Crumb Rubber Fact Sheet
Much of the information listed on this page will reinforce what the recycled rubber industry has known for years: our products are not just sustainable for the environment, but also for the health, safety and well-being of all those that come in contact with, and us, them.
A number of states and associations have conducted tests and released reports to help clear up any misconceptions related to recycled crumb rubber safety. All of the results confirm that our products, made from recycled crumb rubber and buffings, is safe for the environment and for the communities and people that use them. It has been shown that exposure to products with recycled crumb rubber and buffings poses NO risk to adults, children or pets.
Recycled crumb rubber and buffings does not pollute the earth or water tables. It does not contain harmful levels of lead and the material concentrations that make up tire rubber are far below levels that are considered harmful as noted in the below findings. The EPA performed tests on recycled crumb rubber and buffings and published results in December 2009 on their website in an article titled, "The Use of Recycled Tire Materials on Playgrounds & Artificial Turf Field." The summary of results stated, "On average, the concentrations of components monitored in this study were below levels of concern."
Similar conclusions have been established on the international front. In a study on the assessment of health risks from recycled crumb rubber and buffings the Norwegian Institute of Public Health and the Radium Hospital stated, "On the basis of estimated exposure values and the doses/concentrations which can cause harmful effects in humans or in animal experiments, it is concluded that the use of crumb rubber does not cause any elevated health risk. This applies to children, older children, juniors and adults." The International Federation of Association Football in Switzerland also states that Epidemiological studies conducted by the Health Effects Institute, The World Health Organization and other investigators do not implicate tire wear particles in ambient air as contributing to human health effects (respiratory and cardiovascular diseases).
We want people to know that recycled rubber is safe. Over the past two decades there have been more than 50 independent studies completed on recycled rubber and all have all had one thing in common – all have found no connection between recycled rubber and any health issues for children and adults. But don’t let us make that conclusion for you – read what the experts have concluded, as we invite you to learn more about recycled rubber, and the wonderful benefits of using it: http://www.recycledrubbersafetycouncil.org.
Overview of the Study
The Department of Environmental Conservation (DEC) is conducting a study due to recent public health and environmental concerns about exposure to chemicals found in the crumb rubber portion of fields. The study is designed to address: the release of compounds into the ground or surface waters, release of compounds to the air under different temperature conditions, and temperatures and heat measures recorded at field surfaces.
The DEC study includes measurement of the temperatures above nearby grass and the air upwind of these fields. Testing nearby grass will provide a comparison of the temperatures on grass fields. We are testing the air upwind of the field because many of the chemicals present in the surfacing may also be present in urban air and soil.
What chemicals are in the crumb rubber?
Crumb rubber is made from recycled tires. Tires are manufactured from natural and synthetic rubber along with many chemical additives, including zinc, sulfur, black carbon, and oils that contain polycyclic aromatic hydrocarbons (PAHs).
How can people be exposed to the chemicals in the crumb rubber?
To date, studies on the release of chemicals from crumb rubber have reported very low concentration of chemicals. Although exposure to these chemicals is expected to be low, the primary ways that people can potentially be exposed include:
- Incidentally ingesting small amounts by putting fingers in the mouth or not washing hands before eating or after playing on the fields
- Breathing in small particles of crumb rubber or vapors released from the fields
- Consumption or exposure to ground or surface waters that have potentially been impacted by leaching of chemicals from these surfaces, though no known link to this type of contamination has been found to date.
Have any studies shown health effects with exposure to crumb rubber chemicals?
Recently, the New York City Department of Health and Mental Hygiene (NYCDOHMH) commissioned a private consultant to conduct an extensive review of the literature, focusing on the release of chemicals, potential exposures and health effects related to surfacing. They found eleven human health risk assessments that evaluated exposure to chemicals in crumb rubber. Although each assessment used different approaches, they all had similar conclusions - exposure to the chemicals in crumb rubber is likely to be very small and unlikely to increase the risk for any health effect.
What is the purpose of the DEC study?
DEC is conducting this study to assess the issues raised by the public and to address a number of data gaps that have been identified based on a review of existing studies. The NYCDOHMH report addressed data gaps and provides recommendations including:
- The need for ambient air measurements of chemicals potentially coming from new and older outdoor surfaces, since most of the data reported in the literature comes from indoor surfaces not exposed to sun, rain, and extreme heat
- The need to obtain background levels of chemicals which normally exist in ambient air to provide comparative data on exposures related to urban environment.
DEC will also conduct heat stress measures since there are few published reports that quantify heat stress from the use of these surfaces. Also, some reports indicate the surface temperatures of these fields are very high. Finally, DEC will be studying the release of chemicals from these fields during rain events and the release of chemicals from the crumb rubber in a laboratory setting under varying temperatures and acid rain conditions.
Where can I get more information?
