According to new research published in the Journal of Cleaner Production, biodegradable medical gowns, which are supposed to be greener than conventional versions, instead, produce hazardous greenhouse gases.

The use of disposable plasticised medical gowns - both conventional and biodegradable - has surged since the onset of the COVID-19 pandemic.

As the biodegradable version decomposes faster than conventional gowns, popular wisdom held that it offers a greener option by less space use and chronic emissions in landfills. That wisdom may be wrong.

"There's no magic bullet to this problem," said Fengqi You, professor in energy systems engineering at Cornell University.

"Plasticised conventional medical gowns take many years to break down and the biodegradable gowns degrade much faster, but they produce gas emissions faster like added methane and carbon dioxide than regular ones in a landfill," said You, a senior faculty fellow at Cornell Atkinson Center for Sustainability, adding, "Maybe the conventional gowns is not so bad."

According to the research led by Cornell doctoral student Xiang Zhao, biodegradable gown production poses an additional 11% higher eco-toxicity rate than conventional alternatives.

Adopting landfill gas capture and utilisation processes in biodegradable gown sanitary landfills can reduce 9.79% of greenhouse emissions, life-cycle landfill use by nearly 49%, and save at least 10% of fossil resources by employing onsite power co-generation, the researchers found.

Conventional gowns are environmentally and socially sustainable because they can pose 14% less toxicity to humans, cause 10% fewer greenhouse gas emissions, and are nearly 10% less toxic to freshwater when compared to biodegradable gowns in landfills with extra gas emissions.

Improving the gas capture efficiency above 85% can make biodegradable gowns more environmentally sustainable than conventional gowns.

"It's nice to break down the plastic into smaller things," Zhao said. "But those small things eventually decompose into gas and if we don't capture them, they become greenhouse gases that go into the air."