How to make lateral flow tests more sustainable

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efore 2020, ‘lateral flow test’ was not a phrase in the average person’s vocabulary. Although LFTs had numerous applications – most notably home pregnancy tests – it wasn’t until the pandemic that widespread self-testing took hold.

For the first time in history, millions of people every week were receiving an LFT kit in the post and performing their own diagnostic procedures at home. Since the start of the pandemic, two billion tests have been provided in the UK alone, with delivery capacity peaking at 900,000 kits a day.

Not only was this an immensely valuable aspect of the pandemic response, but it was also a turning point in the way diagnostics are understood. According to ResearchAndMarkets.com, the global LFT market is set to grow by 5% a year over the next eight years, dominated by rapid self-testing kits. Covid-19 testing kits will remain part of the picture, along with tests for other infectious diseases like influenza and STIs.

Interviewee job titles are as follows:

Brennan Miles, Managing Consultant – Drug Delivery, Team Consulting

Alastair Willoughby, Head of Mechanical Engineering Group, Team Consulting

Liz Thorn, Head of Diagnostics, Team Consulting

Matt Morris, Sustainability Lead, Cambridge Design Partnership

Dan Howarth, Head of Diagnostics, Cambridge Design Partnership

While this is good news from a community healthcare perspective, it hasn’t escaped users’ notice that all this plastic is bad for the planet. Each LFT kit contains an assay strip in plastic housing, buffer solution (also in plastic), various swabs and plenty of secondary packaging.

In the absence of any major recycling schemes, the majority of these components will end up in landfill, or incinerated. This has become a talking point on social media, with users expressing dismay at the environmental implications.

“Consumers are increasingly intolerant of designs with excessive amounts of single-use materials when there’s no environmentally friendly way to process them after use,” say Matt Morris and Dan Howarth at Cambridge Design Partnership. “It's not that people are deterred from using LFTs, but they want better options.”

They add that many LFTs pose an environmental hazard, particularly those the UK government chose for Covid-19 testing.

“We need to find ways to reduce the carbon footprint and risk of pollution from daily-use products like these over the next five to ten years if we're going to achieve globally agreed sustainability goals,” they say. “However, we must balance this action against the environmental, social, and economic hazards of global pandemics.”

So how unsustainable are LFTs really? Brennan Miles, Alastair Willoughby, and Liz Thorn of Team Consulting remark that, while plastic waste is the most visible part of the equation, we should also consider their carbon footprint. Most of this is likely to come from the manufacturing and distribution ends of the lifecycle.

“This is particularly true for those which during the pandemic were rapidly shipped around the world by plane – which is significantly more impactful than slower seagoing routes,” they say. “Long-term localised manufacture may have a significant positive impact.”

On the flip side, the carbon footprint involved in shipping the LFTs should be balanced against the carbon footprint of leaving the house. Travelling to a GP or testing centre, especially by car, can actually be much worse for the environment. In fact, the Sustainable Healthcare Coalition has estimated that one LFT has around 5% of the carbon footprint of a single GP appointment.

The plastic waste may be a little harder to justify. In April, Cambridge Design Partnership conducted an analysis to quantify the true scale of the problem. They found that each test produced 12.3g of plastic waste, two-thirds of which was due to the test components and a third of which was due to packaging.

“We were surprised by how much of the impact came from packaging and other components that weren't directly involved in the test, so are easier to change,” say Morris and Howarth. “We were also surprised to find that, when you multiply the small impact from one test by the massive number of tests done in the UK, the total is significant.”

According to the BBC, the UK’s LFT programme to date has produced enough plastic waste to fill 200,000 bathtubs or 19 Olympic-sized swimming pools.

So how might LFTs be redesigned to make them more sustainable? Team Consulting think the simplest win would be to reduce the plastic in the test strip casework. Manufacturers could also cut down the packaging content and eliminate any unnecessary accessories (like separate buffer and extraction tubes, for instance).

“It was interesting to see the differences in approach taken by different companies in producing the NHS distributed packs,” say Team Consulting. “Some used packaging that doubled up as a buffer holder, while some used a custom plastic part to hold the buffer. Some interesting case studies in this area are to be expected!”

During the course of the pandemic, the UK government did work with manufacturers to make changes – the swabs were shortened and the plastic caseworks were shrunk down. However, there may be ways to do better still without too great an investment. Among other suggestions, Morris and Howarth recommend removing the waste bag, adding more tests into a pack and packing the test strips together in a single foil pouch.

“There’s also scope to redesign the test strip assembly,” they say. “Manufacturers are already offering modular assemblies where more robust designs of nitrocellulose test strips are placed in reusable caseworks.”

Eliminating plastic entirely might prove more complicated – though that doesn’t mean it’s out of the question. As Team Consulting explain, there are companies working on non-plastic devices, ranging from a simple strip test format (much like the dip tests GPs use for testing urine) to paper devices. Others, such as the British company SureScreen Diagnostics, are moving towards biodegradable polymers.

However, major changes to the materials will likely require a lot of re-testing and validation. There will be significant costs involved, in the form of R&D, new tooling, and new assembly machinery (technologies like 3D printing may go some way towards bringing these costs down).

On top of that, the overall lifecycle, including shipping, needs to be factored into the equation.

“The challenges to changing material will be shelf life – will the test still work in the same way with the same accuracy in two years’ time?” says Liz Thorn. “Also the robustness of the material – can a paper product maintain its integrity after a sample has been applied or is there a risk it could fall apart?”

Morris and Howarth think that, over the longer term, we’ll see a push towards a comprehensive redesign. This will not be cheap, but it could end up being worth it if demand for LFTs stays high. It could also place the brand at a competitive advantage, as the self-testing revolution continues and purchasing power shifts to the consumer.

“Even when a product performs an important role, people demand more effort to improve its sustainability,” say Morris and Howarth. “We can expect to see efforts increase in other high-volume healthcare products used directly by consumers, for example, medicines and injector pens, as manufacturers respond to this trend.”

Main image: Steve Allen / Shutterstock.com