For questions about the study plan contact Ly Lim at DEC: 1-518-402-8706
For health-related questions, contact the Bureau of Toxic Substance Assessment at the New York State Department of Health (NYSDOH): 1-800-458-1158
To learn more about crumb-rubber, see the NYSDOH fact sheet. A link to this fact sheet is available in the Offsite Links section of this page.
Read the NYCDOHMH literature review report. A link to this report is available in the Offsite Links section of this page.
AIJU Researches On The Best Properties Of Playground Surfacing
Rubber surfacing is an environmentally sustainable product, as a high percentage of recycled rubber from tires no longer needed is used in the manufacture of this material. This kind of material is perfect for playground surfacing, due to its impact mitigation properties in case of falling from playground equipment, such as swings, seesaws, slides, etc., as it is an accessible surface easy to maintain.
This surfacing and these applications are relatively new, that is why it is necessary to improve control over them. In fact, an adequate control of their properties increases quality, safety and durability, thus improving the competitiveness of the product in the market.
For all these reasons, AIJU is developing an R&D project awarded and funded by the Institute for Small and Medium Industry of the Generalitat Valenciana (IMPIVA) and co-funded by FEDER funds, “Children’s Playgrounds: correlation between physicochemical parameters and the high-impact capacity of surfacing. Requirement guide for the business sector—SAFESURFACE,” aiming to research on and be aware of the current offers of rubber surfacing located and installed mostly in the playgrounds of our towns, as well as analyse the potential impacts or factors (positive or negative) associated with the use and location of these products.
The analysis of this data will help us, on the one hand, assess how appropriate is the market for this kind of products and, on the other hand, establish a series of recommendations for synthetic surfacing manufacturers, thus offering them solutions to develop coatings with a higher high-impact capacity, higher durability and a lower manufacturing cost, thereby offering a greater guarantee of safety.
In this project, with an expected duration of two years (2010-2011), we will identify and select those factors in design that can affect the high-impact capacity. This property is the only feature regulated through technical standards due to its significant impact on the number of serious accidents at playgrounds: it is estimated that 70 percent of accidents happen due to the poor condition of the surfaces.
AIJU Technological Center Specialised in Child Safety
The Research Association of Toy Industry and Allied Workers (AIJU) was established in June 1985. Located in Ibi, in Alicante, Spain, AIJU is a non-profit association focused on researching, developing and improving the quality and safety of children’s products. Accredited for toys since 1989, the laboratory is currently increasing accreditations; it is the first laboratory accredited by ENAC for testing toys, childcare products, playgrounds, play equipment and playground surfacing and materials in contact with food. Besides, AIJU is an Inspection Institution accredited by ENAC for playgrounds.
One of the main objectives of AIJU is to help the children’s products industry to improve its competitiveness, advising on educational and developmental aspects of children and new needs and social situations related to them, their welfare and the products intended for use by them.
AIJU is the only European center specialised in all aspects of children’s products, from research of raw materials, product design or safety assessment to pedagogy and child development studies in relation to children’s products.
Intergrated Waste Management Board
Produced under contract by: Office of Environmental Health Hazard Assessment (OEHHA);
In response to the California Integrated Waste Management Board’s (CIWMB) need to better understand the potential health risks to children using outdoor playground and track surfaces constructed from recycled waste tires, the Office of Environmental Health Hazard Assessment (OEHHA) conducted the following studies.
Evaluation of toxicity due to ingestion of tire shreds based on the existing literature:
Overall, we consider it unlikely that a onetime ingestion of tire shreds would produce adverse health effects. This risk is well below the di minimis level of 1 x 10-6 (one in one million), generally considered an acceptable cancer risk due to its small magnitude compared to the overall cancer rate (OEHHA, 2006).
Evaluation of toxicity due to ingestion of tire shreds based on gastric digestion simulation:
All exposures were at or below the screening values suggesting a low risk of non-cancer acute health effects. This risk is considerably below the di minimis risk level of 1 x 10-6 (one in one million), generally considered an acceptable cancer risk due to its small magnitude compared to the overall cancer rate (OEHHA, 2006). In summary, serious non-cancer health effects are not expected following a one-time ingestion of tire-derived shreds or crumb by a child. *In many cases the exposure due to ingestion of tire shreds is much lower than the average daily intake of chemicals (such as but not limited to (arsenic, cadmium, lead, benzene, trichloroethylene, aniline, naphthalene).
Evaluation of toxicity due to chronic hand-to-surface-to-mouth activity:
Assuming ingestion of the chemicals via chronic hand-to-mouth contact, exposures were below the corresponding chronic screening values, suggesting a low risk of adverse non-cancer health effects.
Testing for skin sensitization by playground surfaces made of recycled tires:
No sensitization was observed, suggesting that these surfaces would not cause skin sensitization in children, nor would they be expected to elicit skin reactions in children already sensitized to latex. Thus, SBR tiles, SBR crumb and EPDM tiles were considered not to be contact skin sensitizers. These results suggest that playground surfaces made of recycled tires do not constitute a skin sensitization risk to children.
