Sustainable solutions: Searching for eco-friendly ways to decontaminate PPE

COVID-19 is a formidable enemy that has massively impacted our lives, but it has a weakness – it’s highly susceptible to disinfectants.
Sustainable solutions: Searching for eco-friendly ways to decontaminate PPE
Professor Neil Rowan, director of Bio-Science Research at Athlone Institute of Technology

COVID-19 is a formidable enemy that has massively impacted our lives, but it has a weakness – it’s highly susceptible to disinfectants.

Irish researchers are now exploiting this weakness to explore eco-friendly and sustainable solutions to a worldwide problem – the chronic shortage of PPE.

Personal protective equipment (PPE) is vital for preventing or slowing coronavirus transmission in healthcare settings but it’s made for one-time-use only – so the idea of finding ways to reutilise it is very radical.

Now clinicians and researchers from Athlone Institute of Technology (AIT) and NUI Galway are looking at ways to decontaminate PPE so it can be safely and effectively used again.

“The Covid virus is designed to be pathogenic – its structure is really good at being infectious. But that same structure makes it highly susceptible to disinfectant – that’s its Achilles heel,” says professor Neil Rowan, director of Bio Science Research at AIT and adjunct professor of medicine at NUI Galway.

This weakness in Covid-19, he says, is “really lucky” because other pathogens – like the winter vomiting bug – are not susceptible to disinfectants to the same degree.

SAFE SOLUTION

Using the kinds of sterilising technologies conventionally employed in hospitals for PPE is tricky though because PPE is extremely heat-sensitive – so technologies like gamma radiation would destroy it. Rowan, who has worked with these kinds of technologies for 30 years “did a brainstorm and picked the best candidate option for use on PPE” – he came up with vaporised hydrogen peroxide.

“What’s smart about it is that it’s very similar in composition to what you’d use in contact lens solution. Although it’s a very mild decontaminate process, the virus would be readily destroyed very quickly. It’s gentle and it’d allow safe, effective treatment without compromising the material in the PPE.” And because hydrogen peroxide – after about a day post-decontamination treatment – reverts back to water and oxygen, it’s environmentally safe and non-toxic to those working with it. “It doesn’t leave any chemical residual that would be harmful to the environment,” explains Rowan.

The use of vaporised hydrogen peroxide for reprocessing PPE got a boost in the last few weeks when the FDA in the US certified many of the leading sterilisation companies there for using it to reprocess high-tech face masks, e.g. N95 masks. The most complex of all PPE these masks filter out 95% of airborne particles. Now the FDA has approved vaporised hydrogen peroxide to enable up to 20 occasions of re-use of the face masks.

REDUCING WASTE

“Two months ago, when the first reported cases of Covid-19 came to Ireland, we ordered a vaporised hydrogen peroxide system [machine] for University Hospital Galway (UHG). It should be here soon. We predicted the efficacy of using this technology at the same time as it was being approved in the US,” says Rowan.

John Laffey, Professor of Anaesthesia and Intensive Care Medicine at NUI Galway and Galway University Hospitals, is exploring decontamination solutions alongside Rowan. Explaining that the default in healthcare settings over the last 10 years has been to change equipment to single-use, he says the idea of re-using single-use items is new and radical.

“The principle has been ‘it’s better to be safe’ – it’s a cautionary system because of the difficulty of fully decontaminating more complex systems. It’s to avoid risk of infection-transmission but it’s not sustainable long-term – it generates an enormous amount of waste,” he says, adding that – as part of the learning from this pandemic – he foresees increased research into decontamination of single-use items.

There are of course cost and supply issues with PPE, which would make any reprocessing solution a game-changer, helping reduce our dependence on external supplies – particularly if there should be a second wave of Covid-19. We’re currently getting one million units of PPE daily, at a €1b cost to the exchequer. “It’s a huge, mind-blowing cost,” says Laffey.

GLOBAL COMPETITION

The global scale of the virus has seen the world competing for PPE – the essential defence for frontline healthcare workers.

“There are stories of countries hijacking other countries PPE supplies,” says Laffey, adding that things improved somewhat when China went back to producing PPE. “But if there’s a second wave and supply chains from China are cut or diminished, we’d be in a difficult situation.”

The benefits from safe, gentle, eco-friendly decontamination processes would be relevant for single-use equipment beyond the PPE worn by healthcare staff. Laffey points to a respiratory system with an inflatable hood that generates much less aerosol (droplets breathed out by patient) than other systems. “They’re much safer for healthcare staff and other patients so they’re of particular advantage with Covid-19, but they’re in very short supply. They’re made in Italy, and the Italian Government has told companies they mustn’t export them – which is totally understandable.”

Rowan and Laffey have just published a paper in Science of the Total Environment, an international multi-disciplinary journal for publication of original research on the total environment. Their article, ‘Challenges and solutions for addressing critical shortage of supply chain for personal and protective equipment (PPE) arising from coronavirus disease (COVID-19) pandemic – case study from the Republic of Ireland’, looks at how effective decontamination processes would be implemented here.

Currently, the HSE is looking at the area and there’s “a body of work to be done”, says Laffey, around “equipment required, creating space within hospitals for the technologies and putting in place the operating policies needed to use the technologies”.

As just one example of the challenges involved, Laffey points to the fact that the items – like PPE – made for single use would no longer be covered by manufacturer’s insurance beyond that single use. “So there’s an organisational risk issue,” he says.

Rowan says we have the technologies, but they’ll have to be certified for reprocessing of PPE by the competent authority, in Ireland’s case the Health and Safety Authority, which is currently liaising with the National Standards Authority of Ireland to advise on standards.

NEW APPROACHES

Rowan has been examining a suite of sterilisation technologies. They include sodium hypochlorite, a liquid decontaminant – “really effective against Covid-19” – which is under trial in UHG for “very simple, very important PPE”: the respiratory hoods used in ICU. “It means a quick turnaround for [equipment] that’s in high demand.”

He has for a long time been working on a new approach to using UV light – pulsed UV. “It pulses really high-intense flashes of light, equivalent to 50,000 times the intensity of sunlight and it’s delivered at 100 pulses per second. It means we can get rapid decontamination of simple PPE – simple hoods and visors – though it won’t work on the more complex PPE, like face masks.” All of these highly-effective technologies, Rowan says, are environmentally-friendly approaches to the PPE supply challenge.

What the Covid-19 pandemic has shown is that Ireland – and other countries – will not in future be so reliant on single-use medical devices and equipment. This, says Rowan, will involve looking at how technologies already in use to decontaminate medical scopes could be adapted for decontaminating PPE. “Future innovation is likely to look at such critical PPE from a shortage-in-supply-chain perspective that will consider eco-friendly, biodegradable materials [in PPE].”

Many of the lessons that are there to be learned from this pandemic have to do with the environment. And if taken on board, they have the potential to greatly benefit the environment. The idea of changing from single-use medical devices and equipment has this potential too. “There will totally be provision for less reliance on PPE as single-use and this will be with a view to sustainability,” says Rowan.

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