Plasticizers are substances that are added to some hard plastics to make them softer and more flexible. Most plastics used for food packaging do not contain any plasticizer at all. Of the common plastics used in packaging, PVC (poly vinyl chloride) is the only one that may contain a plasticizer. Plasticized PVC is widely used for a range of applications from flooring, via shoe soles and shower curtains to medical tubing and bags for intravenous drip solutions. In food contact applications, plasticized PVC is used for some cling films and in gaskets and seals for bottle caps and lids.
Because of the widespread use of plasticizers in food contact and medical applications, they are among the most extensively studied substances around in relation to health and safety. The plasticizers used for food packaging applications have the approval of the major health and safety authorities such as the Food & Drug Administration (FDA) and Environmental Protection Agency (EPA) in the USA as well as European food safety authorities.
Many plastic containers have a polymer identification numbers embossed on the base, sometimes within a triangle made from three arrows. The purpose of these symbols is to assist in sorting plastic containers for recycling. They were first recommended by the Society for the Plastics Industry (SPI) in the USA and have been adopted widely throughout the world. The use of the symbols is voluntary and it must be stressed that the purpose is to identify the type of plastic used. They are not a claim for recyclability. Whether a particular container or material can be effectively recycled or not, depends on local conditions.
1.PET Fizzy drink bottles, fruit juice, water and cooking oil bottles, some clear dishwashing liquid bottles, clear trays and punnets.
2.PE-HD Milk bottles, bottles for bleach and other household chemicals, bottle caps, buckets, crates and grocery bags.
3.PVC Some clear bottles and trays, some cling films and industrial applications such as gutters and piping.
4.PE-LD Most general purpose clear soft films and bags, some cling films, frozen vegetable bags, milk sachets, and soft squeezable bottles and caps.
5.PP Margarine and yoghurt containers, bottle caps, reusable food storage containers.
6.PS Some yoghurt and ice-cream tubs, disposable cups and glasses. Foamed protective packaging.
7.Other Engineering plastics and containers from mixed materials that cannot be readily recycled.