Kiwi Scientists Develop System to Disinfect PPE

A group of Kiwi scientists have developed a potential solution to the more than 25,000 tonnes of Covid-19-related plastic waste that has polluted the oceans in the past two years of the pandemic.

The motivation behind the project came in March of 2020, after the World Health Organisation (WHO) reported a global shortage of personal protective equipment (PPE) which was endangering the lives of frontline healthcare workers treating Covid-19 patients.

Dr Yvonne Anderson

A team led by Dr Yvonne Anderson, a senior lecturer at Auckland University's department of paediatrics, began researching a method for disinfecting PPE for potential reuse.

The team tested UV light and dry heat to disinfect clinical PPE.

"What we found was that whilst UV is effective at inactivating the virus on flat surfaces, it wasn't successful on the irregularities of PPE. So if you think of the masks, you've got straps and the nose bridge and all of those, that's where the UV might not get to,” noted Anderson.

"But what we did find is that with dry heat, complete virus inactivation was achieved at 65 degrees for 30 minutes or 70 degrees for 15 minutes."

The most recent stage of the research project was to build and test a prototype mobile disinfection unit in a shipping container at the Port of Taranaki.

Anderson explained that not all PPE could be disinfected.

"We have a collection process and a sorting process, so any PPE that's visibly contaminated we wouldn't put through the unit, and that's incredibly important in terms of healthcare worker safety.

"After we've sorted it in a pressure room, we then place it into the oven, which is built into the shipping container and disinfect it under our set temperatures and times and then move it through to the sorting process. And again, any PPE that's damaged along the way would get diverted to waste."

Port Taranaki commercial head Ross Dingle said he had been happy to be able to help the team with its innovative project.

"As a border-facing organisation at the frontline of Covid-19, Port Taranaki has had a lot of its own staff and operators within the port utilising PPE, and actually considerable quantities of PPE. So it's really great to have a project like this which allows that PPE to be recycled, obviously that has really positive impacts on the environment and ensures that PPE is available for those who need it. We're absolutely thrilled that this project been a success."

PPE-disinfection unit

Anderson said it was paramount it found ways to mitigate the ever-growing amount of medical waste that went to landfills, or was polluting lands, rivers, and seas.

And as the project had evolved, it found three potential outputs for the unit.

"One was to disinfect PPE for potential reuse and the event of shortages during the pandemic. Two, we could look at disinfecting PPE for safe recycling of the product, and three, we're looking at hydrothermal processes using waste valorization, basically busting PPE waste into water and reducing the amount of waste going to landfill, but also polluting our oceans and seas."

The next step was to transfer the unit to the University of Auckland faculty of engineering,

Yvonne said they managed to achieve a lot in the past 18 months, but there were still questions that needed to be answered.

"Healthcare and other frontline worker acceptability is a key consideration for us with any disinfection solution of PPE and we are committed to prioritising their voice in the wider project.

"Hopefully we'll be able to engage some partners to look at all of the logistics of potential scale and implementation for this unit wherever it's needed."

The project received $1.3 million in funding from the Ministry of Business, Innovation and Employment through the Covid-19 Innovation Acceleration Fund, and a $46,000 grant from the Medical Assurance Society Foundation.

This article was first published by RNZ and has been republished with permission.