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The rubber recovered from end-of-life tires has found new life in various applications over the years, including new tires, rubberized asphalt, playground surfaces and sports fields. However, those last two applications have been threatened in recent years by allegations regarding the safety of the recycled rubber used in these applications. A recent report published by the U.S. Environmental Protection Agency (EPA) could be a first step toward helping to dispel those allegations, however.

“We applaud EPA for completing Part 1 of the federal research action plan,” says John Sheerin, director, end-of-life tire programs, U.S. Tire Manufacturers Association (USTMA), Washington. “We have and will continue to support scientific research by EPA on synthetic turf fields and infill materials, such as recycled crumb rubber, and we are committed to assisting governments, scientists and other stakeholders conducting further study on this issue,” he adds.

Studying the issue

Gary Champlin, general manager of Champlin Tire Recycling, Concordia, Kansas, and chair-elect of the Institute of Scrap Recycling Industries (ISRI), Washington, says turf markets for recycled crumb rubber experienced a near 30 percent reduction since earlier this decade when unsubstantiated claims that athletes coming into contact with crumb rubber used in these fields experienced health issues, including cancer, began. He adds that while the second part of the EPA study into the issue remains to be released, Part 1, which involved chemical analysis of the material, “was the most important part.”

The Federal Research Action Plan on Recycled Tire Crumb Used on Playing Fields and Playgrounds is a multiagency collaborative effort with several research activities. The Centers for Disease Control’s Agency for Toxic Substances and Disease Registry (CDC/ATSDR) and the EPA’s Office of Research and Development (ORD) conducted tire crumb rubber characterization and pilot-scale exposure characterization studies as part of the effort.

The tire crumb characterization study sought to analyze tire crumb rubber for a variety of chemicals and to characterize field use patterns and maintenance procedures using a structured questionnaire. The objective of the exposure characterization study is to characterize the activity of the users of synthetic fields and measure their exposure to chemicals during their use of these fields.

According to the forward from “Synthetic Turf Field Crumb Rubber Research Under the Federal Research Action Plan: Final Report Part 1 – Tire Crumb Rubber Characterization Volume 1,” which was released in late July, the study “is not a risk assessment; however, the results of the research described in this and future reports will advance our understanding of exposure to inform the risk assessment process.”

Twenty-one community fields and 19 military fields participated in the study. Twenty-five of the fields were outdoors, while 15 were indoors.

While the EPA notes that the report “is not a risk assessment, nor can the information be used to identify a level above which health effects could occur,” the agency adds, “the findings from the report support the premise that while chemicals are present as expected in the tire crumb rubber, human exposure appears to be limited based on what is released into air or simulated biological fluids.”

Looking more broadly

According to the most recent statistics from the USTMA, tire-derived fuel (TDF) continued to be the leading market for scrap tires in 2017, having consumed nearly 106 million tires, which was nearly 10 percent less than in 2015. Cement kilns accounted for 46 percent of this demand, followed by pulp and paper mills at 29 percent and electric utility boilers at 25 percent.

Ground rubber was the next largest market in 2017, consuming nearly 62 million scrap tires, 0.7 percent less than in 2015. Some of this decline can be attributed to the concerns related to sports fields, which accounted for 23 percent of ground rubber demand in 2017, according to USTMA data. Molded and extruded products consumed 38 percent of this material, while playground mulch consumed 24 percent. Asphalt accounted for 12 percent of ground rubber demand in 2017.

Civil engineering applications were the third largest market for scrap tires, consuming roughly 19 million tires in 2017, or 14.9 percent more than in 2015.

Export markets consumed some 6.7 million scrap tires in 2017, which was 7.6 percent more than in 2015, according to USTMA data.

Sheerin says 3 percent of the scrap tires generated in the U.S. in 2017 were exported, largely for use as TDF in Japan and Korea.

“Today, new export markets to India are opening up from both coasts. Time will show if these are sustainable,” he adds. “Energy pricing has a strong influence on export markets, and we have seen exports rising modestly” in 2019.

Jim Meckley is chief operating officer at Tyrex Resources LLC, doing business as CompacTyres, Hamilton, New Jersey, which was formed in 2015 and offers scrap tire collection services to auto dealerships and other generators. CompacTyres operates 14 collection trucks and says it uses patented compaction technology and predictive software to provide increased service frequency and greater value to its clients throughout New Jersey and eastern Pennsylvania.

CompacTyres works with a network of domestic scrap tire processors and with brokerage firms.

Meckley says CompacTyres expects to collect 1.5 million to 2 million scrap tires in the next 12 months and to export 50 to 60 percent of them. Destinations include India, Vietnam and Malaysia. However, he says he would like to reduce the volume of tires CompacTyres exports. “It is impossible that this is the highest and best use.”

Sheerin says USTMA members would like to see all scrap tires enter sustainable end markets. “We are particularly focused on scrap tire markets that advance the circular economy. We see such developments in the area of pyrolysis and rubber-modified asphalt.”

He says more than 80 percent of the scrap tires generated in 2017 went to end markets, exceeding “any other consumer commodities, including aluminum, steel, paper and plastic.”

Champlin Tire Recycling expects to process 5 million tires in 2019 that it has collected primarily from tire dealers in Kansas, Nebraska, Iowa, Missouri and Arkansas, Champlin says. Many of these tires are processed for use in its Back Atcha outdoor furniture. Champlin Tire Recycling also provides turned tractor tire livestock feed bunks and tractor and truck tire sidewalls for silage storage.

Champlin says he finds the best margin in producing the outdoor furniture. “We try to concentrate our efforts in that.”

Forty percent of the tires Champlin Tire Recycling processes goes to TDF and civil engineering applications.

“Coming up with responsible end-of-life solutions has been and will remain the biggest challenge for the industry as a whole,” Meckley says. He adds that scrap tires are a “valuable resource that is being highly underutilized.”

Champlin says he believes scrap tires face the same issue now that they have in the past. “Scrap tires by definition are solid waste in all 50 states,” he says, necessitating permitting for collection and recycling activities.

While Champlin says he is not against these permitting requirements because they offer protections, they also can create challenges for service providers.

For example, while tires have a greater Btu value than coal, he says TDF consumers don’t pay on par with this value. If the market were to rely on this value to move material rather than on regulations, Champlin says, “that should drive pricing to parity with other fuel sources.”

The author is editor of Recycling Today and can be contacted at dtoto@gie.net.