Misclassification of Copper in Building Construction: Risks vs. Hazards (Part I)
Joe Gorsuch works with environmental regulations and the collection of ecological toxicity data. For 30 years prior to joining the CDA in 2009, he worked with Kodak, conducting environmental effects and stability studies in the laboratory and outdoors to register chemicals for the photographic industry.
Joe Meyer is a Technical Expert for ARCADIS, an international organization that provides consultancy, design, engineering and management services in the infrastructure, water, environment and building fields. Joe is a former professor in the Department of Zoology and Physiology at the University of Wyoming. While at UW, Joe was involved with U.S. EPA Science Advisory Board activities in both aquatic toxicity and water quality programs.
U.S. architectural firms recently have moved toward designing buildings that are considered “environmentally friendly,” promoting the use of green materials that they hope will have few if any negative effects on the environment.
In their desire to mitigate environmental impacts in building construction, architects are using or recommending what they consider “less harmful” materials in their projects. Building professionals have also followed the lead of state governments, municipalities and non-governmental organizations, which in recent years have unwittingly classified copper as a “chemical of concern,” although it is not included in the official list identified by the U.S. Environmental Protection Agency.
These claims haven’t always been examined or evaluated using scientific data in an appropriate context. And there have been few attempts to define risks vs. hazards in the use of copper as a viable construction material.
Copper is a natural element present in the world around us and has been used by humans for more than 10,000 years. Copper is used for multiple applications – construction, electronics, communications, transportation, energy, advanced technology and in health care. Copper is vital to the health of plants and animals, and is an essential part of the human diet.
Copper and its alloys have historically been valued as building materials because they can be shaped by any of the common fabricating processes. Copper is also durable, corrosion-resistant and recyclable. Many historic buildings have copper elements that have lasted for more than 100 years. Copper is beautiful and has long been valued for its unique patina.
When considering the environmental impact of copper and its use in building construction, architects, developers and contractors have unknowingly moved toward a decision-making process based on hazards, rather than risks. Simply put, hazards are defined as hypothetical worst-case scenarios. Risks are defined as the probability of harm occurring in specific contexts – with analysis on a case-by-case basis.
What does this mean for copper? In determining if copper roof runoff, for example, poses a hazard or a risk to fish that may be in a nearby stream, consider these facts:
- Acids, which can occur naturally in rainwater, will dissolve only a small amount of copper in the roofing material.
- Rates of copper corrosion vary from region to region, depending on the chemistry of the atmosphere.
- By the time the rainwater travels from the roof, through the downspout, gutters and drain pipes, across concrete walks or driveways, through grass and soil and eventually into a stream, the amount of copper that remains in a solution is usually too small to negatively impact living organisms and fish.
What people don’t ask is what comes in contact with the fish in the stream – that’s the context part of it. There won’t be much copper by the time the water reaches the stream and that’s the difference between a potential hazard and an actual risk. Plus, many of the natural chemicals in a stream will decrease the potential effects of copper even further. In Part II of our blog, we take a look at the scientific studies.
In Part II of our blog, we take a look at the scientific studies.
For more information on copper as a building material, please contact email@example.com
Photography courtesy of Ilene Tyler