Evaluating the potential for damage to the local environment and ecology:
Following a fire in a playground surface made of chipped tires from under the playground contained a low risk to the local
ecology. The air above the burn site was judged by U.S. EPA to pose no health risks to clean-up workers, and the soil/rubber mixture removed from the site was judged not to be hazardous waste, and could therefore be deposited in a designated class III waste facility.
It is unlikely that the use of shredded tires in outdoor applications such as playground surfaces would result in the leaching during rain events of high enough concentrations of chemicals to cause such effects. Further, shredded tires used in applications above the ground water table, as is the case for playground surfaces, produced no toxicity in sentinel species. Considering all the data, it seems doubtful that recycled tire rubber in outdoor applications such as playground surfaces releases high enough levels of chemicals to cause toxicity to animals and plants living in the vicinity.
Evaluation of potential injury from falls on playground surfaces made of recycled tires:
Nationwide, up to 80 percent of serious playground injuries are the results of falls to the surface (Tinsworth and McDonald, 2001). In some instances impact-absorbing surfaces such as wood chips, sand, rubber tile/mats and rubber shreds were effective at reducing injuries from falls compared to hard surfaces such as asphalt, cement, turf and dirt (Chalmers et al., 1996; Mott et al., 1997; Mowat et al., 1998; Norton et al., 2004b). An epidemiologic study by Mott et al. (1997) found that playgrounds with “rubber surfaces” (rubber surface type not specified) performed better.
HIC values were not affected by the age of the rubberized surface, either during the first 2-3 months following installation or during the first two years. These data point out the importance of testing the impact attenuation of rubberized playground surfaces to ensure that they meet the safety standards already in place. Theoretically, failure and potential injuries could be prevented with better installation practices by contractors who had placed rubberized material too thin. This represents a missed opportunity for prevention of playground fall injuries, which are estimated to be in the thousands and which include serious trauma such as brain injury. In addition, the unitary rubber surfaces are expected to be long lasting, with advertised useful lifetimes of 5-10 years or more.
Waste tires are being used increasingly as a primary component of children’s playground surfaces and running tracks. In addition to the benefits of recycling, playground surfaces made from recycled tires have the potential to reduce child injury due to falls in the playground. CIWMB provides grant funds to schools and city recreation departments to construct outdoor playgrounds and tracks using recycled waste tires.
The US CDC (2005) estimates that it cost 1.2 billion dollars to treat playground-related injuries in the United States in 1995.
* If 10 percent of these injuries occurred in a state, then approximately 120 million dollars were spent in this state. Since approximately 80 percent of these injuries resulted from falls (Tinsworth and McDonald, 2001), then reducing the injury rate from falls by only 10 percent has the potential to save almost 10 million dollars in a state. An accompanying reduction in injury severity would save even more.
Advantages: very low maintenance and easy to clean; consistent shock absorbency – year round; does not harbor foreign objects; does not readily support microbial growth; not subject to displacement during children’s play; accessible to the disabled; good footing; very low life cycle costs; unattractive to dogs and cats as a place to defecate; cannot be swallowed by children. Disadvantages: high initial installation cost.
Substances released by recycled tires:
Tire shreds released lower concentrations of volatile organic compounds (VOCs) than metals. In the Chang et al. (1999) study of rubberized athletic tracks, the emission of volatile organic compounds decreased with time, so that after about two years the levels at breathing heights were near background.
ASTM: American Society for Testing and Materials International
CDC: Centers for Disease Control
CIWMB: California Integrated Waste Management Board
EPDM: ethylene propylene diene monomer
U.S. CPSC: United States Consumer Products Safety Commission
U.S. EPA: United States Environmental Protection Agency
VOC: volatile organic compound
Chalmers, D., Marshall, S., Langley, J., Evans, M., Brunton, C., Kelly, A. and Pickering, A. (1996). Height and surfacing as risk factors for injury in falls from playground equipment: a case-control study. Injury Prevention 2: 98-104. Chang, F., Lin, T., Huang, C., Chao, H., Chang, T. and Lu, C. (1999) Emission characteristics of VOCs from athletic tracks. J. Hazard. Mater. A70: 1-20. Mott, A., Rolfe, K., James, R., Evans, R., Kemp, A., Dunstan, F., Kemp, K. and Sibert, J. (1997). Safety of surfaces and equipment for children in playgrounds. Lancet 349: 1874-1876. Mowat, D., Wang, F., Pickett, W. and Brison, R. (1998) A case-control study of risk factors for playground injuries among children in Kingston and area. Injury Prevention 4: 39-43. Norton, C., Nixon, J. and Sibert, J. (2004b) Playground injuries to children. Arch Dis Child 89: 103-8. Tinsworth, D. and McDonald, J. (2001) Special study: injuries and deaths associated with children’s.