Brake Pad Partnership

Frequently Asked Questions about Senate Bill 346

    • Q: What does SB 346 do?
    • A: SB 346 requires that, in order to improve and protect the state’s aquatic environment, the use of copper in brake pads sold in California be reduced to no more than 5% by weight by 2021, and to no more than 0.5% by 2032. The bill also creates limits and monitoring requirements for other brake pad materials.
    • Q: What do brakes have to do with the environment?
    • A: The answer has to do with two things: how brakes work and what they’re made of. Both disc brakes and drum brakes use brake pads to generate friction against discs or cylinders that in turn slow and stop a moving vehicle. While the car is stopping, the friction also rubs off a tiny amount of the brake pad’s “friction material.” Eventually the brake pads need replacement. Although some of the “friction material” residue (dust) created by braking remains on the wheel, in the brake cylinder, or on the car, the rest goes onto the roadway or into the air.
    • Q: What’s in this dust?
    • A: Brake pads are made from one of several formulas of friction material that are generally classified as “sintered,” “semi-metallic,” “low steel” or “organic ceramic.” Sintered pads have a very high metallic content, normally copper or iron. Low steel and semi-metallic brake pads are so called because of the presence of iron. Organic friction materials generally contain no iron but may contain other metals. Some—but not all—brake pads contain copper and other heavy metals.
    • Q: Why is copper used in brake pads?
    • A: Copper performs several functions: it adds structural integrity to the brake pad material, reduces fade so that brakes remain effective through extended braking events, transfers heat efficiently, and helps brakes be more effective in cold weather. Copper also has properties that help prevent brakes from squeaking and shuddering when they are used, which is very important for car customer satisfaction and keeping warranty costs low. Not all brake pads contain copper. Copper content varies from manufacturer to manufacturer and even among pads made by the same manufacturer, but brake pads for new cars and original equipment replacement pads are generally likely to have higher copper content than other replacement pads.
    • Q: How does brake dust get into our “aquatic environment”?
    • A: Much of the dust that is emitted into the air is blown onto areas adjacent to the roadway, or is washed into the storm drains when it rains. The dust in the air can stay that way for some time and travel until it’s deposited on land. Copper deposited on soil or plants is much less likely to be washed into storm drains than copper that lands on impervious surfaces. Our urbanized areas are largely covered with impervious surfaces (roofs, pavement, etc.), which serve as highly efficient collectors for debris that gets carried into storm drains. In general, anything that gets into a storm drain ultimately flows into creeks, rivers, and marine waters. In most parts of California storm drains flow directly to creeks, rivers, and marine waters without wastewater treatment.
    • Q: Why is copper a problem? What is its effect on the environment?
    • A: Copper is a pollutant of concern in part because of its toxicity to certain sensitive species of algae (phytoplankton) that form the base of the aquatic food web. Most, if not all, of the aquatic species living in California’s near-shore coastal waters and estuaries prey on organisms that are direct or indirect consumers of phytoplankton. Copper also directly damages the sensory capabilities of salmon, making it difficult for them to avoid predators or find their way back to their spawning grounds.
    • Q: How do you know the copper in runoff is from brake pads? What about other sources like pipes, or pesticides, or naturally occurring copper?
    • A: Our studies of San Francisco Bay included estimates of copper releases from a comprehensive inventory of non-brake pad sources, including architectural copper, copper in pesticides applied to land in urban areas, copper in agricultural land applications of pesticides, copper in algaecide treatment of surface waters, copper from pressure-treated wood preservatives, copper in marine antifouling paint, copper in pool, spa, and fountain algaecides, copper in fertilizers, copper releases from industrial facilities, copper in industrial runoff and industrial releases to surface waters, copper in industrial air emissions, and copper in domestic water discharged to storm drains. We also took naturally occurring copper into account. These sources were not as important as brake pads in highly urbanized watersheds. Our studies indicated that copper from brake pads accounted for, in some cases, more than half of the human generated copper coming off of highly urbanized watersheds.
    • Q: Where in California is copper a problem?
    • A: While our studies were focused on protecting San Francisco Bay, municipalities with drainage to several Southern California streams and rivers (Chollas Creek in San Diego County, and Ballona Creek and the LA River in Los Angeles County) have had aggressive Clean Water Act deadlines imposed in the form of TMDLs (total maximum daily loads), in order to attain federal water quality standards for copper. These TMDL standards make the need to address copper in runoff particularly urgent for Southern California, though it is likely that the problem exists in urbanized watersheds throughout the state.
    • Q: Why can’t the copper in stormwater runoff be treated and removed like it is in sewer water?
    • A: Since much of the copper in stormwater runoff is in a dissolved form, the type of treatment technologies that are most commonly retrofitted into storm drain systems—drain inserts that remove trash and other solids—are not effective in removing it. While land-based stormwater runoff treatment systems like infiltration ponds and rain gardens are better at removing copper, widespread installation of these systems would be prohibitively expensive and could be disruptive to established communities, because these systems require significant amounts of land—and that land has to be located near storm drain outlets along creeks, rivers, and beaches. When these facts are combined with the ubiquity of copper in the landscape, it becomes clear that the best and perhaps only way to effectively reduce copper in the state’s waters is to deal with it at its sources. This is what the Brake Pad Partnership seeks to do.
