Novara Environmental Statement 2007 English MEMC-NO ...

Analysis of the data shows a generaldownward turn in total consumptionand a constant specifi cconsumption value, demonstratingthe controlled managementof chemical substances, focusedon meeting production needs andpreventing waste. The situationsidentifi ed last year, as describedhere below, remain unchanged:upward trend in absolute andspecifi c consumption of trichlorosilanethat can be attributed to theincreased production of epitaxialwafers, and the increased thicknessof monocrystalline silicondeposited on the epitaxial wafers,requested by clients over the last3 years;Consumption of chemical sustances: Trichlorosylane SiHCl 345Annual consumption (t)3525152000 2001 2002 2003 2004 2005 2006 2007YEAR0,240.160,08Specifi c consumption (t/MSIE)Total annual consumptionSpecifi c consumptiondownward trend in the consumptionof acids (with particularreference to hydrofl uoric acid, asubstance that brings the factorywithin the scope of the ItalianLegislative Decree 334/99 concerningmajor accident hazards)and acid mixtures used during thepost-lapping etching stage, obtainedthanks to the introduction ofan alternative caustic etching processusing potassium and sodiumhydroxide, substances with aconsiderably lower environmentalimpact than those used for acidetching;Consumption of chemical sustances: Nitric acid 65%Annual consumption (t)50403020102000 2001 2002 2003 2004 2005 2006 2007YEARConsumption of chemical sustances: Hydrofluoric acid 49%Annual consumption (t)180160140120100802000 2001 2002 2003 2004 2005 2006 2007YEAR0,210,160,110,060,011,150,950,750,550,35Specifi c consumption (t/MSIE)Specifi c consumption (t/MSIE)20