White Paper 01 – Synthetic Turf Safety & Performance: A Science-Based Framework

The measurable properties that define a professional-grade synthetic turf system — and how to verify them independently.

“Safe” and “high-performing” aren’t marketing adjectives at Act Global, they’re measurable outcomes, defined by a specific set of testable properties and verified through independent laboratory and field testing. This white paper lays out the complete framework: the ten core metrics that define synthetic turf safety and performance, what each one actually measures, why it matters to athletes and field owners, and how Act Global approaches specification and testing for each.

It’s written for the people responsible for making a real specification decision, architects, engineers, athletic directors, and facility planners, who need substance, not superlatives. Every claim is tied to a named standard or test method.

Download the full white paper (PDF + editable Word), free.

What’s Inside

The ten metrics covered in this paper fall into three practical categories:

Impact & Injury Attenuation. g-max, Head Injury Criterion (HIC), and Force Reduction
Movement & Traction. Rotational Resistance, Energy Restitution, and Vertical Deformation
System Durability & Consistency Over Time. Infill Weight & Specification, Maintenance Cadence, Field Age, and Lifecycle Consistency

Our Approach: Bringing Science to the Surface™

Every metric in this paper is governed by a published testing standard, most commonly maintained by ASTM International Committee F08 on Sports Equipment, Playing Surfaces, and Facilities. Act Global tests every system against these standards through independent, accredited labs, including Firefly Sports Testing, Labosport, and Sports Labs, not internal, self-reported results.

We also believe testing shouldn’t stop at installation. A system that performs perfectly on day one can still degrade unevenly without proper maintenance and periodic re-testing. This paper treats performance as a lifecycle question throughout, not a single installation-day snapshot.

Part I – Impact & Injury Attenuation

g-max, Surface Hardness and Impact Attenuation

Governed by ASTM F1936 (Standard Specification for Impact Attenuation of Turf Playing Systems as Measured in the Field).

Gmax measures how much shock a surface absorbs versus transmits back to the body during impact, expressed as a multiple of gravitational acceleration (g). Lower g-max values indicate a softer, more shock-absorbing surface; excessively high values are associated with increased injury risk on impact.

Gmax is one of the most direct, field-testable indicators of impact safety, and it’s sensitive to installation quality, infill depth, and shock pad specification, not just the turf fibers themselves.

Act Global approach: Every system is tested for Gmax both at installation and on a defined re-testing schedule, since infill compaction over time can gradually raise Gmax beyond its original tested value.

Head Injury Criterion (HIC)

A biomechanical injury metric used across sports surface and equipment testing to model head impact severity.

HIC estimates the likelihood and severity of head injury from an impact, based on the acceleration profile experienced during a simulated fall or collision with the surface. It is a more specific, head-injury-focused complement to Gmax.

Because head impacts carry disproportionate long-term health consequences, HIC performance is treated as a first-tier safety metric, not a secondary consideration behind general shock absorption.

Act Global approach: HIC testing is part of our standard system evaluation, particularly for football, rugby, and other contact-sport applications where head-to-surface contact is a realistic scenario.

Force Reduction

A companion measurement to Gmax, often reported together under the same field and lab test protocols.

Force reduction quantifies the percentage of impact force a surface absorbs compared to a rigid, non-shock-absorbing reference surface (typically concrete). Higher force reduction means more of the impact energy is absorbed by the system rather than transmitted to the athlete’s body.

This metric is especially relevant for repetitive lower-body impact, running, jumping, and landing, rather than single high-energy impacts alone.

Act Global approach: Force reduction data is included in every independent test report, alongside Gmax, so field owners see the complete impact-attenuation picture rather than a single isolated number.

Part II , Movement & Traction

Rotational Resistance, Traction and Release

Evaluated using purpose-built rotational traction testing devices, referenced within ASTM F1551 (Standard Test Methods for Comprehensive Characterization of Synthetic Turf Playing Surfaces).

Rotational resistance measures how much a cleat grips the surface, and, just as importantly, how readily it releases during pivoting and cutting movements. Too little traction increases slip risk; too much resistance is directly implicated in non-contact lower-extremity injury mechanisms, including several documented in Act Global’s Research Library.

This is one of the most engineerable, and most safety-relevant, properties of a turf system, a function of fiber design, infill type, and system construction, not an inherent, fixed property of “synthetic turf” as a category.

Act Global approach: We publish rotational resistance data for every system and treat it as a specification-stage conversation, particularly for sports and athlete populations where the research has flagged elevated risk on certain historical turf generations.

Energy Restitution

Measured as part of comprehensive field performance testing, often alongside g-max and force reduction protocols.

Energy restitution describes how much of an athlete’s energy is returned by the surface versus absorbed, directly affecting perceived speed, fatigue accumulation, and overall playability over the course of a match or practice.

A system with poor energy restitution can measurably increase athlete fatigue over a game or training session, independent of any single-impact injury risk.

Act Global approach: We evaluate energy restitution as part of our broader performance testing, balancing it against impact attenuation, the two properties trade off against each other, and system design has to manage that balance deliberately.

