A glossary of food contact materials and key terms

Food contact materials, or FCM

Wax Is used as treatment and coating of primary FCM such as paper, board and aluminium. It may also be used to coat food directly, such as in the case of fruit and cheese, in which case it is edible. Paraffin waxes are a mixture of saturated hydrocarbons. UV light and heating can lead to the degradation of waxes. Consequently, some antioxidant may be added to improve the functionality. In addition, plasticizers and water proofing agents might be added. Waxes are used as food packaging material because they have good moisture barrier characteristics. As such they can protect dry foods from environmental moisture or reduce moisture loss from wet food.

Per- and polyfluoroalkyl substances (PFASs) The use of per- and polyfluoroalkyl substances (PFASs) in products started in the 1950s. PFASs increase the repellency of oil, grease and water. Popcorn bags, fast food wrappers, pizza boxes, and other packagings that need to be oil-repellent and/or heat resistant are often coated with PFASs. PFASs are also excellent for thermal and chemical stability. These features make PFASs highly suitable for a variety of FCMs. PFASs resist against degradation in biological organisms and in the environment. Few perfluorinated compounds have been eliminated, but others continue to be used for FCM.

Can coatings Cans are made of three different materials: aluminum, tin-coated steel and chromium coated steel. Cans are typically coated internally and externally with thin films (1 to 10 µm) that protect the integrity of the can from effects of the food and prevent chemical reactions between the metal and the content. Epoxy-based coatings have the highest market share of more than 90%. However, food companies have started to replace BPA-based epoxy coatings with alternatives, following some toxicological evidence and recent regulations. Acrylic and polyester coatings are currently used as alternatives and, more recently, polyolefin and non-BPA epoxy coatings are being used. Further inventions include BPA capturing systems and top coatings. These alternatives are usually more expensive than epoxy coatings.

Other can coatings Oleoresins, Vinyl, Phenolic, Acrylic, Polyester, Polyolefins

Printing inks Printing inks on food packagings serve for consumer information (the label) as well as for marketing purposes. Inks may migrate onto the inner surface of FCM. Some materials such as glass and plastic may also be printed or dyed themselves. Some external packagings can be equipped with printed labels, such as in the case of PET bottles. Finally, inks may be present within the bulk material when we recycle paper. The biggest concern about recycled paper is the presence of mineral oil. Due to the non-accurate recycling of food contact paper and board used in other applications, mineral oils will mix with the bulk material even if mineral oils are not used as FCM. Thousand of chemicals can be used as inks, a serious problem for laboratories and regulatory agencies.

Terms and definitions

FCM: Stands for food contact material, the material that directly makes contact with foods/drinks.

Multilayer packaging structures: Are made of different materials aimed to give barrier properties, strength and storage stability to food. Each layer provides them one functionality, mainly barrier properties but also, sealability, active properties. The material of construction of multilayered packaging ranges from paper to plastics to metals.

Nanocomposites: Polymeric matrices incorporating well-dispersed nano-reinforcements aimed to barrier, thermal and mechanical properties.

LDPE and HDPE: Low- and high- density polyethylene are synthetic materials, extensively used. Milk, juice, and water bottles, grocery and garbage bags, and bread and frozen food bags are some of the uses of polyethylene.

PP*: Polypropylene, is used when heat resistance is needed. Yogurt containers and margarine tubs are applications of polypropylene. Trays, yogurt cups, frozen food bags and cake boxes are applications of polystyrene.

PET: Is among those plastics which are an important part of your everyday life. Because polyethylene terephthalate is an excellent water and moisture barrier material, plastic bottles made from PET are widely used for mineral water and carbonated soft drinks.

PVDC: Polyvinylidene chloride, has been used as a barrier in fresh meat packaging for decades, but increasing environmental concerns are urging packaging producers and retailers around the world to revisit its use and develop viable alternatives.