How is PET different from other plastics?

PET is the one plastic which has the correct balance of properties ideally suited for packaging carbonated (fizzy) drinks like colas and lemonades. All plastics are porous to some degree and will allow gasses to pass through the structure given sufficient time.  PET will retain sufficient carbon dioxide in a beverage bottle to keep the drink fresh within the normal shelf life of the product, which is not true for other widely available plastics. The same property also keeps oxygen outside the container and prevents spoilage from oxidation.

Why should PET replace glass? Glass is also very impermeable.

Glass has proved an outstanding material for packaging liquids for well over 1000 years. However, in today's modern world the demand for safer, more environmentally sustainable and cost effective packages that can be easily transported  led to the development and growth in the use of PET bottles. Glass is environmentally sustainable for smaller sized specialist bottles, but when filled with carbonated drinks in containers over 1.0 litres - PET is the safest and most preferred lightweight and unbreakable container.

How do I distinguish PET from other plastic bottles?

Virtually all plastic cola and sparkling mineral water bottles are made from PET. Usually the PET container is marked with an identification symbol in the form of three arrows making a triangular shape, a number 1 in the centre of the triangle and the acronym PET under the base of the triangle. The symbol can be found either printed on the label or moulded on the base or shoulder of the bottle.

Can the PET bottle be recycled similar to glass?

Yes it can.  Some PET is collected, washed free of contaminants and reclaimed in a similar manner by remelting and making new bottles and containers. However, most of the PET collected is still recycled back into polyester fibres for textile materials, for the filling of duvets and similar bedding, in sports garments and shoes, and indoor and outdoor wear, furnishing textiles, insulation, belts and webbing, filters and geotextiles. [See under recycling].

PET must use up more energy than glass if it is made from oil so why should it be used as an alternative?

Simply comparing manufacture of a glass and a PET bottle is misleading, it is necessary to compare what they are being used for, both are used to deliver drinks or liquids to the consumer and when compared on resources used to deliver one litre of beverage the situation is rather different.

Pre-cooked foods are now sold in PET trays suitable for reheating in conventional or microwave ovens is this also normal PET?

The PET grades used for 'ovenable' trays have the same basic chemical formula as ordinary PET but it has been specially heat treated during the container manufacturing process to turn it opaque milky white. In this form it has a much higher temperature resistance and is can be heated up to 220 degrees centigrade which is high enough for reheating pre-cooked foods.