This page contains a Flash digital edition of a book.
Such data is available from the National Renewable Energy Laboratory’s U.S. Life-Cycle Inventory database.


LCA Information such as this, comparing the environmental impacts of various types of plastics, shows that choosing one material over another for its green characteristics can be complex and nuanced. Understanding what each of these terms means, and which might be of particular concern, is essential to making an informed choice.


GB: Why are big companies such as Wal-Mart banning PVC, if the product is problem free? (Link here: www.planetizen.com/node/19261). I realize many rigid building materials do not contain phthalates (notably PVC pipes—an error one of our freelancers made recently), but PVC to my understanding has been banned in Germany and the Netherlands, and California is looking at a partial ban on some PVC products.


SS: In response to the comment about banning rigid PVC, we have been unable to find any large-scale bans. There is some information about Germany refusing to use vinyl siding on public buildings, but that is the only instance we are aware of. While flexible PVC may use phthalates, phthalates are not used in vinyl siding, and therefore, do not contribute to any impacts when analyzing vinyl siding.


There are some companies, such as Wal-Mart, which are making an effort to reduce their usage of PVC. This has proven difficult, because, while there are some uses for PVC which has viable replacements, there are other situations in which PVC is the most suitable material.


The argument is not that PVC should be used for everything, but simply that there are uses for which it is an extremely suitable material; and in those instances, efforts to replace it with other, less suitable, materials may result in higher environmental and human health impacts.


GB: Why is recycling of vinyl siding and windows post consumer so low? Something’s not working. The excuse that virgin resin is cheaper than recycled resin is not good enough.


SS: The United States has very low recycling rates for plastics in general.


The recycling rates and total amount of each plastic in the municipal solid waste (MSW) stream are listed in the table below. As you can see, while there is no significant PVC recycling, the contribution of PVC to landfill waste is by far lower than any of the other plastic resins, yet the volume of PVC sold and used in 2009 in the U.S. ranks third among the listed resins (behind PP and HDPE). This is at least in part due to the durable nature of many PVC products.


Durable goods made from PVC, such as siding, pipe and decking, will last for decades and do not appear in the MSW stream in any significant amount. This can be seen in the fact that the NAHB has cited “Lifetime” as the estimated life expectancy of vinyl siding on a home in its “Study of Life Expectancy of Home Components,” published in February 2007. The small potential supply of recycled PVC resin and the lack of a collection and processing network has been a major barrier to the recycling of PVC in the past.


08.2011
23

Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76