The British Glass Manufacturers Confederation (BGMC) made the statement as it challenged the findings of a survey that the environmental impact of polyethylene terephthalate (PET) was less than that of aluminium and glass.
The research, commissioned by Canadian company Husky, said PET production resulted in less greenhouse gas (GHG) emissions and used less energy than glass or aluminium cans.
But BGMC director general David Workman told FoodProductionDaily.com that the survey was flawed because it had not taken a number of vital considerations into account when calculating the overall carbon footprint of PET versus glass. While the environmental impact of glass may be top-loaded at the start of the manufacturing process, this decreases greatly the further downstream it travels in terms of recycling and the effects glass has if disposed of in the environment, he said
The first of the report’s defects was that the life cycle analysis (LCA) was only a “cradle to grave” examination, rather than a “cradle to cradle” one he explained. This meant the report failed to consider what happens to the container after it has been used. A cradle to cradle model factors in aspects such as recyclability- a particular strength of glass compared to plastics, said Workman.
“Therefore it can only be considered as a partial LCA,” he said of the research by consultants Allied Development Corporation.
“For its conclusions to be taken seriously it would have needed to have been a full "cradle to cradle" exercise - something that the plastics industry has shied away from, and for good reasons,” he added.
The UK glass industry, he said, recycled 60 per cent of its waste stream, with 60 per cent of this material being used to make new bottles and jars.
“It is a process that can be repeated ad infinitum,” he said. “We have a verifiable audit trail that proves that our recycled content figure for glass packaging range between 45 per and 55 per cent dependent on whether process waste is included.”
The inert nature of glass is another significant characteristic that should be included in any proper environmental assessment, he said.
“Glass is an inert material and therefore does not taint products filled into it nor do any environmental damage if, after use, it gets into landfill or our rivers and oceans,” said Workman.
Glass bottles also offer a longer shelf life on most products and “as a result helps to prevent food and drink waste, which does far more environmental damage than all forms of packaging”, he claimed.
Glass can be considered greener because its raw materials are plentiful and locally sourced. The fact that more post consumer waste is used to make new containers further reduces its environmental impact, said the trade chief.
“All of these factors make glass the most sustainable of all packaging materials and need to be included in any meaningful life cycle analysis,” he concluded.