HOW GREEN IS POLYSTYRENE?
While it’s true that Expanded Polystyrene (EPS) is a non-biodegradable, petroleum derivative, this readily available material, has an important and appropriate role to play in the green building industry.
The critical issue is more about how EPS is used.
Its role as ubiquitous disposable fast food container, on the way to spending 1,000 years in landfills, has understandably given Expanded Polystyrene a bad reputation. As a result, many are eager to condemn it as “bad for the environment”. However, there is a significant moral difference between using it as a disposable item and using it to keep building and home occupants healthy and comfortable, at reduced initial and long-term costs, for the entire life of structures.
According to The Department of Energy (DOE), “EPS can help meet green building goals through its use in innovative applications that improve the overall environ-mental performance of the building envelope”. Furthermore, “EPS is the most cost effective insulation material (R-value/$) on the market today. Good insulation is one of the best ways to reduce our dependence on fossil fuels and reduce CO2 emissions, or global warming potential”.
Facts About EPS and the Environment
- EPS is 96 % air (depending on density). Only 4% is material, which makes EPS a uniquely resource-efficient material with a small carbon footprint.
- EPS is relatively lightweight for its strength, which reduces fuel consumption when transported to, and installed at job sites, compared to heavier building materials. This saves resources of energy expended in transportation and running of heavy equipment – generally not needed.
- Recyclability – Polystyrene is a thermoplastic, which allows it to be continuously melted and reformed, making EPS a highly recyclable product Thousands of tons of EPS are recycled every year. As a single, inert polymer, it is straightforward to recycle into items such as hardwood composite decking, garden furniture, toys or disposable cameras, etc.
- EPS is HFC, CFC & HCFC free. EPS is defined by the environmental “sustainability movement” as a “green building product”. The most significant potential emissions to the atmosphere from expandable polystyrene manufacturing and molding operations is pentane, the blowing agent. Pentane is a paraffin hydrocarbon and has a Global Warming Potential (GWP) of zero. It is not registered as a substance hazardous to human health or to the environment by the U. S. Department of Labor for Occupational Safety and Health Administration (OSHA), nor does it adversely affect indoor air quality. (DOE)
- Styrene, used in the manufacture of EPS, occurs naturally in many commonplace products including strawberries, beans, nuts, beer, wine, coffee and cinnamon.
- In combustion, the amount of carbon monoxide and particulates given off by EPS is a fraction of what is emitted by wood, PVC, paper products or even cotton and wool. Fumes are non-toxic.
- Conserves resources & reduces construction waste stream to landfills. Panel fabrication using computer-aided drafting technology ensures the correct amount of material is used to manufacture Kwik-Build Panels. Job site waste from cutting materials to size at job sites, is eliminated.
- Low pollution process. The manufacture of EPS itself, as well as the fabrication of Kwik-Build Panels, are both low pollution processes. Steam is the key by-product, and water is reused. There is no waste in the process.
From Franklin Associates, Ltd., U.S. DOE and U.S. Census Bureau –
Beyond the environmental benefits of the installed product, the energy requirements to make polystyrene can be more favorable than many alternative materials. In one study, when compared to fiberglass insulation, the energy required to produce EPS insulation was 24 percent less than what is needed to make the amount of fiberglass needed to achieve an equivalent R-value at a representative volume. (DOE)
- While all insulation is inherently ‘green’ due to its energy savings capabilities, green attributes differ, based on each material’s physical properties and its subsequent long-term ability to enhance sustainability.
- More significantly, as part of a highly engineered building system, EPS’ insulating capabilities contribute to increased energy efficiency and plays a key role in a building’s ability to comply with ASHRAE Standard 90.1-2004, a benchmark requirement for most energy saving green building programs.
- In a one-year study, plastic building materials saved 467.2 trillion BTU’s of energy over alternative construction materials.
Closed cell EPS delivers R-values ranging from 3.60 to 4.20 per inch. It is the only rigid foam insulation that offers stable thermal resistance (R-Value) from the point of manufacture throughout the life of a structure. It can provide 2-3 times greater insulation than traditional insulating materials of the same thickness, which typically deteriorate from the time they are installed.
Other rigid foam insulation materials require testing to determine their Long-Term Thermal Resistance (LTTR). This can add to product development costs and render a calculated ‘guess’ at an insulation’s real performance over time. EPS does not have to conduct such tests because it is not subject to ‘thermal drift’, meaning its R-value remains constant throughout the life of the building.
Source: Franklin Associates, Ltd., U.S. DOE and U.S. Census Bureau
Information provided by Kwik-Build Panels, San Diego California.