TDK Corporation certified TDK Recording Media Europe S.A. in September 2001 as the first member company of the TDK group to meet the strict TDK zero emissions standards. TDK Recording Media Europe, the first site to be certified, now recovers, purifies, and reuses cleaning solvent (diacetone alcohol) that in the past was discarded without processing and has started reusing the polycarbonate used in the substrates of CD-R and other discs. Among the reasons for the certification was the suspension of atmospheric release of tetrafluoropropane (TFP) and construction of an original recovery system to recover TFP as calcium fluoride for reuse as a basic material for cement.