Plastics Challenge: Mitigating the Release of Microplastics from Tire Wear

Environment and Climate Change Canada (ECCC) is seeking environmentally acceptable and cost-effective technologies that will mitigate the microplastics pollution from tire wear (also known as tire wear) in Canada.

Prospective applicants should refer to the Innovative Solutions Canada Grant Instructions and Procedures document.

Problem statement

Globally, it is estimated that 6 million tonnes of tire wear particles are released to the environment annually (Selonen et al., 2021; Kole et al., 2017). Microplastics* released from tire wear are becoming recognized as a significant source of environmental pollution that requires further research and innovative solutions. Once released into the environment, microplastics persist for a long time and accumulate in natural habitats, potentially impacting ecosystem health. The particles from tire wear also have the potential to leach chemical additives and heavy metals into the environment (Wagner et al., 2022; Sieber et al., 2020; Brinkmann et al., 2022). Technological innovations surrounding the prevention, reduction or collection of tire wear particles by targeting tire design or the tire use phase would assist in mitigating the risk to the environment.

*Microplastics are defined as plastic particles (including fragments, or fibers) with a diameter less than 5mm (GESAMP, 2016).

Desired outcomes and considerations

Essential (mandatory) outcomes

The proposed solution must:

• Develop an environmentally safe solution that reduces tire wear particles being released into the environment for at least one vehicle type
• Account for an appropriate life cycle management strategy that will not have further adverse effects on the environment, including an end of life strategy that retains the value of the product in the economy
• Adhere to tire wear standards in line with currently available tire solutions, e.g. ISO 4649:2017 (International Organization for Standardization, 2017) for rubber, vulcanized or thermoplastic tires
• Not eliminate the tire or vehicle use in the proposal design
• Not target off-vehicle capture of tire wear particles/microplastics

Additional outcomes

The proposed solution should:

• Demonstrate reduced release of chemical contaminants into the environment compared to conventional rubber tires
• Develop an environmentally safe solution that prevents tire wear particles from being released into the environment
• Evaluate the applicability of the solution in different Canadian contexts (various associated seasons and environmental conditions/compartments)
• Demonstrate suitability for more than one vehicle type.

Background and context

The Government of Canada is tackling the issue of plastic waste and pollution, including microplastics, through multiple initiatives such as the Ocean Plastics Charter, the Canada-wide Strategy on Zero Plastic Waste and associated Action Plans developed in partnership with the provinces and territories, and through a comprehensive science agenda (Government of Canada, 2022). The Government recognises the importance of innovation in the achievement of zero plastic waste, and through the Canadian Plastics Innovation Challenge program has provided funding to Canadian innovators to develop technologies addressing issues such as microfiber release from textiles and the filtration of microplastics from ship greywater.

The natural environment is widely contaminated with microplastics, and tire wear** is a significant source of this pollution that requires further research (Parker-Jurd et al., 2021). Tire wear particles are considered microplastics due to the use of synthetic polymers in tire composition, the size of the tire wear particles and their physio-chemical properties (Hartmann et al., 2019). Microplastics released into the environment persist for a long time and accumulate in natural habitats, degrading into smaller and smaller particles. These particles have the potential to leach chemical additives (vulcanising agents, antioxidants, plasticisers, etc.), fillers (carbon black, mineral fillers, etc.) and metals into the environment that may negatively affect environment and human health (Wagner et al., 2022; Sieber et al., 2020; Brinkmann et al., 2022).

Tire wear is generated due to friction occurring between the vehicle tires and the road surface during normal use. Several factors influence tire wear rate, such as tire or vehicle characteristics, road surface, driving behavior, maintenance of tires, road traffic and weather conditions (OECD, 2021). While innovations exist in tire composition to decrease tire wear, there are none that prevent the emission of tire particles into the environment. This Challenge is seeking environmentally acceptable and cost-effective technologies that will prevent or reduce tire wear particles from being released into the environment.

Efforts to mitigate the release of microplastics into the environment from tire wear emissions will further advance the Government of Canada’s goal to achieve zero plastic waste by 2030. Moreover, microplastics from tire wear are a global problem and there is opportunity for Canada to demonstrate leadership in addressing the issue.

**Tire wear particles can be generated from laboratory abrasion studies or from road driving (in which case they would include particles both from the tire and from the road surface – also referred to as tire and road wear particles). …

Source: Government of Canada