Uncovering the Hidden Threat of Tire Dust: An Opportunity for Innovation
Over the past few months, my deep dive into Tesla has led me to a discovery that few have on their radar - the menace of tire dust. This overlooked issue carries significant implications, and an exciting prospect for startups.
Weight and Safety Concerns:
While the transition from gasoline-powered to electric vehicles is commonly characterized by reducing tailpipe emissions, there's a contrasting perspective to consider. Electric vehicles are typically at least 30% heavier than their internal combustion engine (ICE) counterparts, primarily due to their large batteries. This added mass is a safety issue, as heavier vehicles are more dangerous in accidents. According to this article, “In crashes, the "baseline fatality probability" increases 47% for every 1,000 additional pounds in the vehicle — and the fatality risk is even higher if the striking vehicle is a light truck (SUV, pickup truck, or minivan), according to a 2011 study published by the National Bureau of Economic Research.
Tire Dust and Its Consequences:
Another issue I recently learned about is tire dust. Everytime a driver brakes, accelerates, or turns, the vehicle’s tires shed ultrafine particles. These particles contain a chemical called 6PPD, which helps tires resist cracking and degradation. Unfortunately, when this dust is exposed to ozone, it transforms into multiple other chemicals, including 6PPD-quinone (6PPD-q) which is acutely toxic to fish.
According to one estimate, 78% of ocean microplastics are derived from synthetic tire rubber.
“These fragments are ingested by marine animals — particles have been found in gills and stomachs — and can cause a range of effects, from neurotoxicity to growth retardation and behavioral abnormalities.”
One firm, Emissions Analytics, claims that a car’s four tires emit 1 trillion ultrafine (less than 100 nanometers) particles per kilometer driven. Although no one has studied the impact of these chemicals in humans, one study detected 6PPD-q, in the urine of children, adults, and pregnant women in South China.
This research was summarized in this article by Jim Robbins from Yale Environment 360, last month. Robbins explains,
“Recent studies show that the mass of PM 2.5 and PM 10 emissions — which are, along with ozone and ultrafine particles, the world’s primary air pollutants — from tires and brakes far exceeds the mass of emissions from tailpipes, at least in places that have significantly reduced those emissions.”
Of course, the amount of tire dust emissions is tied to the weight of the vehicles Therefore, heavier EVs produce more tire dust than their lighter gasoline-powered counterparts.
The Need for Innovation
All of this research presents a troubling scenario. It's akin to the tobacco industry decades ago. Back then, the public was unaware of the risks associated with smoking, and people lit up without concern for their health or the health of those around them. Likewise, today, the environmental impact of tire dust from driving is unnoticed.
The question is whether sharing this information, exposing the presence of tire dust and its significant role in ocean pollution and potential human health problems, will be enough to change behavior. Regrettably, the answer leans towards 'unlikely.' To address this issue, we require forward-thinking people to pioneer innovative solutions that can capture, reduce, or even eliminate tire dust.
Alternatives and Strategies:
A brief search unearthed an interesting reference - a report and slide presentation from the UC Berkeley Center for Green Chemistry titled ‘Saving coho salmon: Alternatives for 6PPD in tire manufacturing.’ I highly recommend this material for those interested in this issue.
The report suggests several strategies to address the problem:
Modifying 6PPD to prevent quinone formation.
Exploring alternative antioxidants such as Gallates, commonly used in food preservation.
Using lignin, a wood derivative.
Considering other natural rubber formulations such as Hevea (natural rubber tree), Guayule (a perennial woody shrub) or Russian Dandelion (Taraxagum). And, other natural rubbers possibilities include Chitosan derivatives, Oil palm leaves, and Henna.
Here is a slide from the presentation that summarizes and compares the advantages and challenges of each alternative:
I looked up the authors of the paper to see if they continued to work on 6PPD alternatives. I found that one of the authors, Elliot Rossomme continues to publish in this area though as far as I could tell, he is not working on a startup in this area. One of the another authors is affiliated with ChemForward, a science based non-profit working on safer alternatives to hazardous chemicals. I did not see any mention of 6PPD or alternatives, however they do maintain a database of “SAFER” ingredients that do not present hazards.
Existing Efforts:
Additional research into published patents and scientific literature yielded limited numbers of relevant results. Only a handful of the documents that mention tire dust are focused on collecting, filtering, or eliminating it. An even smaller subset focuses on removing 6PPD from tires or replacing it with an alternative antioxidant.
Here are a few noteworthy examples:
The Tyre Collective, a London based startup devised a wheel-mounted device that collects ultrafine particles using electrostatically charged copper plates. Here’s an article from 2022 providing a high-level overview of their technology, and a link to their patent.
Ford Motors filed a patent on a similar mechanism to capture tire dust in 2017. The inventors explained:
“Data from the Deutsches Umweltbundesamt [German Federal Environment Agency] give cause to expect that exhaust-gas particle emissions in the year 2020 will make up about 18% of all traffic-related fine-dust emissions, in which connection the term “fine dust” denotes the particles having aerodynamic diameters of less than 10 μm. The remaining 82% are emissions caused not by exhaust gas but rather by wear. This shows the increasing importance of the particle emissions not caused by exhaust gas.”
Several years earlier, an individual inventor, Jeffrey Krantz attempted to patent a similar innovation.
There is even a patent from the 1980’s focused on collecting tire dust with suction nozzles. However, this inventor focused on collecting materials that were shed due to friction between the brake pad and the rotary. This includes asbestos, lead, copper, zinc, etc.. According to the patent:
“The invention is designed to collect such fine particles and prevent them from becoming airborne outside the vehicle and thereby polluting the atmosphere.”
In another example, Mann & Hummel, a leading German filtration company, filed a patent application in 2022 that disclosed a filter targeting tire dust removal.
Mann + Hummel Tire Dust Particle Filter from German patent application
Others Approaches:
One solution involved filtering tire dust from roads through the stormwater system.
Major tire manufacturers also attempted to remove 6PPD from tire sidewalls and treads, such as Goodyear Tire's 2004 patent.
Nasa developed a “Shape Memory Alloy”. A futuristic, eco-friendly rubber tire alternative. However, this may contain other materials toxic to fish and humans.
Continental Tire introduced an environmentally friendly tire composed of roughly 35% renewable materials,
“including dandelion rubber, silicate made from rice husk ash and a string of vegetable oils and resins. Another 17 percent is polyester yarn made from recycled PET bottles, reclaimed steel and recovered carbon black.”
Exploring new Frontiers:
While I'm confident other examples and innovators exist, it is abundantly clear that this field is ripe for disruption. The opportunity for startups to pioneer groundbreaking solutions in this uncharted territory is immense. At Future Frontier Capital, with our unique background and our data-driven approach, we're well positioned to support these startups.
Until a few weeks ago, I was oblivious to the problem of tire dust. I'm optimistic that by shedding light on this issue, and building on the efforts of those who've contributed to this conversation, innovative minds will tackle this challenge. Spreading awareness is the initial step towards inspiring change.
__________________________________________________________________
Written by Matt Rappaport. Edited by Rohit Gupta.