Some teabags produced using alternative materials like polylactic acid (PLA) are not as biodegradable as advertised.
PLA, derived from resources like corn starch or sugar cane, was the centerpiece of a recent study that assessed its environmental impact.
Three compositions of PLA were examined in teabags that were buried in soil for seven months.
Various analytical techniques were used to evaluate their degradation.
Teabags entirely made of PLA did not break down, while those mixed with cellulose broke into smaller pieces, losing 60% to 80% of their mass, yet the PLA remained intact.
The effect of these teabags on Eisenia fetida, a key earthworm species for nutrient recycling, was also studied.
Exposure to different concentrations of teabag fragments led to increased earthworm mortality and negatively impacted their reproduction.
The study’s authors call for clear disposal instructions on product packaging.
Only one manufacturer in the study indicated that their teabags were not compostable at home, potentially leading to improper disposal.
Dr. Winnie Courtene-Jones pointed out the pressing need for more research on biodegradable plastics like PLA.
She stressed the importance of disposing of these materials properly to avoid creating new environmental problems.
Analytical methods such as size exclusion chromatography, nuclear magnetic resonance, and scanning electron microscopy were used for this study.
These techniques allowed for in-depth examination of the physical and chemical changes in the teabags over time.
Labels such as “biodegradable” and “compostable” can mislead consumers.
Accurate, clear information on disposal is essential.
Professor Antoine Buchard emphasized the need for collaboration among scientists, policy makers, and manufacturers to ensure proper standards and prevent public confusion.
This study is part of BIO-PLASTIC-RISK, a project from the University of Plymouth, which investigates the breakdown of biodegradable products and their impact on terrestrial and marine species.
Previous research echoes these findings, showing some biodegradable products don’t disintegrate even after years in the environment.
Discussion on the Global Plastics Treaty continues, most recently during the fourth session of the Intergovernmental Negotiating Committee (INC-4).
Despite global consensus on plastic pollution, alternative materials still enter the market without proper guidance.
Professor Richard Thompson expressed concern about the disposal of these alternative materials.
Even with proper disposal knowledge, only about half of UK households can access suitable composting facilities. Learning from past mistakes with plastics is crucial.
Dr. Mick Hanley added that PLA-based teabags did not fully degrade and can harm composting worms.
Clear labeling is critical to prevent these materials from contaminating garden soil, potentially impacting wildlife and plant growth.