Vertical Deformation, Surface Stability and Foot Support

Evaluated under ASTM F1551 comprehensive characterization test methods.

Vertical deformation measures how much a surface compresses under load and how consistently it returns to its original shape. Excessive or uneven deformation affects foot stability, ball behavior, and long-term surface consistency.

This metric is particularly sensitive to consistency across a field, a system that performs well at a single test point but deforms unevenly across high-traffic zones creates exactly the kind of unpredictable footing associated with increased injury risk.

Act Global approach: We test vertical deformation at multiple points across each field, not a single location, because uniformity across the entire playing surface is the practical safety question field owners actually care about.

Part III – System Durability & Lifecycle Consistency

Infill Weight & Specification

Infill type and depth are specified per system design and verified through field testing and submittal documentation.

Infill provides the weight, cushioning, and fiber support that underlie nearly every other metric in this paper. Infill category (rubber, TPE, organic, coated) and weight/depth directly influence Gmax, rotational resistance, and vertical deformation performance, and heavier infill specifications have been associated with measurably lower injury severity in peer-reviewed research.

Infill is not a one-size-fits-all decision, climate, sport, usage volume, and budget all factor into the right specification for a given field.

Act Global approach: We specify infill type and weight per project based on documented performance data. See our full breakdown in Infill Options & Environmental Considerations.

Maintenance Cadence

Maintenance requirements are specified per system and should be documented in writing at time of purchase, not treated as a general recommendation.

A system that tests perfectly at installation can still degrade in performance and safety over time without a defined maintenance program, grooming, infill redistribution, decompaction, and drainage checks all directly affect the metrics covered throughout this paper.

Neglected maintenance doesn’t just shorten a field’s usable life, it measurably changes g-max, rotational resistance, and vertical deformation, the same properties that defined the field’s safety performance at installation.

Act Global approach: We provide a written, usage-scaled maintenance plan with every installation. Full detail in Maintenance, Lifecycle Consistency & Field Safety Over Time.

Field Age & Performance Degradation

Tracked through periodic re-testing against the system’s original installation-day baseline.

All synthetic turf systems change over time, fiber matting, infill compaction, and UV exposure gradually shift performance metrics away from their installation-day baseline. The rate of that change depends heavily on usage volume, climate, and maintenance quality.

A field’s age alone doesn’t determine whether it’s still safe to play on, its most recent test data does. This is why installation-day certification alone is an incomplete safety picture for any field beyond its first season.

Act Global approach: We build a defined re-testing schedule into every system’s lifecycle plan, so performance data, not assumptions based on age, drives replacement and renovation decisions.

Lifecycle Consistency

An integrating principle across every metric in this paper, rather than a single standalone test.

The central theme of this white paper is that no single test result, taken in isolation, defines whether a field is safe or high-performing. Consistency, across the field, and across the system’s lifecycle, is what determines real-world outcomes for athletes.

Natural grass and synthetic turf both face consistency challenges, just from different sources: grass from weather, wear, and season; synthetic turf from infill migration, compaction, and maintenance quality. A well-specified, well-maintained synthetic system is designed specifically to solve the consistency problem grass cannot fully control. See our full discussion in Synthetic Turf vs. Natural Grass — Why Consistency Matters More.

Act Global approach: We evaluate and report on every metric in this paper together, as an integrated system, not as isolated marketing claims.

Conclusion: An Integrated Framework, Not a Single Claim

No single number on this list, by itself, makes a turf system safe or unsafe, high-performing or low-performing. Gmax without rotational resistance data is an incomplete safety picture. Installation-day testing without a maintenance and re-testing plan is a snapshot, not a guarantee. The value of this framework is in treating all ten metrics as connected parts of one system — because that’s how they actually behave on a real field, under real athletes, over a real lifecycle.

This is the standard Act Global holds every system to, and the standard we’d encourage any organization evaluating a synthetic turf project to hold every manufacturer to, not general safety claims, but specific, independently verified, lifecycle-aware performance data.

Frequently Asked Questions

What metrics determine if synthetic turf is safe?

Ten core metrics, evaluated together: Gmax, Head Injury Criterion (HIC), Force Reduction, Rotational Resistance, Energy Restitution, Vertical Deformation, Infill Weight & Specification, Maintenance Cadence, Field Age, and Lifecycle Consistency.

What ASTM standards govern synthetic turf testing?

Key standards include ASTM F1936 (g-max/impact attenuation) and ASTM F1551 (comprehensive characterization test methods), maintained by ASTM Committee F08 on Sports Equipment, Playing Surfaces, and Facilities.

Does installation-day testing guarantee long-term field safety?

No. Performance properties change over a field’s lifecycle due to infill compaction, fiber wear, and maintenance quality. Periodic re-testing against the original baseline is necessary to confirm ongoing safety performance.

Who is independently testing Act Global’s systems?

Firefly Sports Testing, Labosport, and Sports Labs, accredited, independent labs, not internal or self-reported results.

Related Resources

Get the full white paper as a branded, shareable PDF – plus an editable Word version.

Bringing Science to the Surface™, Act Global

Vincent Garcia

White Paper – Synthetic Turf Safety & Performance: A Science-Based Framework