Dear Recyclebank: I heard a story on the radio about reusing tires, the gist of which was that they are full of harmful chemicals. I think specifically it was stated that they should not be shredded and used for children's playgrounds. I'm wondering if they might outgas some harmful chemicals into the indoor environment, and if they pose a fire risk. Any thoughts on the safety of reusing or recycling tires? –Cathy T.

Dear Cathy: For the unfamiliar, outgassing (or off-gassing) is the release of volatile organic compounds from a material, some of which have been found to be carcinogenic. In the case of tires, these can include benzothiazole, butylated hydroxyanisole, n-hexadecane, and 4-(t-octyl) phenol, per the Connecticut Agricultural Experiment Station. While the effects of these compounds on those who work with rubber have been well-documented, not as many studies have been done on the effects on consumers. However, a number of recent studies have started to examine the safety of using tire crumbs in playground, as well as in athletic fields, flooring, and mulch. In general, only low-level emissions were detected and no immediate risks have been found, but the EPA has recommended further research.

If you do decide to reuse tires, you might want to keep them outdoors so the gasses have a chance to dissipate. Sealing them with plaster or another material can help minimize both outgassing and fire risks. Having them professionally recycled could be even safer, since recycling facilities will have the equipment to handle them properly, though they are likely to be put to the same uses mentioned above. Cities and haulers may collect tires during specialty collection events, and many tire retailers will also accept old tires for proper disposal. Whether you find a way to reuse or recycle tires, it will be better than leaving them in a landfill.

SOURCES
CalRecycle
CT Department of Public Health
EHHI
EPA.gov