Polystyrene cladding is usually selected purely on an aesthetic consideration. Certain companies claim that polystyrene is a ‘green’ product due to its insulation qualities but I disagree. Polystyrene cladding sheets are a construction material that can be used in a wide variety of building applications. Polystyrene has insulating properties to reduce energy for heating and cooling. The product is manufactured in different R-value grades offering varying thermal resistant qualities. Pests are not attracted to polystyrene which increases the lifespan of the product if installed correctly. Polystyrene also boasts excellent moisture resistance. Effects of short-term levels of exposure to benzene have been known to cause dizziness, headaches, vomiting, convulsions, coma and death from irregular heartbeat. Long term effects have been known to cause skin scaling, leukemia, plastic anemia and death (Kremer, 2003). Exposure to styrene can cause eye, nose and throat irritation, dizziness, brain damage, loss of consciousness, fetal damage, lung cancer, decreased fertility and trouble balancing (Kremer, 2003). Styrene, included in the product has been classed as reasonably anticipated to be a human carcinogen in the 12th Report on Carcinogens in the National Toxicology Program (NTP) (Building Green, n.d).
Polystyrene is a non-conductive material. In contrast to conductive materials, non-conductive materials impede the free flow of electrons from atom to atom and molecule to molecule (Physics Classroom, 2014).
It is usual for manufacturers to add flame retardant to the polystyrene, making it virtually self-extinguishing (Downton, 2013), this adds to the toxicity of the product. A concrete render – cage – occurs when concrete and steel buildings screen out natural radiations which help regulate life systems.
It’s important to add here, that there are no standards on how to correctly build with polystyrene and it is my belief, that until standards are put in place, and the safety of this material is PROVEN, the use of polystyrene in our buildings should be avoided.
FUN FACTS ABOUT POLYSTYRENE
Embodied Energy – 88.60 mj/kg
Raw Material Extraction – All plastics are derived from crude oil which is a non-renewable fossil fuel. The burning of fossil fuels to make plastic products releases carbon dioxide which is a greenhouse gas. Air and water pollution is also generated from the energy-intensive process of fossil fuel extraction (California Energy Commission, 2012).
Benzene – Is a clear, colourless liquid with a noted pleasant odour extracted from coal and also found in gasoline (Kremer, 2003). The extraction of coal has a large negative impact on the natural environment causing plant life to die and leading to erosion. Working coal mines is also hazardous. Styrene Monomer is a clear, oily liquid with a slight odour and is extracted from petroleum. Ethylene is a colourless gas that becomes a liquid at low temperatures and is used as one of the two new blowing agents in the production of polystyrene.
Processing – Blowing agents – Ethylene and HCFC’s. To make polystyrene certain gases are injected into the plastic making tiny holes that become gas and air filled pockets when the plastic cools. Tiny grains of styrene are expanded using steam. The expanded beads are then moulded into shapes or large blocks depend on the application (EPSA, 2014).
Manufacture – Benzene and styrene are listed on the hazardous substance list because they are a known mutagen, carcinogen and are flammable. Styrene is also considered a neurotoxin.
Transport – Based on polystyrene products being available in most states of Australia I am basing transport on the pollution rates from freight trucks. Due to the demand of the product there is a large amount of exhaust pollution, oil-to groundwater seepage pollution, and break pad dust that escapes into our environment (Styrofoam). Polystyrene products are light weight which reduces consumption of transportation fuels (Foamex, 2012).
Usage – Polystyrene cladding sheets are a construction material that can be used in a wide variety of building applications. Polystyrene has insulating properties to reduce energy for heating and cooling. The product is manufactured in different R-value grades offering varying thermal resistant qualities. Pests are not attracted to polystyrene which increases the lifespan of the product if installed correctly. Polystyrene also boasts excellent moisture resistance. Banked emissions result when a portion of a blowing agent sealed in the closed cell structure of the boardstock slowly diffuses out of the foam over a long period of time. Maintenance depends on use of the product and what it is sealed with etc. Based on my research, the low maintenance properties of the material and insulation values do not outweigh the negative impacts on the environment.
Toxicity – The ingestion of polystyrene fragments kills wildlife. Effects of short-term levels of exposure to benzene have been known to cause dizziness, headaches, vomiting, convulsions, coma and death from irregular heartbeat. Long term effects have been known to cause skin scaling, leukemia, plastic anaemia and death (Kremer, 2003). Exposure to styrene can cause eye, nose and throat irritation, dizziness, brain damage, loss of consciousness, fetal damage, lung cancer, decreased fertility and trouble balancing (Kremer, 2003). Styrene, included in the product has been classed as reasonably anticipated to be a human carcinogen in the 12th Report on Carcinogens in the National Toxicology Program (NTP) (Building Green, 2014).
Demolition – Polystyrene building products are lightweight and easy to handle reducing energy needs for machinery in demolition saving emissions from fuel. During demolition because polystyrene is so light, pieces break off fly away and have a very negative effect on the environment.
Recycling – Companies who claim to recycle polystyrene in NSW outline the following (ESPA, 2014):
* During production, all manufacturing waste can be fully reprocessed back into the production mix for the manufacture of new EPS products.
* EPS offcuts from building applications can be recovered and recycled during the construction process.
* The EPS is recycled through granulation and is then stored in a hopper before being compacted.
* The compacted EPS is then melted, pelletised and converted into Green Purpose Polystyrene (GPPS).
* Products made using recycled EPS include CD and video cassette cases, coat hangers and synthetic timbers.
Unfortunately, in my opinion, polystyrene building products are a case of green washing, claiming to be environmentally friendly despite the fact that the product is not an unadulterated, natural building material, is not capable of sorption, has toxic vapours, the production wastes energy and is hard to recycle. After phone calls to recycling companies surrounding my local area and a large recycling company referred by others who take their bins to them, Visy, I found that polystyrene is not actually recycled but instead put into landfill with other non-recyclable building materials. A phone call to a company who specialise in polystyrene recycling, CBC, found that if polystyrene is rendered and has concrete attached, it is highly unlikely that it can be recycled, or it would cost a lot extra to recycle than clean material. On further discussion with this company, I was informed that no companies in Australia actually recycle polystyrene onsite, instead it is sent overseas where it costs less than 50% to recycle the material into products mentioned above. Therefore in regards to a life cycle analysis and the energy used to ship polystyrene overseas and then back to us in recycled products, I would not recommend polystyrene as a building material.
Disposal – Polystyrene is bulky and non-degradable which means it takes up a significant volume of landfill. Burning polystyrene gives off over 90 different hazardous chemicals, including styrene vapours and dioxins. (Kremer, 2003). It captures water in landfills and soaks into garbage which stops other landfill it from breaking down normally. Emissions from transport to landfill and landfilling machinery.
To polystyrene or not to polystyrene – the evidence is clear! Do you want to know more about building materials? Contact Building Biology NSW today.