What is migration?
FAQ
What is migration?
Migration
= Transfer of substances from the packaging
to the packed food product.
The concentration of migrants is stated in mg/6dm2 of packaging or mg/kg
(ppb) of foodstuff packed.These traces may not always be detected in
organoleptic testing (odour and taste tests) or when consumed but may be
found by sensitive chemical analysis.
Potential migrants are e.g.:
 Plasticizers from plastics or inks
 Monomers from plastics or coatings
 Solvents, washes & cleaning chemicals, oils and greases
 Low molecular weight components from substrates or adhesives etc.
 Low molecular ink additives (e.g. photoinitiators)
 Hydrocarbon distillates or mineral oils from conventional inks
Main methods of migration
Set-off migration
Ink
Food contact
surface
Substrate
Food
Through migration
 Through migration = Migration from the printed side through the
substrate onto the unprinted side.
 Set-off migration = Migration from the printed side to the unprinted
side of another sheet in a stack or roll
Migration - FAQ
 What is migration?
It is the transfer of substances from the packaging to the packed food
product. These traces may not always be detected in organoleptic
testing (odour and taste tests) or when consumed but may be found by
sensitive chemical analysis.
 How does migration occur?
Migration can occur by three different mechanisms:
- Penetration through the substrate
- “Set off” transfer onto the reverse side in the stack
- Vapour phase transfer (only in case of metal decoration)
Migration – FAQ
 How do you measure migration and in what units?
– Migration is measured by accredited laboratories using sophisticated
measuring cells and highly sensitive chromatography or mass spectroscopy
equipment.
– Measuring migration from printed packaging is a much more complex task
than assessing impact on odour or taint.
– Migration is measured by determining the identify of, and amount of,
materials that transfer from the packaging material sample ideally into a
control sample of the actual food itself.
– In practice, analysis of food samples is difficult and so food simulants are
used to mimic the nature of the food itself.
Different models are possible (area of print, weight of food simulant, contact
time and temperature) and the results are often quoted in parts per billion
(ppb); actually micro grams per kg of food.
The migration models for different food stuffs are set out in EC regulation and
are normally quoted from migration tests using the following model:
600 cm2 of print, 1kg of food, 10 days at 40°C.
Note: these are subject to periodic review and updating.
Migration – FAQ
North American legislation
• FDA regulates the materials which can be used in items (packaging) which
will come into contact with food.
• The base assumption is that any materials used in food contact applications
will become part of the food unless documented testing proves otherwise.
• The FDA provides a list of approved materials in title 21 CFR (Code of Food
regulations).
• Inks and coatings that do not have direct food contact are not regulated, as
long as there is a “functional barrier” between food contact side and the ink
or coating, and the inks and coatings do not migrate to the food contact side
during various steps in the process.
• It is the responsibility of the packaging manufacturer to determine if the
construction meets the definition of a functional barrier.
Migration – FAQ
 What level of migration is acceptable?
The determination of an “acceptable” maximum level of migration is based on the
toxicological profile of the migrant material and in some cases the availability and expert
assessment of the toxicological data. In all cases of migration the migrates must be
identified in order to carry out a risk assessment. The below data are used in Europe and
agreed among leading end users and food safety organisations.
Measured level
Description
Note
<10 ppb
No effect level
#1
10-50 ppb
Evaluate test result
#2
> 50 ppb
Full evaluation
needed
#3
Note: migration testing can take some weeks to complete due to sample
preparation times before and after the period in the migration cell
Note 1:
Even if the level of migration is less
than 10ppb (the no concern level )
there must be no material detectable
with potential carcinogenic activity.
Note 2 :
There are 3 mutagenicity tests (Ames
and 2 in vitro tests) and all must be
negative ( i.e. absence of genotoxicity )
Note 3:
The full toxicological profile must be
evaluated by a competent expert and
approved at this level of migration. For
example, one of the migrants may be
an approved food additive. Ultimately a
dossier should be submitted to EFSA
for development of TDI / SML.
Migration – FAQ
 Is migration time dependant?
Yes, migration is a time dependant phenomenon, basically the longer potentially
“migratable” components are in the proximity of the packaged goods the greater the risk of
migration although there will ultimately be a dynamic equilibrium established between the
migrant level in the food and in the packaging.
 What migrates?
The following is a non-exhaustive list of typical potential migrates:
–
–
–
–
–
–
Plasticizers from plastics or inks
Monomers from plastics or coatings
Solvents, washes & cleaning chemicals, oils and greases
Low molecular weight components from substrates or adhesives etc.
Low molecular ink additives (e.g. photo initiators)
Hydrocarbon distillates or mineral oils from conventional inks
 Why measure migration?
To be sure that packaging complies with regulations. Measurements undertaken by an
accredited laboratory of fully commercial and representative production packaging may be
required.
Depending on the result of a risk assessment from package design to the filling line,
migration testing at an appropriate frequency may form part of the necessary production
protocol and specification. A first stop may be the establishment of a relationship (mutual
understanding of requirements) with a local or regional competent, accredited laboratory.
Migration – FAQ
 What are “low migration” products?
Low migration products for use in low migration printing are consumables specifically
formulated and tested for this application. Essentially they are made from materials that
under normal or foreseeable conditions of use do not migrate – when correctly applied in the
intended application – at a level which would prevent migratables from the finished package
being above the currently accepted limits.
 Does Flint Group offer Low Migration(LM) Inks for all applications?
Flint Group Narrow Web offers Low Migration inks in UV Flexo – Flexocure
ANCORA
We can offer Low migration technology for many other print applications (
sheetfed offset, flexo & gravure SB)
 Can Flint Group ensure that once printed with Flint Group inks there won’t be
any migration?
No. The responsibility for the compliance of the packaging does not lie with one individual
member of the packaging chain. A co-operation between all partners along the packaging
chain is important to reduce the overall risk of migration and Flint Group plays an active
role to assist in this matter.
Summary
 The responsibility for the compliance of the packaging does not lie
with only one individual member of the packaging chain.
 There shall be no unacceptable change in the quality, odour or taste of
the foodstuff
 There shall be no use or migration of carcinogenic, mutagenic or
reprotoxic substances (CMR substances)
 The migration of substances evaluated for food contact shall remain
below defined limits (according to SML or < 10ppb)
 There shall be no adulteration of the foodstuff.
 Packaging Inks for food packaging are not covered by any specific
legislation.
 Ultimate responsibility is with “person placing pack on market” – but
we all have to work together.