Trinity research looks at the environmental impact of hand sanitisers

15 Mar 2022

Image: © singkham/

The research suggests that isopropanol-based sanitising gel is better for the environment overall than alternative hand-washing options such as soap and water.

Researchers from Trinity College Dublin have looked at the environmental impact of hand sanitisers following their increased usage during the Covid-19 pandemic.

The research team noted that all forms of hand-washing can have an impact on the environment. However, a study by the team suggested that certain alcohol-based sanitising gels are better for the environment than other hand-washing methods such as using soap and water.

The study, published in the journal Environmental Science and Pollution Research, noted that the use of these gels increased greatly over the last two years. The World Health Organization recommended frequent hand washing with either soap and water or alcohol sanitiser as Covid-19 began to spread around the world two years ago.

To test the impact these forms of hand-washing can have on the environment, the researchers modelled the impacts of the UK population adopting four different hand-washing practices over the course of a year.

These practices were ethanol-based sanitising gel, isopropanol-based gel, liquid soap with water, and bars of soap with water. The impact of these methods were rated under 16 categories including climate impact, freshwater ecotoxicity, ozone layer depletion and water use.

The results showed that isopropanol-based sanitising gel had the lowest impact in 14 out of the 16 categories. In the climate category, these gels had an impact four times lower than liquid soap hand-washing.

“Isopropanol performed better across nearly all measurements compared with ethanol, except for fossil fuel use,” the study said. “When the results were normalised, fossil fuel use was found to be the least important of the 16 impact categories measured in this [life cycle assessment].”

First author of the research, Dr Brett Duane of Trinity’s School of Dental Science, said hand hygiene has made a “big difference” in slowing Covid-19 transmission over the past two years, but that increased hand-washing practices “do cause significant harm” to the environment.

“Importantly, the work shows that sanitising gels cause less harm than soap-and-water practices, with isopropanol-based gels in particular leaving a relatively lower impact,” Duane said.

“That is useful information for reducing further damage but the work also underlines the need for new gels that are more environmentally friendly.”

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Leigh Mc Gowran is a journalist with Silicon Republic