    • Q: What is the Brake Pad Partnership? What has it done?
    • A: The Brake Pad Partnership is a collaborative group of brake manufacturers, environmentalists, stormwater management entities, and regulators that originally came together to understand the impact on the environment of brake pad wear debris. Before the Partnership committed to investing significant state and private resources in technical studies, the Brake Manufacturers Council (BMC) and its members (primarily manufacturers of original equipment friction materials) agreed to introduce reformulated products within five years if the technical studies indicated that copper in brake pads was contributing significantly to water quality impairment. The State Water Resources Control Board and Caltrans together contributed close to $1 million towards paying for the subsequent research into the issue. In late 2007 the Partnership completed a series of interlinked laboratory, environmental monitoring, and environmental modeling studies that indicated that brake pads are a substantial contributor to copper in runoff to the San Francisco Bay. As the technical studies’ results emerged, the Partnership shifted its focus to determining an appropriate mechanism for reducing copper in brakes in California. The result is SB 346 - the product of a collaborative, consensus-based approach to crafting a workable balance between necessary innovations, long manufacturing timelines, and the stringent water quality compliance deadlines facing California.
    • Q: Why legislation? Why not develop regulations through the Green Chemistry Initiative process instead?
    • A: SB 346 represents a finely-tuned balance between interests usually viewed as in conflict with one another. Both industry and the municipalities faced with TMDL deadlines need certainty and quick action. Rulemaking for the Green Chemistry Initiative has not begun, and it will be at least one to two years before the process begins. Once begun, the process will create a great deal of regulatory uncertainty and consume a great deal of time for industry and others as it unfolds. Any delay in the timeline will make it even more difficult for municipalities to meet their TMDLs, and will put pressure on them to take other, more expensive and less effective actions to address copper in the affected water bodies. Finally, other than a small amount of funding to enable the Department of Toxic Substance Control (DTSC) to go through rulemaking, the Green Chemistry Initiative has not been funded yet. There is no guarantee that DTSC will have the resources to enforce adequately if limits on copper in brake pads were to be put into regulation. SB 346 authorizes the creation and allocation of a fee that will provide funding for its implementation.
    • Q: How safe are brake pads that don’t contain copper?
    • A: Copper-free brake pads of all types are available and in common use. Because zero-copper products are currently used in many vehicles that meet federal vehicle safety standards, it appears that the presence of copper is not necessary for brake pads to function safely, providing that the friction material, in conjunction with the brake system, is suitably engineered for those vehicles.
    • Q: What will the brake manufacturers use instead of copper?
    • A: Brake manufacturers are not sure what they will use to replace copper in brake friction materials but they know there will not be a one for one substitution. Rather, there will be a mix of constituents to provide the performance characteristics that copper provides.
    • Q: Why do we have to wait until 2021 for copper to be reduced to 5%? Why do we have to wait until 2032 for it to be reduced to 0.5%?
    • A: The Partnership has worked hard to balance the need for California to meet federal water quality standards and timelines with the lengthy development, safety and performance testing, and manufacturing timelines for brake pads and vehicles. Brakes containing copper are currently widely used on new vehicles. Eliminating any intentional use of copper in these brakes while meeting the auto companies’ strong performance standards will be revolutionary for the brake industry. Reducing copper to less than 5% by weight in all brakes by 2021 will be a significant improvement in itself, and will allow manufacturers the flexibility they need to achieve the 0.5% standard. Given the amount of work involved, 2032 isn’t that far away, and brake manufacturers will begin product development efforts to reach the 0.5% copper standard immediately.
    • Q: Is copper in brass and other alloys included in the proposed limits?
    • A: Brakes can contain copper in many forms, including copper in alloys such as brass, elemental copper, and copper in compounds. The limits in SB 346 apply to all forms of copper. Brake wear debris is released in very small particles, and our studies indicated that the copper in these particles behaves in and affects the environment the same way, no matter what form it took in the friction material.
    • Q: How will we know that copper isn’t being replaced with something that creates its own set of environmental problems?
    • A: To avoid creating another environmental or health problem, SB 346 prohibits all but de minimis use of cadmium, hexavalent chromium, lead, mercury, and asbestiform fibers in friction materials, all substances known to cause environmental and/or health problems. The legislation also calls for monitoring of nickel, zinc, and antimony, substances that may be used in some brake formulations but at levels that are not currently viewed as a source of environmental or health problems. If the use of nickel, zinc and antimony in friction materials increases by more than 50%, SB 346 requires DTSC to complete scientific studies to determine whether a maximum concentration of any of these materials is needed.
    • Q: What vehicles will be affected by the legislation?
    • A: The following vehicles will be affected:
      • Passenger vehicles
      • Light duty trucks
      • Commercial vehicles
      • Heavy duty on-highway commercial vehicles
      • Heavy duty off-highway vehicles (agricultural tractors, mining vehicles, construction equipment)
      • Motorcycles
      • Golf carts
      • Industrial site vehicles (e.g. forklifts)
      • Off-road vehicles (e.g. ATVs)
      • Racing vehicles
      The following vehicles would not be affected:
      • Airplanes
      • Trains
      • Human powered vehicles (e.g. bicycles)
      • Segways
      Military vehicles, fully sealed non-copper emitting braking systems, and parking brakes would also be exempted.