Can Coconut Fibre Help Clean Indoor Air? What Botanical Biofiltration Research Shows

Natural fibres are increasingly being studied not only as structural or horticultural materials, but as functional media inside active indoor-air systems. A 2026 study tested coconut fibre and kenaf fibre in an active botanical indoor air biofilter (BIAB).

1. This was an active system—not simply a pot plant

The prototype used mechanical airflow through a two-stage botanical filtration arrangement. Contaminated air moved across plants and growth media and then through evaporative media. That distinction matters: the results should not be interpreted as evidence that ordinary indoor plants or loose coconut fibre will produce the same effect without an engineered airflow system.

2. Coconut fibre performed strongly for PM10 in one tested configuration

Under the study conditions, pure coconut fibre with plants reached a single-pass PM10 removal efficiency of 85.70% at high airflow. A 30:70 coconut–kenaf mixture reached 88.71% PM10 removal at medium airflow without plants.

3. PM2.5 results favoured a fibre blend

For PM2.5, a 50:50 coconut–kenaf mixture achieved 82.51% single-pass removal at low airflow without plants and 79.61% with plants. The result is commercially interesting because it shows that fibre composition and airflow configuration can be as important as the presence of vegetation.

4. VOC behaviour was different

Pure kenaf delivered the strongest VOC results in the reported tests, while botanical elements contributed more clearly to VOC removal at lower airflow. This is useful because it prevents an oversimplified “coconut fibre removes everything” conclusion.

5. Where a future commercial pathway could emerge

Potential users could include developers of active green walls, biophilic building systems, indoor-air-quality equipment and sustainable HVAC pre-filtration concepts. However, commercial adoption would require long-duration testing, microbial and moisture control, fire-safety assessment, maintenance protocols and performance validation outside the laboratory.

6. Why this is a useful coir story

Coir is usually sold by grade, length, cleanliness and application. Research like this suggests a future market in which fibre is selected for controlled porosity, airflow and interaction with biological systems. That is a higher-specification conversation than selling coconut fibre simply as a commodity.

7. What the research does not prove

The reported percentages belong to a specific prototype and operating conditions. They are not universal removal rates for coconut fibre, and they do not establish that commercially available coir products are certified air-purification media.