Olive-Pit Infill by the Numbers: A Deep Dive Into the Lab Testing
In our last article, we covered why the industry is moving away from rubber crumb infill and what makes a natural, organic infill like olive-pit granulate a genuine alternative. This time, we're going deeper — into the actual laboratory data.
Every claim below comes from independent testing by AITEX (Spain), Labosport (France and Canada) — laboratories used across the synthetic turf industry for compliance testing. Here's exactly what was tested, what the results were, and what they mean for a project.
The standard it's tested against: EN 15330-5
There's no single Australian standard for turf infill materials, so specifiers here — like sporting codes overseas — generally reference international benchmarks. The relevant one for infill is EN 15330-5, the European standard covering everything from particle composition through to toxicology and durability.
Olive-pit infill has been tested against the full requirement set in this standard, and separately against the equivalent US/Canadian frameworks — ASTM F3496 (PAH content) and ASTM F3188 (heavy metal migration) — for anyone benchmarking against North American specs as well.
Toxicity and safety, in the actual numbers
This is the section where vague claims like "non-toxic" and "free from heavy metals" usually get made without any backing. Here's what the lab work actually shows:
- Leachate toxicity: Tested via bioluminescence bioassay, the leachate result came in above 74,000 mg/l. The regulatory threshold for a material to be classed as toxic is anything at or below 3,000 mg/l — so the result clears the safety line by more than 20 times over.
- PAH content: Polycyclic aromatic hydrocarbons are one of the main things regulators scrutinise in rubber-based infills. Olive-pit infill tested at under 1.4 mg/kg under the EU method, and under 0.12 mg/kg under the US ASTM method — both a long way under the 20 mg/kg ceiling.
- Heavy metals: Lead, cadmium, chromium, mercury, zinc and tin were all tested via leaching (EN 12457-4) and migration (EN 71-3) methods. All results sat well under the EU limits — for example, lead at under 0.005 mg/l against a 0.025 mg/l limit, mercury at under 0.00004 mg/l against a 0.001 mg/l limit.
- EN 71-3 — chemical migration: This is the same migration standard used to assess toy safety, and it's relevant here because kids are often the ones sitting, rolling and playing directly on infill. Olive-pit infill passed the Category 3 requirements.
The honest way to describe this: not "zero" heavy metals or PAHs — trace levels are present, as they are in virtually any natural or manufactured material — but tested at a fraction of what regulators allow.
Performance, in the actual numbers
- Drainage: 10,286 mm/h, tested to EN 12616. The minimum requirement is 500 mm/h — so the tested rate is over 20 times the benchmark. In practice, that means no pooling, no mud, and a surface that's playable again almost immediately after rain.
- Dust: Classified "Very Low" under EN 15051-2, the standard method for assessing inhalable dust during handling and installation.
- Surface temperature: Tested under infra-red exposure per EN 15330-5 Annex F, olive-pit infill reached 49.4°C and was classified Class 1 (under 50°C). That's the coolest classification band in the standard — and a genuine point of difference from rubber crumb, which regularly pushes surface temperatures well above it in direct sun.
- Durability: Put through 15,000 cycles of mechanical roller-infill wear testing, plus separate freeze/thaw cycling. In both cases, the material held its particle size distribution and shape classification within the tolerances required by the standard.
- Density and ballast: Bulk density measured at 0.674–0.690 g/cm³, which is what keeps turf fibres upright and resists wind or foot-traffic displacement.
One nuance worth being upfront about: the Energy Return (elasticity) test classifies olive-pit infill as non-elastic (0.29–0.32 Joule). That's a genuine property of a natural, mineral-dense material — it's not designed to be the primary shock absorber in the system. That's exactly why a proper installation pairs it with a dedicated shock pad layer underneath, which is where impact absorption is engineered into the build-up rather than relying on the infill alone.
Why the material behaves this way
None of this is accidental — it comes down to what the infill actually is and how it's made. Olive-pit infill is produced by grinding and sieving milled olive stones — a byproduct of olive oil production — with no chemical treatment at any stage. About 30% of the processed material is fine enough to be sold separately as a byproduct rather than discarded, and the coarser fraction becomes the turf infill.
That simple, chemical-free process is a large part of why the toxicology results come back as clean as they do — there's nothing added in manufacturing for contaminants to come from.
What this means for a spec
If you're specifying olive-pit infill on a project, here's the shorthand:
- Reference EN 15330-5 compliance, plus ASTM F3496/F3188 if the project needs North American-equivalent documentation
- For toxicity, cite the specific results (leachate, PAH, heavy metals) rather than blanket "toxin-free" language — it's more defensible and, frankly, more convincing to anyone reading closely
- For heat performance, Class 1 (<50°C) is a real, tested differentiator worth leading with for schools, pet areas, and anywhere users are barefoot or lying on the surface
- For shock absorption, spec the shock pad layer — not the infill — as the component doing that job
FAQ
Is olive-pit infill actually independently tested, or is this just supplier marketing? All figures above come from third-party laboratory reports — AITEX (Spain) and Labosport (France/Canada) — not from internal or supplier-generated data.
Does "non-elastic" mean it's less safe underfoot? No — it means the infill isn't the layer providing shock absorption in the system. That's handled by the shock pad beneath it, the same way it is in most modern turf builds regardless of infill type.
How does this compare to silica sand infill? Silica sand is also relatively inert, but doesn't offer the same cooling performance or the sustainability profile of a byproduct material — and doesn't carry the same breadth of toxicology testing typically published for it.
