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Whatever happened to the copper in brake pads? Part 2 of 2

Updated: Apr 25, 2022

It all started with a phone call from Stanford Law School in mid-1995…

Fast forward some 15 years from 1995, during which a collaborative effort of fact-finding was pursued by all parties involved. In 2010 the California State Senate passed a bill, SB346, by Senator Kehoe.

Following current regulatory guidelines for heavy metals and asbestiform in 2010, the environmentalist came up with the limitation in Level A. The gradual copper reduction in brake pads through 2025 was arrived at by all stakeholders.

All by weight (“A” Level)

  • Cadmium and its compound: 0.01%

  • Chromium (VI) salts: 0.1%

  • Lead and its compound: 0.1%

  • Mercury and its compound: 0.1%

  • Asbestiform fibers: 0.1%

  • 5% Cu by wt. in brake lining by 2021. (“B” Level)

  • 0.5% Cu by wt. in brake lining by 2025. (“N” Level)

  • Cert. of Compliance by 3rd party required Jan 1, 2014.

  • Leaf Marking would be associated with each level. A one leaf, B two leaves, N three leaves.

Arnold Schwarzenegger, the Republican Governor of California, and an environmentalist at heart, wasted no time to sign the bill into law. The writing was no longer on the wall, it was on paper, signed sealed and delivered! Compliance was underway. Similar regulations were enacted in Washington (SB 6557), Oregon (SB 341 Proposed), and New York (S 1356 Proposed). Enforcement: Civil penalty of $10,000 per violation.

In January 2015 a voluntary Government-Industry Memorandum of Understanding (MOU) was signed. For details, please see

Quoting from Limitation under the MOU, it reads:

“This Copper-free Brake Initiative is a voluntary agreement that expresses the good-faith intentions of the parties and is not intended to be legally binding or create any contractual obligations on any party”

As of September 2021, some 75% of registered brake friction material formulations are ahead of the scheduled 0.5% copper in brake pads, meeting N level.

What is not covered under these regulations are all military and emergency vehicles, i.e., ambulances, fire engines. Race cars, except in California. All off-highway vehicles. All brakes that are immersed in oil or water or enclosed in some form. All drum brakes. All brakes that hold vehicles in a stationary position such as drum-in-hat and truck blocks. And all motorcycles.


While one cannot overlook the importance of historic collaborations between the industry and stakeholders to arrive at this non-binding agreement, one should also consider the tradeoffs and alternatives. Friction material compounders have lost lots of leverage without having the use of copper. Yes, everyone claims to have copper free brake pads available but there are all issues still being dueled over: the performance, noise vibration and harshness, durability, comfort (as in vehicle judder). On the other hand, the compromise between the stakeholders was not exactly one sided. The industry avoided the probability of legal action which would have led to years of litigations and who know how much expenses. Scientists and negotiators replaced lawyers. The salmon industry financial bleeding because of water contamination slowed down with time.

Removing the copper from brake pad formulation helped a specific issue. However, it is not just the copper that is of issue, all other debris generated by brake coupling is now under investigation. It is a bandwagon that just about everyone from the industry, and yes, the environmentalists have jumped on without looking into the possibility of collecting the debris at the source. Yesterday it was copper, today it is brake coupling debris that is being analyzed by all groups. All and all, the fact remains that brake coupling debris is inevitably generated, airborne and ground deposited, and most are washed by stormwater into the water estuaries. What if we could only collect the debris and recycle them to say produce energy via pyrolysis?

Oh, one other thing: aside from a handful of states in the United States, there are no regulations elsewhere outside the United States. The rest of the world keeps on producing brake pads with copper content for all markets other than the USA. Even our neighbors to the South and North, Mexico, and Canada, do not follow suit! Of course, maybe our neighboring countries do not have the same financial burden with their fishing industry as we do in places like Washington and California to name a few. Or, perhaps in Europe they treat the stormwater prior to having it discharged into the water estuary.

The complicated problem of copper in brake pads and its effect on marine life involved many stakeholders across the country. They came from the automotive industry, environmental, and yes, state, and federal government groups. The problem was not exactly solved overnight, and the parties did not see eye-to-eye at first, but science and logic prevailed. Everyone found something in it to sacrifice for a greater good. In the end an historical agreement was reached, and a template collaboration model was born. Why not use this approach to arrive at a meaningful resolution for other seemingly complicated issues such as brake wear debris, tire wear debris contaminants especially microplastics from vehicles? More on those later…

So, coming back to the original question: Whatever happened to the copper in brake pads?

As I take my weather permitted daily walk by Hudson River here in NYC overlooking at the Statue of Liberty, I often pass by armature fishermen patiently waiting by their fishing rod resting over the guardrail. I think of all the hours that Brake Pad Partnership and Steering Committee spent on this project over years. I think of all the support that individuals received from their organizations, both financially and time away from office, only because there was a real problem to be addressed and solved. Less contamination in water, better marine life ultimately leading to healthier human lifestyle.

In researching for these articles, I would like to acknowledge the contributions from Mark Phipps, PhD, Marvin Weintraub, PhD, Kelly Maron, PhD, Steve Brown, and Laurie Holmes formerly with MEMA. Special thanks to Tim Merkle, PhD for having read and reread my part 1 & 2 blogs with patience and constructive comments.

Mohammad Vakili has been in the Friction related technology for over four decades. He holds a BS and MS in Chemical Engineering from U. Mass. He is the Founder and one of the instructors in Brake Academy.
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