Migration into food – polythene packaging

With a growing understanding of the effect of different compounds on the human body the migration of chemicals into food from food packaging are the subject of serious public concern.

Context

An increasing amount of food is sold pre-packaged, however this only the tip of the iceberg when it comes to Food Contact Materials (FCMs). Throughout the supply chain raw ingredients, part processed foods and finished products come in contact with packaging, containers and preparation surfaces. These FCMs, wherever they are used, must contain and protect the product from contamination and deterioration, but above all they must be safe.

Legal background

The European Regulation (EC) No 1935/2004 provides a harmonised legal framework for FCMs. It defines the general principles of safety and inertness for all FCMs including packaging. Specifically these principles require that FCMs do not:

  • Release their constituents into food at levels harmful to human health.
  • Change food composition, taste and odour of the food in an unacceptable way.

Moreover, the regulation puts into place additional powers to enable regulations for specific FCMs (e.g. plastics, ceramics, etc.).

Plastics

The most comprehensive specific measure is Regulation (EU) No 10/2011 on plastic materials and articles. It defines rules on the composition of FCMs, and establishes a list of permitted substances for use in their manufacture. The Regulation also specifies restrictions on the use of these substances and sets out rules to determine the compliance of the FCM.

England enacts these European regulations by way of, The Materials and Articles in Contact with Food (England) Regulations 2012. Scotland, Wales and Northern Ireland enact them through similar national regulations.

Approved ingredients

The European Union operates on the principle that products are potentially harmful until proven safe. To this end Table 1 in Annex 1 of Regulation (EU) No 10/2011 contains the list of approved substances suitable for the production of plastic FCMs.

Thus Hanmere only manufactures its films from materials contained in this list.

Overall migration

Included in the regulations are Overall Migration Limits (OMLs) for the migration of substances from the FCM.

The OMLs do not reference any information on the specific substances involved, as their name suggest they only determine a limit for overall amount of all substances that can migrate from the FCM into a simulant.

Specific migration limits

Some substances that are allowed in FCMs have been assigned Specific Migration Limit (SML) values (Column 8 and 9, Table 1 in Annex 1 of Regulation (EU) No 10/2011). If substances with an SML value are used, then a specific migration test must be performed.

A specific migration test may not need to be carried out in either because of a sufficiently low OML, or as a result of cautious estimation of the specific migration.

Typical food simulants

The FCM application determines the selection of the food simulants. The current simulants are:

  • A: Ethanol 10 % (v/v)
  • B: Acetic acid 3 % (w/v)
  • C: Ethanol 20 % (v/v)
  • D1: Ethanol 50 % (v/v)
  • D2: Vegetable oil
  • E: poly(2,6-diphenyl-p-phenylene oxide)

The simulants mimic the contact foods in the following manner:

  • A, B and C mimic foods that have a strong affinity to water and are able to extract similar substances.
  • B mimic those foods which are acidic.
  • C mimic alcoholic foods with an alcohol content of up to 20 % and those foods which contain a relevant amount of organic ingredients that give the food a strong affinity to fat and are able to extract similar substances.
  • D1 and D2 mimic foods that have a strong affinity to fat and can extract similar substances.
  • D1 mimic for alcoholic foods with an alcohol content of above 20 % and for oil in water emulsions.
  • D2 mimic for foods which contain free fats at the surface.
  • E mimic for testing specific migration into dry foods.

In order to cover as broad a spectrum of foods a possible Hanmere commissions OML tests for its films using simulants A, B D2 and E.

Standardised Test Conditions

The FCM application also determines the duration and temperature of the tests, therefore Hanmere tests using the standardised test regimen that most reflects the applications of its films namely OM2.

The OM2 conditions require testing the film in contact with the simulants for 10 days at 40oC. This regimen reflects applications covering any long term storage at room temperature or below. In addition it covers packaging the product under hot-fill conditions at temperature T for no-longer than the period of time t. (70oC ≤ T ≤ 100oC ,  t = 120/2^((T-70)/10) minutes).

Overall migration limit test results

The regulations require that documentation confirming compliance with the OMLs is available. Thus Hanmere includes a summary of its test results in all of its product specifications.

In addition, the full results can be downloaded from the resources page on Hanmere’s website.

Sources:

http://ec.europa.eu/food/safety/chemical_safety/food_contact_materials/legislation_en

http://www.legislation.gov.uk/uksi/2012/2619/contents/made

http://www.hanmere.co.uk/resources/#test-reports

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