EPA Issues First Status Report on Crumb Rubber Studies

January 20, 2017

The U.S. Environmental Protection Agency has issued its first status report on the agency’s joint investigation (with the ATSDR, CDC and CPSC) into possible hazards of playing on synthetic turf crumb rubber playing fields. The investigation resulted from media stories and Congressional inquiries following reports of soccer players with cancer and claims that carcinogens in crumb rubber could endanger field users.

The 120-page status report largely provides updates on activities undertaken to date but does not provide any findings or outcomes. Since the study initiation, the study team has:

  • Held meetings with five industry trade associations, several synthetic turf companies and professionals, one academic institution, and five non-profit organizations; 
  • Toured five tire recycling facilities and observed a field infilling; 
  • Sampled crumb rubber from nine recycling plants and 40 fields; and 
  • Developed a literature summary and “data gaps” analysis. 

An exposure assessment portion of the study will not occur until spring when activities on fields increases and the study team can assess routes of exposure and types of exposure-related activities.

The literature and data gap analysis is perhaps the most significant portion of the status report. The appendix contains a lengthy summary of the 88 studies currently existing that address potential health risks of crumb rubber exposure. The summary includes a very useful “capsule” findings list from most of the studies, the vast majority of which find no reason for concern with crumb rubber fields. The many studies already conducted cover “exposure, toxicity, and human health risk to children and athletes,” “occupational exposure and risk,” “ecological toxicity and risk,” off-gassing, and several other subjects. Reading the appendix summary gives the impression that crumb rubber is a well-studied substance, and review after review has given it a clean bill of health.

The “data gaps” analysis, in contrast, identifies a lengthy list of identified gaps in the current literature, some of which presumably the investigation will attempt to fill in. The gaps, as summarized on p. 17 and in Table B-12, often focus on “small number of samples” in some studies and the lack of investigation of the wide range of chemicals that may appear in crumb rubber, and repeatedly characterize the existing 88 studies as “limited.” The extent of the gaps identified will likely provide discussion points for the activists who oppose crumb rubber use, and may mislead the reading public into thinking the existing set of studies is very limited or poorly performed. Despite the data gaps found by the study team, the actual studies provide strong conclusions regarding the lack of health effects. Misleading reports about alleged data gaps should not be used to create unnecessary concerns over safety risks with no demonstrated scientific merit.

EPA expects to complete the research in 2017 and potentially issue updated reports during the year. Activities this year will include analysis of the crumb rubber samples collected from recycling plants and fields; an exposure characterization based on player observation and measurements; a CPSC-sponsored playground focused study; and an exposure measurement study to identify methods for measuring actual exposure. It does not appear that the study team will address the most critical issue, measuring and documenting the extent of actual exposure to field users from any potentially hazardous substances in crumb rubber – prior studies have performed such measurements and almost without exception found levels below detection limits or well below identified hazardous levels.

Meanwhile, the California Office of Environmental Health Hazard Assessment (OEHHA) continues on its 3-year study with a focus on identifying chemicals that may be released from synthetic turf from indoor and outdoor fields throughout California, and on estimating exposures to users of synthetic turf fields. OEHHA has convened a Synthetic Turf Scientific Advisory Panel for their study, with the second Advisory Panel meeting scheduled for March 2017.


This alert is jointly authored by Renee Kalmes of Exponent and by William Anderson and Cheryl Falvey of Crowell & Moring. It is the first of a two-part series on crumb rubber that Exponent's health team is producing.