Drawing on our team at Delve's experience with lateral flow test design, we took apart five common COVID-19 home self-test kits to see for ourselves just how much waste each kit generates—and identify opportunities for a more sustainable product redesign.

By enabling us to efficiently identify and isolate infected individuals, COVID-19 home self-testing kits have played a huge role in helping bring the pandemic under control globally. Developers and manufacturers of these self-testing kits deserve credit for the quick development and delivery of this essential tool in the midst of the global crisis.

With what is hopefully the worst of the COVID-19 pandemic behind us, it is becoming more apparent that the community benefit of all this self-testing has come at a steep environmental price.

Confronting the environmental cost of COVID-19 containment: single-use plastic and other waste in lateral flow tests

Consider the following:

• The Biden administration purchased 1 billion of these tests in January, a figure that equals 11,000 tons of plastic waste in the U.S. alone. To date, the Biden Administration has delivered approximately 350 million free COVID-19 self-tests to households across the US.
• Our analysis of five commonly used COVID-19 self-tests found that they use between 7.5 and 42 grams of plastic each—plastic that often ends up in landfills.
• According to our analysis, depending on the manufacturer, between 55% to 92% of the plastic waste produced by each COVID-19 test is used for packaging, not the actual test.

Arguably, our reliance on single-use plastic materials in the design of the lateral flow tests (LFTs) at the heart of every COVID-19 home testing kit encapsulates the broader challenge we face around sustainable medical device design.

On the one hand, LFTs were intentionally designed to be affordable, accurate, easy to use, and adaptable. 

• They can provide a convenient diagnostic reading at home quickly and efficiently, eliminating expensive and time-consuming visits to a doctor's office. 
• These tests were critical during the pandemic in slowing the spread of COVID-19 and helping secure our community's health. It is no wonder that lateral flow tests are in everyday use worldwide. 
• They are essential for COVID-19 self-testing, over-the-counter home pregnancy tests, and the testing of other infectious diseases, such as the flu and sexually transmitted infections. 

It is no surprise that the global LFT market is expected to grow by 5% a year over the next eight years, dominated by rapid self-testing kits.

On the other hand, we need to acknowledge the environmental cost of these user benefits. 

"There is a great opportunity for manufacturers to take ownership of their product waste streams," says Eric Mackey, Director of Industrial Design at Delve. "At Delve, we often discuss designers' responsibility to ensure we design towards an equitable future on a healthy planet. To me, this means leading the effort to create a safe and healthy future for society and the environment while helping our clients realize the benefits of this approach."

COVID-19 seems to be approaching its endemic phase in the U.S., but the need for monitoring and the demand for self-testing kits will remain high for the foreseeable future. 

Beyond this, self-testing for COVID-19 has normalized at-home diagnostic testing in a way that is sure to impact diagnostic testing for a broader range of medical conditions previously relegated to the clinical environment.

For these reasons, we need a critical retrospective of the decisions made to ensure that environmental missteps do not carry forward into this growing market.

"By interrogating our past work of designing COVID-19 self-test kits, we can learn from our choices concerning the proper application of single-use plastic and the overall efficiency in our use of materials," Mackey says. "Just because these products disappear from our sight after use, we recognize they do not disappear from our lives altogether."

With this challenge in mind, Delve recently did a teardown of five COVID-19 self-test kits commonly used in the U.S. Our goal: to discover just how much overall waste each one generates and identify potential opportunities for waste reduction. 

"We know many of these tests were designed under extreme pressure and the resulting solutions were not ideal; we want to confront this and see what lessons we can learn," Mackey says.

Teardown methodology

For the teardown, we decided to look at five COVID self-tests commonly used in the U.S:

• Flowflex COVID-19 Antigen Home Test, manufactured by Acon Labs, US
• BinaxNOW COVID-19 Antigen Self Test, manufactured by Abbott, US
• QuickVue At-Home OTC COVID-19 Test, manufactured by Quidel, US
• Ellume COVID-19 Home Test, manufactured by Ellume Ltd., Australia
• iHealth COVID-19 Antigen Rapid Test, manufactured by iHealth Labs, a subsidiary of Andon Health, China

How did we score each COVID-19 at-home test kit?

