1. An industry association founded in 1954. The members include ten PVC pipes and fittings manufacturers and four related industry associations. Recycling of PVC pipes has been a major activity of the association. http://www.ppfa.gr.jp/ . Accessed 14 Feb 2015
2. PPFA guidelines for purchasable waste pipes and fittings http://www.ppfa.gr.jp/recycle/purchase/standard.html . Accessed 14 Feb 2015
3. Some partner companies and contracted intermediate treatment companies produces pellets as well. However, PPFA does not buy pellets as they are compounds with additives for specific applications
4. Eligibility of application for contracted intermediate treatment companies set by PPFA. http://www.ppfa.gr.jp/recycle/bosyu/
5. PPFA Partner Companies http://www.ppfa.gr.jp/recycle/purchase/list.html . Accessed 14 Feb 2015