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- Practical Guide -
Page 96 of 153
In Europe, it is the authorities that decide what is safe for the consumer and what is not. In
most cases the industrial actors of packaging have only to comply with legislation, and do not
have to decide themselves what is safe for the consumer. As we have seen in the
introduction, the responsibility of compliance belongs to the industrial end user of the
material and the most of the relevant knowledge is property of the resin manufacturer.
This work contributes to guidelines for introducing migration into good manufacturing
practice. Full guidelines will be presented in the next paper. The fingerprint based strategy
proposed here, is simple to use and will certainly become very useful. Extension of this work
is likely to show that fingerprints of approved materials can help for the identification of
quality defects.
Materials were classified by industry. They represent all the main structures on the market.
Other materials may behave slightly differently, and it may be wise, if a good accuracy is
required, to determine their actual extraction kinetic parameters (E) values (e.g. for a quality
control scheme). For enforcement, the E values given in the document are probably
sufficient. However in any case, it would be advisable that further research programmes
corroborate the use and the scope of E values.
The selection of extraction solvents and of alternative test media relies on a large scientific
literature. First the possible solvents are deduced from the identity of the polymer. As far as
possible, we tried to recommend several solvents for each polymer. Then, the selection of the
right solvent depends on the potential migrants, and on their solubility in the possible
solvents. These selectivity effects play an important role, even at concentrations well below
the solubility limits.
All the materials studied, in use in different European companies, did comply perfectly with
the EU regulations and directives.