Some providers go so far as to suggest that PVA polybags are not made of plastic. For example, in an article about one such product, one provider claimed that their “products are not made out of actual plastic.”
So it is important to preface this debate by clarifying whether PVA is actually a plastic or not. To do this, the first simple step should be to consult a dictionary. How is the term ‘plastic’ commonly defined? The truth is, many definitions of ‘plastic’ can be found, with varying degrees of complexity, but the key elements are nearly always the following: it is formed of polymers (chains of many molecules) and is able to be moulded or shaped, typically in the presence of heat and/or pressure, and possibly contains additives.
In terms of a legal or regulatory definition, the EU attempted to come up with its own definition of what both a plastic and a single-use plastic is. The EU’s Single-Use Plastics Directive defines a plastic in the following way: “A material consisting of a polymer […], to which additives or other substances may have been added, and which can function as a main structural component of final products, with the exception of natural polymers that have not been chemically modified”.
Based on these criteria, it is evident that PVA is a plastic. PVA is a polymer that is capable of being moulded or shaped (in this case, into a thin film). By the EU definition, it is also the main structural component of the product and it is also not an unmodified natural polymer. PVA therefore fits both the typical linguistic usage of the term ‘plastic’ and the legislative use of the term.
The fact that some forms of PVA have the property of being water soluble film suppliers at specific temperatures, does not exclude it from being a plastic. Plastics can indeed have many different properties. For example, it is entirely possible to have a petroleum-based plastic that can easily biodegrade in home composting conditions. So whether a material is a plastic or not does not tell us anything about its biodegradability, solubility or generally about its environmental impact.
This discussion around plastic illustrates once again that one of the key selling points for novel materials is that brands want to cater to the increasing customer desire for ‘plastic-free’ or ‘sustainable’ products. As covered in many of our previous articles, this has lead to a range of opportunities for suppliers to sell materials to brands under the pretense of being sustainable or brands advertising products to consumers as more sustainable than they really are.
One interesting example for this is the British outdoor brand Finisterre. A major producer of PVA for plastic bag applications, whose material is known for being used to make water-soluble polybags used by Finisterre (amongst others), describes its PVA as a plastic. In the marketing copy for the Finisterre polybag, the brand highlights that it is “different to traditional plastics” while being careful to never explicitly state that the bag isn’t plastic. Their main claim however is that this new plastic bag is “eliminating the final piece of single-use, non-degradable plastic from our packaging”. This claim is questionable by most definitions though (including the EU’s Single-Use Plastic Directive), as this is still a single-use plastic product. It is used once, it is made from a plastic, and it is disposed of at the end of its life. Isn’t that the definition of a single-use plastic?
In fact, this is a key issue with the marketing of PVA-based hot water-soluble polybags: that they are suggested to be a solution to single-use plastics. This is certainly a bold claim which needs further scrutiny.