The survey - Compostable Packaging: The Reality on the Ground – also found four out of five composters said the introduction of a standardized labelling system for compostability would significantly improve both the ease of processing packaging material and therefore its recovery rate.
The aim of the research was to shed light on how compostable packaging is actually treated in the United States and provide recommendations for improvements in the way it is treated, said the SPC.
The survey of 40 industrial composting facilities was triggered by confusion within the packaging industry over how plants treat food packing waste. Many packers believed facilities rejected material citing it as a contaminant to their composting process and finished product, said the green packing group.
The SPC also found that the growing number of individual facilities, as well as different regional and state compostability standards, meant packaging designers and engineers were uncertain of how to approach compostable packaging.
“There is a disconnect between compostable packaging design and the composting facilities who deal with those materials,” said SPC project manager Liz Shoch.
The research found that 90 per cent of facilities questioned actively accepted compostable packaging. However, more than two thirds required some type of standard or certification before allowing it in the front gate.
Paper cups with polyethylene lining, mixed paper and clay-coated paperboard were items identified as being least likely to be accepted by composters.
A further issue was the difficulty facility staff had in distinguishing between compostable and conventional products – particularly after shredding - which led to the fear of contamination of the end product.
Some 82.5 per cent of facilities flagged up the need for a standardized labelling system – such as color coding or a clearly visible logo – as a scheme that would be “one of the most significant areas for improvement”.
Some composters also accused packaging companies of ‘greenwashing’ by misleading consumers with unsubstantiated claims about biodegradability, said the SPC.
“This includes packaging that is only partially biodegradable or labels that neglect to mention the long time frame needed for complete biodegradation,” added the report. Such practices can lead to contamination of compostable products.
However, packagers have also raised concerned that some sites rejected packaging that met the American Society for Testing and Materials (ASTM) standards. The SPC report suggested bringing all the appropriate industry and regulatory players together to hammer out a “cohesive and effective labelling outreach program”