Tire Crumb Rubber and Human Exposure on Synthetic Turf Fields – Review of the EPA/ATSDR Federal Research Action Plan (2019 & 2024)

by | Jul 29, 2026

Executive Summary

In 2016, the U.S. Environmental Protection Agency (EPA), the Centers for Disease Control and Prevention (CDC), the Agency for Toxic Substances and Disease Registry (ATSDR), and the Consumer Product Safety Commission (CPSC) launched the Federal Research Action Plan (FRAP) to study recycled tire crumb rubber used as infill on synthetic turf fields and playgrounds. The goal was to answer a question parents, coaches, and communities had been asking for years: what is actually in tire crumb rubber, and how much of it do people come into contact with while playing on it?

The research was released in two parts. Part 1 (2019) characterized what chemicals are present in tire crumb rubber. Part 2 (2024) measured how people are actually exposed to those chemicals during real play and practice, including a biomonitoring study comparing athletes on synthetic turf to athletes on natural grass.

This is the most comprehensive government-led exposure study on tire crumb rubber conducted in the United States to date, and it is the study most frequently cited in public conversations, and public concerns, about turf safety. Any credible synthetic turf authority resource has to engage with it directly, not around it.

Key Findings

  • Chemicals are present, as expected. Tire crumb rubber contains a range of metals and organic chemicals, and all fields tested positive for bacteria at levels the agencies compared to those commonly found on household surfaces.
  • Actual exposure was measured as low. Across both outdoor and indoor fields, next-to-field air concentrations for most analytes were not meaningfully different from background (non-field) air samples. Some compounds — including benzothiazole and certain PAHs, were measurably higher near the field, and indoor field air concentrations were generally higher than outdoor.
  • Very little of what’s in the material transfers to the body. In simulated biological fluid testing, only a small fraction of metals in tire crumb rubber were bioaccessible (roughly 3% in simulated gastric fluid, less than 1% in simulated sweat and saliva), far below the conservative default assumption of 100% used in early risk models.
  • Biomonitoring found no meaningful difference between turf and grass athletes. In the supplemental biomonitoring study (132 synthetic turf field users compared to 29 natural grass field users), there was no significant difference in urinary PAH metabolite levels between the two groups. Metal levels in blood were consistent with the general U.S. population, with the exception of selenium — a finding the agencies noted was not explained by the field material itself, since selenium wasn’t detected above threshold in the tire crumb or surrounding field environment.
  • Agencies’ own bottom line: across Part 1 and Part 2 combined, the federal researchers concluded that exposures to chemicals from tire crumb rubber during normal play activity “are likely limited.”

Important Limitations

Act Global believes a research review is only useful if it’s honest about what the underlying study does not say. Several limitations matter here:

  • This was not a risk assessment. The EPA and ATSDR are explicit that the FRAP characterizes exposure, what’s in the material and how people come into contact with it, but does not draw conclusions about health risk or set safety thresholds. Exposure data is an input to a future risk assessment, not a substitute for one.
  • Sample sizes were small. The pilot exposure and biomonitoring study involved measurements at only three fields and a limited number of participants. The supplemental biomonitoring study was larger (161 total participants) but still modest relative to the number of fields and athletes nationwide.
  • The study measured typical use, not worst-case scenarios. Conditions like extreme heat, unusually long exposure durations, or non-standard field maintenance were not the focus.
  • Some compounds showed elevated readings that remain only partly explained, including the selenium finding in blood and several compounds with next-to-field air concentrations above background. The agencies flagged these as areas for continued attention rather than closed questions.

Why This Matters

For architects, athletic directors, municipalities, and parents evaluating a synthetic turf project, tire crumb rubber has been one of the most persistent public concerns in the category, and one of the most frequently misrepresented, in both directions. This study doesn’t provide a simple “safe” or “unsafe” verdict, and any source claiming it does is misrepresenting a study that explicitly declined to make that determination.

What it does provide is the most rigorous exposure data collected to date, from real fields under real play conditions, using biomonitoring, not just surface sampling. That data consistently points toward low measured exposure and no meaningful biological difference between turf and grass athletes on the metrics tested. For decision-makers, that’s a meaningfully different, and more useful, starting point than either alarm or blanket reassurance.

Act Global Perspective

Act Global uses tire crumb rubber as one infill option among several offered across our systems, and we think field owners deserve a straight answer on what the best available federal research actually shows, not a marketing summary in either direction.

The FRAP findings are consistent with the exposure characterization research Act Global relies on when evaluating infill options for a given project, and they reinforce why we present infill choice as a genuine tradeoff conversation with each client, climate, usage pattern, maintenance program, and budget all factor in, rather than a single default answer. We think the responsible position is the one the federal researchers themselves take: this research substantially narrows the uncertainty around tire crumb rubber exposure, and it does not close the door on further study. Where the agencies flagged open questions, like the elevated selenium and next-to-field air readings, we think field owners are better served by knowing that than by not.

Related Resources

Access the Original Study

This review is Act Global’s independent summary of publicly available federal research, prepared for educational purposes. Act Global does not host or reproduce the original reports. Readers can access the full findings directly from the source:

This is an Act Global Research Review, an independent interpretation of publicly available peer-reviewed research prepared for educational purposes only. It does not constitute medical, legal, or engineering advice.