title: Environmental impact assessment of chlorine in liquid crystal display glass (LCDG) based on material flow analysis.
abstract: Liquid crystal display glass (LCDG) may contain chlorine in trace amounts to attain some of its special properties. LCDG is primarily manufactured by glass companies, which then supply the electronic industry for utilization in the manufacture of items such as televisions, computer monitors, etc. In order to be seen as environmentally friendly, some electronic companies that utilize LCDG request that glass companies eliminate halogens such as chlorine from LCDG. The issue of halogens in products is often associated with dioxin-like problems. By using halogen-free LCDG in their manufacturing process, electronic companies aim to enhance their eco-friendly branding. Nevertheless, the real gains in terms of environmental improvement are yet to be assessed. In this study, we discussed the effectiveness of reducing or eliminating chlorine in electrical and electronic products on a scientific basis, by carrying out a quantitative assessment of cancer risk posed by potential emissions of dioxins when discarded LCDG is incinerated. The results indicate that the maximum increase of individual lifetime cancer risk is 3.2 × 10(-10). This level of cancer risk is negligible. Consequently, we suggest that there is no need to introduce stricter standards for chlorine content in LCDG, from the viewpoint of potential dioxin formation.
authors.affiliation: Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya, Yokohama 240-8501, Japan. kotani-kensuke-sc@ynu.ac.jp
authors.forename: Kensuke
authors.initials: K
authors.lastname: Kotani
authors.forename: Shigeki
authors.initials: S
authors.lastname: Masunaga
mesh_terms: D002713:Chlorine / Q000737:chemistry*; D004147:Dioxins / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods*; D017745:Incineration; D050866:Liquid Crystals / Q000737:chemistry*
chemical_list: D004147:Dioxins; D002713:Chlorine