The hidden pollutant in our brake pads

People don’t think too much about their brake pads until they need to stop their car but, there is more going on under the bonnet than you may think.

Metallic brake pads are commonplace throughout the world.  Here in New Zealand most of the brake pads fitted to our vehicles contain copper and other heavy metals like mercury, lead, cadmium and chromium.

Copper is used in our brake pads because it makes for a smooth braking experience and also has properties that help prevent brakes from squeaking and shuddering when used.

The effects of copper in our waterways

What many people don’t know is that copper, leached from brake pads, can have lethal impacts on urban water quality and aquatic life.

When we use the brakes on our car, fine particles of copper and other metals within the pads flake off and are deposited on our roadways.  When it rains, these particles are then washed into the gutters and through the stormwater system where they flow into our rivers and lakes.  

This is the most common source of metal pollutants in our waterways.  Other sources of metals in our waterways include zinc from vehicle tyre wear and runoff from galvanized iron roofs.  

Because metals do not break down, all metals released in stormwater discharges will end up somewhere in the environment and they will be there forever.

Copper and zinc are essential trace elements for animals (including humans), plants and micro-organisms.  However, at higher concentrations, both copper and zinc have toxic effects that can be lethal (resulting in death) or sub-lethal (slowing growth, reducing reproductive success or leading to abnormal development).

In 2010, both the states of Washington and California passed legislation requiring brake pads sold or installed to have reduced levels of copper and other heavy metals.  Here in New Zealand, there is little awareness about the issue.  Many motorists do not know the damage that is being caused by the brake pads they use, or that they have a choice when selecting brake pads for installation in their vehicle.

What you can do to help

Low copper and copper free friction materials used in brake pads can now outperform other friction materials and they do not compromise vehicle safety or performance.  The cost of installing copper free or reduced copper brake pads is only about $10 -$15 more expensive than traditional pads and they are easily available.

So, next time you are changing the brake pads on your vehicle ask for a quote for a copper-free option. It could make a world of difference.