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.

Transport distances are also now growing as consumers request specialised drinks from outside their own local boundaries. PET offers substantial savings in transport fuel costs, reduced carbon footprint and less wastage through breakage over the glass equivalent.