Throughout its life-cycle, a typical plastic will save seven times more greenhouse gas emissions (e.g. through material light-weighting or avoided food waste) than is emitted during its production. On average 15-20% of materials used in the construction of cars are plastics, saving around 5% in emissions compared to the use of alternative materials. Plastic packaging weighs just 10% of traditional packaging. This weight reduction significantly reduces transport emissions. If plastic packaging was not used to preserve food and drink, retailers would make at least 50% more truck journeys within the EU. Plastic also helps preserve food, minimising food waste. Without plastic packaging, the environmental impact of producing packaging, wastage of perishable products, and transportation of goods would increase.
However despite the many positive attributes of plastic, it does have significant negatives, namely:
Greenhouse gas emissions resulting from production and incineration after use
The degradation of the natural environment due to plastic pollution
In response to these negatives, Stäger commissioned a report from NNFCC to look at an array of polymers produced from renewable raw materials (biobased polymers), to see if they would firstly be suitable for their use, and secondly to establish whether by using them it would be better for the environment. This report was part funded by the European Union. NNFCC are experts in biobased products including polymers.
Stäger currently uses recycled PET made from 60-70% post-consumer waste. It serves the food, confectionery & toiletry industries with high-quality cartons & tubes.
The report studied nine potential biobased and/or biodegradable plastics, of which four were identified as potential replacements for PET for use in clear plastic packaging: polylactic acid (PLA), cellulose acetate (CA), piobased polyethylene terephthalate (PET) and polyethylene furanoate (PEF). A note of caution here, in that all four are, at present, significantly more expensive than the cost of recycled PET.
To ensure the environmental impact of these products is lower than traditional plastic, life cycle assessments can be undertaken. These assess an array of environmental impacts including those associated with human health, environmental health and resource use. As biobased plastics often use crop feedstocks, environmental impacts such as acidification and eutrophication tend to be larger than those of petrochemical origins. Non-renewable energy use and GHG emissions, however, tend to be lower.
Environmentally, biobased PET (30% biobased content) and PLA were both found to be better than petroleum PET, though neither were as beneficial as recycled PET. They do however have widespread commercial production and availability. LCAs were not available for CA or PEF. PEF is a new polymer yet to be commercialised; it has improved physical properties and is 100% biobased. The environmental impacts are envisaged to be lower than petroleum PET (but not recycled PET), LCA information prior to commercial release is anticipated.
CA and PLA are both compostable, PLA industrially, and CA at-home or industrially. Though possible, the recycling of these polymers is currently not established. The properties of these polymers are poor compared with PET and both have difficulty folding for rigid packaging. Biobased PET and PEF are effectively “drop-in” products for petroleum PET. Both can be recycled in current PET recycling facilities and processed in current production facilities. Their durability therefore also remains the same and if lost to the environment would contribute to the accumulation of plastic pollution.
In conclusion, continuing use of PET with high recycled content and biobased virgin material represents the best alternative to virgin petroleum PET vis a vis the four biopolymers studied, as dictated by life cycle assessment results. This then, in theory, seems to be the best route to take and provided the leeching out into the environment is minimised via better education, a uniform countrywide Council collection service, clear labelling, and much more high-quality UK-/European-wide recycling (rather than exporting to the Far East), it will continue to be the case. However, biopolymers that break down in the natural environment are still of interest to Stäger, and they will continue to explore them.
Source: NNFCC, press release, 2019-01-24.
Author: Oliver Goldsmith (NNFCC)