We tore down two sample kits per brand and assigned scores for each brand based on the average of the two sets of measurements. Each brand would receive three component scores and one overall score, expressed as letter grades.

• Materials Score – based on the total weight of materials used in the kit (packaging and test components)
• Test Component Efficiency Score – based on the weight of just the test components, on a per-test basis
• Packaging Efficiency Score – based on the weight of packaging materials, on a per-test basis
• Total Environmental Score – summarizes the first three scores, reflecting the potential for improvement in material efficiency.

A few caveats

A couple of caveats and limitations in our arguably simplistic analysis:

• For a true picture of the sustainability of at-home COVID tests, we would need to do a full lifecycle assessment (LCA), which would study the environmental impacts of each test from “cradle to grave."
• We chose to limit our analysis to physical weights since we do not have full access to the particulars and sustainability of the raw materials or supply chain for these COVID tests. For example, two of the tests in our study are sourced from China – which leads to a significant transportation burden; this factor is not addressed in our study.
• We have not attempted to differentiate between polymers and are placing a premium on the use of paper products over plastic, but each has an environmental footprint that needs to be reckoned with.
• Further, the whole concept of dealing with home medical waste is fraught with complexity, confusion – and opportunity. Some parts of the test kits are clearly recyclable – but responsibly dealing with others is far more ambiguous – a problem common to everything from tampons to Kleenex.

“Building a detailed bill of materials (BOM) is the first step in understanding a product’s environmental impact and identifying opportunities for sustainable innovation," Mackey says. “The practice helps the team identify a baseline to improve upon. The BOM is later assessed, scrutinized, and peer reviewed through more rigorous LCA process that quantifies material life-cycle impact." 

Viewed in this context, we feel that the current teardown analysis, despite its limitations, highlights some directionally interesting and very useful data surrounding the various tests and the implications of decisions made when developing them.

While there are subtle yet important design differences, each LFT kit contains similar components:

• An assay strip in plastic housing

• Buffer solution stored in a plastic container

• Various swabs

• Secondary packaging

When designing for sustainability, of course, the devil is in the details. We decided to use an electronic balance with 0.001g accuracy, calipers, and a ruler, to tear down each kit to its basic components. Then, by weighing each component and measuring its dimensions, we would quantify its environmental impact.

Implications and opportunities for more sustainable product design

“Studying the environmental efficiency of these at-home COVID tests provides a chance to illuminate some of the opportunities—and challenges—of designing in the midst of a crisis,” says Dave Franchino, Delve’s Chief Technology Officer.

Sure enough, the results of our teardown point to a few clear opportunities for designers and manufacturers of COVID-19 self-test kits to reduce plastic and other waste; for example, by reducing the amount of packaging and other components not directly required for testing.

And, in fact, some companies are already developing COVID-19 home testing kits redesigned for sustainability. 

According to Medical Device Network, some companies are focusing on non-plastic devices ranging from simple strip tests (similar to the dip tests health professionals use to test urine) to paper devices.

One London-based studio recently highlighted in FastCompany is developing a rapid test entirely made of paper pulp. Yet another company, SureScreen Diagnostics, is investigating biodegradable polymers.

The purpose of challenging existing COVID-19 self-test designs is not to second-guess decisions made by medical device teams that were working frantically to address a pressing public health crisis. 

Rather, it is part of a natural process designers and engineers use to learn and grow from previous experiences, Franchino says.

"It also serves as a superb introspective test case for the value of investing in a portfolio of sustainable materials, design tools and manufacturing methods that designers can have available to then draw upon—not only in the event of a crisis but in the course of our every-day work."

The more we can make the application of responsible design principles second-nature, the more likely we are to serve as responsible stewards of the earth’s resources and ensure our design solutions refine and evolve for the better of users and society.