-pressure. To reduce splashing, positioning of the drain away from the water stream should be considered.
4. Water flow and bowl slope — this can change splash behaviour, while how a basin is positioned and used, and whether water pools in it, also needs to be considered.

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“There is still limited research examining how these features work together during everyday use, or which combinations best reduce infection risk,” Todarello said. “We need to close that gap so future design guidelines are based on strong evidence from real healthcare environments.”

The findings of the review point to a practical opportunity to strengthen infection prevention, Professor Harriet Whiley, Professor in Environmental Health at Flinders University, said.

“We ask healthcare workers to wash their hands to protect patients. We should make sure the handbasins they use are designed with the same goal in mind,” Whiley said. “Better engineering could reduce splashing, limit biofilm build-up and prevent contamination from spreading. We can do better, particularly in areas caring for patients who are most vulnerable to infection.”

The review was published open access in the Journal of Hospital Infection (doi: doi.org/10.1016/j.jhin.2026.08.012).

Image credit: M Todarello (Flinders University)