CURRENT MIGRATION LIMITS (Europe)
The current regulations state that migration levels for:-
Individual substances that do not meet 3 mutagenicity tests must be below 10 parts per billion.
Individual substances that do meet 3 mutagenicity tests must be below 50 parts per billion.
It is the responsibility of the packaging converter (printer) to ensure that the printed packaging meets the current regulations pertaining to the printing of the non-food contact surface of the food package/label.
When printing the non-contact surface of a food package, Low Migration inks are only required if there is no effective barrier to migration between the print and the food.
Substrates or containers made of steel, glass, and aluminium foil are effective barriers to migration. However in some cases where the substrate is an effective migration barrier, for instance an aluminium foil lid for a yogurt pot, there is still a risk of migration from ink set-off/migration in the printed stack or reel. In this instance the set-off/migration is in direct contact with the food. Other packaging materials such as plastic bottles, plastic films, metallised foil, multi-layer plastics etc. will impart varying degrees of migration protection. Check with the substrate supplier.
Migration analysis should be performed by an approved Analytical Institute.
The type of test will depend on the type of foodstuff, and package.
The ink manufacturer will, under a Non-Disclosure Agreement, provide the Analytical Institute with a full breakdown of the ink formulations used to print the package/label.
The reference codes of the inks used on the packaging to be tested should be conveyed to the Analytical Institute and/or the Ink Manufacturer so that the correct formulation breakdowns can be provided.
The ink manufacturer will comply with the EuPIA Guidelines concerning the best practice for the manufacture of inks for the Non-Food contact surface of food packaging materials and articles.
All raw materials used in the printing inks will be listed on the EuPIA inventory list – version January 2011 - comprising of packaging ink raw materials applied to the non-food contact surface of food packaging.
PACKAGING CONVERTER (PRINTER)
It is the responsibility of the Packaging Converter (Printer) to ensure that all other materials used to produce the package or label are fit for purpose. This should include materials used to clean the printing machine. All parts of the press that are likely to contaminate the package or label must be thoroughly cleaned before printing commences. If Non-Low Migration or Non-Food Grade inks have been used prior to the Low Migration print run, all inking rollers and blankets must be thoroughly washed and dried beforehand.
If migration levels are to be as low as possible it is essential that the print is cured as well as possible. There are many factors that influence the degree of cure. It may be possible to cure certain ink formulations to a level that meets migration limits if sufficient UV lamp power is available at a relatively slow press speed. Printing conditions and inks used on work that gains low migration certification must be strictly controlled for subsequent print runs. In the first instance it is best to try to gain certification with a worst case scenario, i.e. heavy ink coverage, minimum available lamps, highest press speed, etc. UV lamps must be checked regularly to ensure they are performing correctly.
CLASSIC COLOURS UV PROCESS INKS
It can be the case that our standard Nevada Classicure LA Yellow (PY8973) Magenta (PR8974) and Cyan (PB8975) will meet current migration requirements, if printed on a semi rotary label press at 40mpm. These inks are a lower cost option, and only the black will need changing. However their use must be verified by an approved Analytical Institute that have been provided with formulation breakdowns for these inks. Our Nevada Classicure LA LM process colours (Low Migration Formulation) Yellow (PY9590) Magenta (PR9591) Cyan (PB9592) and Black (PN9593) have optimum photoinitiator levels to ensure the best cure quality under a wide range of printing conditions.
We do not propose at this time to offer Low Migration formulations for PS, 74G, or PC inks. Nevada and Sahara PC colours have good low migration potential, but there is no special toned black available.
PIGMENTS NOT PERMITTED
There are several pigments used generally in printing inks that are not permitted for use on the non-food contact surface of food packaging. These are:
Pigment red 81 Pantone Rhodamine Use Nevada PC LF+Resist Rhodamine MS9387
Pigment violet 2 Pantone Purple Use Nevada PC LF+Resist Purple MS9388
Pigment violet 3 Pantone Violet Use Nevada PC LF+Resist Violet MS9389
Pigment blue 61 Pantone Reflex Blue Use Nevada PC LF+Resist Reflex Blue MS9391
Pigment blue 1 Pantone 072 Blue Use Nevada PC LF+Resist 072 Blue MS9392
There are substitute pigments available for all these pigment types but in most cases strength and brightness will be compromised. The plus side is that they are all more lightfast, heat resistant, and resistant to solvent and chemical attack.
LOW MIGRATION BLACK INKS
Most black inks are toned with Reflex Blue. As this pigment is not allowed in low migration food packaging inks it is necessary to replace it with a combination of other pigments. This change results in a slight loss of density.
CLASSIC COLOURS BASIC COLOURS
All our Basic colours in the Nevada Classicure LA and PC ranges have Low Migration potential as far as photoinitiator level is concerned. Basic colours that contain pigments listed above (Not Permitted) and Nevada Classicure PC Basic Black should be avoided. Currently the permitted versions of these colours (LF + Resist) are only available in the Nevada Classicure PC range. These PC versions should print well on Semi Rotary label presses but may not be suitable for foil stamping.
TRANSPARENT WHITE AND PALE TINT COLOURS
An updated version of Nevada Classicure Transparent White MS7410 has been formulated for low migration work. We have introduced a new photoinitiator that improves cure speed whilst retaining the non-yellowing property and resistance to ambient UV light sources. This faster curing version ensures that any blends made with the Basic colours have maximum cure speed and the lowest possible migration properties.
We intend to label only inks that have the best “Low Migration Potential”. The words LOW MIGRATION FORMULATION will appear beneath the main description. Although we will endeavour to provide inks that offer the lowest migration properties, it is the responsibility of the packaging converter to ensure that printed work produced with them, meets the current migration regulations.
The information given above is to the best of the company’s knowledge and belief, accurate and reliable as of the date indicated. However, no warranty, guarantee or representation is made to its accuracy, reliability or completeness. It is the user’s responsibility to satisfy themselves as to the suitability of such information for their own particular use.