A04006: Study of packaging materials used for dietary staples

Study Duration: July 1999 to March 2001

Contractor: Pira International

Staple items of the diet (dietary staples) are packaged in a wide variety of materials and formats. All dietary staples can be purchased in a pre-packaged format, although some may also be purchased loose or packed in-store. They are also distributed, sold and stored under a wide range of environmental conditions. It is these packaging and environmental factors, in conjunction with the nature of the foodstuff itself, which determine the potential for chemical migration to occur.

For those dietary staples that are packaged, knowledge of the materials used for these items in conjunction with an assessment of consumption of these foodstuffs, provides a means of assessing the potential exposure to chemicals that may migrate into the dietary staples from the packaging materials.

Some surveys have been reported which have identified and quantified specific migration risks for individual product / pack combinations. In contrast, this study is deliberately 'broad brushed' in its approach, seeking to provide an overview of potential food migration issues that may exist for packaged dietary staples in the UK. This is achieved by combining consumption data with market information about the packaging materials and formats used for over 100 dietary staples, and evaluating this in the light of existing scientific knowledge of the known and expected migration issues associated with the packaging materials / formats identified. In making this evaluation, environmental conditions influencing the potential for chemical migration are considered, as is the potential presence of post-consumer recycled materials used in plastic and paper based packaging materials.

From the data and evaluation, general conclusions can be drawn on the use of packaging for dietary staples in the UK, and specific instances of chemical migration interest can be highlighted.

The study applied a series of progressive steps to collate and analyse existing data and information on a number of levels of detail.

• First step, existing National Food Survey data was used to quantify and rank consumption of dietary staples in the UK. Consumption data for 1998 was used for the baseline analysis and data for the period 1995-2000 was used to identify any important trends in consumption.
• Then, for each dietary staple the market share by brand and by packaging material / format was determined. Brand shares were determined predominantly from available market research such as Mintel Food and Drink reports. Shares of packaging materials / formats for prepackaged products was determined predominantly through shelf-audits at supermarkets. Some dietary staples, such as fruit and vegetables, bread, and meat and meat products, may also be purchased loose or can be packaged in-store. Where appropriate, the proportion of prepackaged to loose/in-store packing was estimated on the basis of available data on sales distribution channels.
• Factors which may affect migration were determined for each dietary staple / packaging material / packaging format combination. In particular, the analysis considered shelf-life, storage temperature, and the potential for recycled plastic or paper and board to be included in the structure of the primary pack.
• Potential migration issues were then identified. These were drawn from Pira International's existing knowledge and expertise of food migration issues, supported by a comprehensive literature search.
• The market and technical data were evaluated to identify issues of potential migration interest. This was a qualitative evaluation, and was not based upon a toxicological risk assessment.
• A pareto type analysis (the principle that the majority of problems (80%) are produced by a few key factors (20%)) was applied to select specific dietary staples for further consideration and clarification of the extent of potential migration issues. The dietary staples selected by the pareto analysis were subsequently grouped according to common packaging format/components which may give rise for concerns.
• Finally, additional market information and consumption trends over time were presented in order to clarify the nature and possible extent of specific issues of migration interest.

This project identified market shares by brand for over 100 dietary staples in the UK. For each of the dietary staples, the research identified the range of possible packaging materials and packaging formats that are used. The research provided an estimate of the market share of each packaging material/ format by dietary staple. For groups of dietary staples which may also be purchased loose or packed in-store, the research also provides an estimate of the proportion of pre-packaged to loose / packed in-store product.

For the pre-packaged dietary staples, the research identified factors, which may influence chemical migration, such as environmental conditions of distribution, storage, and use, and the potential presence of recycled material in plastic and paper based packaging. Ultimately, from the evaluation of this data, a number of general conclusions have been drawn on the packaging of dietary staples in the UK and the potential migration issues that this may present, whilst specific product/pack material/ pack format combinations with high migration interest have been highlighted.

Conclusions of the research:

• The majority of dietary staples purchased through retail outlets in the UK are contained in primary packaging. For some dietary staples such as bread, fruits and vegetables the proportion of pre-packed product is less significant. However, the use of primary packaging in even these dietary staples is increasing as producers seek to add value and product differentiation.
• Branded products are prevalent amongst UK dietary staples. Branding of fresh produce is less prevalent but is gaining strength in some areas as produce sectors seek opportunities to add value and product differentiation.
• Own branding represents a significant proportion of branded products for many dietary staples. In some cases own brand dominates.
• Within each dietary staple many different packaging materials and formats can be used. For each dietary staple, each brand owner will often use a number of packaging materials and formats.

Considerable efforts have been made by the packaging and food industries to reduce the migration hazards associated with packaging materials. However, despite this a number of issues of potential migration interest have been identified. These are:

• Selected canned foods:- Fish in oil and some vegetable products, meat pies and sponge puddings cooked in the can.
• PVC cling films:- Meats, dairy products and processed foods.
• Flexible PET/PE and PA/PE laminates:- For a wide range of product categories.
• PVC/PE rigid/semi-rigid laminates:- Cheeses, fresh pasta, cold meats and other products.
• Boil in bag, cook in pack (oven or microwave) polymeric or paperboard:- Ready meals and convenience foods.
• Recycled board sandwiched between virgin materials:- For a wide range of products.
• PVC jar and bottle seal:- Baby foods.
• HDPE bottles with printed PVC shrink sleeves:- Yoghurt and milk drinks.
• EPS trays:- For high fat mince & pork with the fat on etc.
• Oxygen scavengers:- For a wide range of products.

Final report is available from the FSA Library and Information centre. To obtain a copy, please contact the Enquiry Desk, Dr. Elsie Widdowson Library and Information Services, Food Standards Agency (020 7276 8181/8182 or at library&info@foodstandards.gsi.gov.uk).

See Also

• A03 Research Programme (A03)
• Food Working Party on Contact Materials

Contact: Paul Willetts
Tel: 020 7276 8540
Email: paul.willetts@ foodstandards.gsi.gov.uk