The results of analysis done with respect to
production year are given in Fig.2. In case of all the
four substances except T-Br, heavy metals in plastic
can be regarded as contamination source included in
the plastic as additional agents and colorant. Pb
contents peaked in the products manufactured in 1998 and Cr contents were peaked in the products of the
year 2002. The contents of T-Br were gradually
increased from 1989 to 2005 on account of using
brominated flame retardants (Fig.3). In contrast, T-Br
contents were remarkably decreased since 2005 by
magnifying implementation of international
environmental regulation regarding RoHS Directive.
Moreover, it is considered that other flame retardants
had been substituted for brominated flame retardants
or they were used less as export to the European Union
had been forbidden since July 2006. As per RoHS
Directive, member states must ensure that from July
2006, newly marketed EEE does not contain above
mentioned six hazardous substances higher than
defined maximum concentration values for
homogenous materials.