Comprehensive Chemical Profiling of Potentially Hazardous Additives in Leachates from Synthetic Rubber Surfacing

Abstract

The widespread use of synthetic rubber surfacing in outdoor sports facilities and children's playgrounds raises concerns about the environmental impact of leachable additives present in these materials. This study aimed to elucidate the chemical composition of potentially hazardous additives released in water and ethanol leachates from three types of rubber surfacing. LC-MS, GC-APCI-MS, and pyrolysis-GC-MS techniques were employed to conduct a comprehensive chemical profiling. By consulting the NIST 20 MS/MS, Pubchem, and NORMAN polymer additive databases, we identified a total of 54 ethanol-leachable chemicals. Noteworthy substances included four phthalate/adipate plasticizers, three phosphate flame retardants, three acyl amides, a rubber vulcanizer, a stabilizer, and a urethane catalyst. Our investigation of the COMPTOX hazard database revealed that the stabilizer, dicyclohexylamine, exhibited potential for acute human toxicity, while the catalyst, dicyclohexylcarbodiimide, demonstrated the potential to cause severe skin damage. Additionally, our search in the ECOTOX database highlighted that dicyclohexylamine could adversely affect waterflea and algae at sub-ppm concentrations. These findings suggest that the leachability of rubber surfacing additives could pose a potential risk to human health and the environment and further research is needed to assess the long-term environmental impacts of synthetic rubber surfacing.