Source: Okos, by Okos Dx (October 1, 2026). AI-generated summary by biochip.com, published . Not independently reviewed.
Key takeaways
- Okos Diagnostics and Helix Biogen Institute found about 20% mass loss in plant-based cassettes after 12 months in sandy soil.
- Conventional plastic control cassettes showed no measurable mass loss or visible deterioration during the same 12-month field test.
- The study does not establish complete biodegradation or the fate of all fragments remaining after soil exposure.
Okos Diagnostics reports that its plant-based housings for lateral flow tests lost about 20% of their mass after 12 months in sandy tropical soil in Ogbomoso, Nigeria. The follow-up work, conducted with Helix Biogen Institute, extends an earlier four-month field study that tracked how the diagnostic cassettes changed in sandy, clayey, and loamy soils. Conventional plastic control cassettes showed no measurable mass loss or visible deterioration over the same period. The results offer real-world evidence that the housing of a rapid test can physically break down under some environmental conditions, although they do not establish complete biodegradation.
What the Team Tested
A lateral flow test is the familiar strip-based format used in many rapid diagnostics, including home tests. Its disposable plastic cassette acts like a protective shell: it holds the test strip in place and makes the device easier to handle, but it also makes up a substantial share of the product's material.
Okos Diagnostics developed plant-based cassette materials intended to reduce reliance on fossil-based plastics while retaining the mechanical properties needed to manufacture and use a diagnostic test. Luis Fernando Sánchez Barrios and Sander Julian Brus, Okos co-founders, co-authored the earlier Frontiers in Lab on a Chip Technologies study with the Helix Biogen Institute team.
From Moisture Uptake to Material Loss
The original four-month experiment found early physical changes in the plant-based cassettes, including moisture uptake, discoloration, deformation, and microbial interaction. The plastic controls changed negligibly. The extended experiment allowed the team to see whether those early changes would continue over a full year.
The 12-month results suggest a sequence similar to a dry sponge left outdoors. A material can initially absorb water and become heavier before its structure weakens enough for material to be lost. The cassettes first showed increases in weight, then measurable loss as cracking, brittleness, and fragmentation became more apparent.
Soil Made a Difference
The soil environment shaped the outcome. Loamy soil produced the greatest early moisture uptake, while sandy soil produced the greatest longer-term mass loss, at around 20%. Clayey soil showed different behavior, reinforcing that breakdown cannot be predicted from a material alone.
That variation is important because conditions outside a controlled composting facility are messy. Moisture, drainage, temperature, soil composition, and microbial activity can all affect how plant-based materials change after disposal. The field work examined those variables under tropical conditions rather than relying only on laboratory tests.
What the Results Do and Do Not Show
The cassettes were designed in accordance with compostability standards including ASTM D6400 and EN 13432. Those standards remain useful for evaluating materials in specified conditions, but a used medical test may not enter an industrial composting system or any managed end-of-life route.
The year-long field study shows physical deterioration and measurable mass loss in the plant-based cassette material. It does not demonstrate that the material completely biodegraded, nor does it determine the fate of every remaining fragment. Further monitoring and material analysis will be needed to map the full degradation pathway.
Why This Matters
Rapid tests support infectious-disease screening and home diagnostics, but their convenience also creates a large stream of single-use waste. Redesigning the cassette targets a visible, material-intensive part of that waste without changing the basic lateral flow testing format.
Proper healthcare waste management remains essential, particularly for used diagnostic devices. Still, the contrast between plant-based cassettes that changed in soil and conventional plastic controls that remained largely unchanged gives researchers a concrete basis for studying lower-fossil-plastic diagnostic designs. Continued field monitoring should clarify how these materials behave over longer periods and across more disposal environments.
Topics: Diagnostics & precision medicine
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