New study finds biodegradation-promoting additives for plastics to be ineffective

The study was posted by the American Chemical Society as a “Just accepted” manuscript on 27 February 2015 under the title “Evaluation of Biodegradation-Promoting Additives for Plastics”.

As the authors note: “Biodegradation-promoting additives for polymers are increasingly being used around the world with the claim that they effectively render commercial polymers biodegradable. However, there is a lot of uncertainty about their effectiveness in degrading polymers in different environments.”

This study is therefore an attempt to put some of this uncertainty to rest by investigating the effect of biodegradation-promoting additives on the biodegradation of polyethylene and polyethylene terephthalate. The effects of three different types of biodegradation-promoting additives on the biodegradation of a blend of linear low and low-density polyethylene (commonly used for bread, supermarket and trash bags) and PET sheets under active anaerobic digestion, aerobic degradation (compost) and soil burial environments were investigated. The 3 additives selected consisted of an oxobiodegradable additive, a non-oxo additive and one that was a combination, and were manufactured by Symphony (d2w), Ecologic (Eco-one EL 10), and Wells Plastics Ltd. (Reverte for PE). Controls without additives were also produced. According to the authors, the base experiments evaluated all 3 types in all 3 environments for PE, and both available additives in all 3 environments for PET, to provide further understanding of the effect of disposing these polymers in the environment.

Interestingly, it was found that none of the five different additives tested significantly increased biodegradation in any of these environments. Thus, no evidence was found that these additives promote and/or enhance biodegradation of PE or PET polymers. So, as these authors write: “Anaerobic and aerobic biodegradation are not recommended as feasible disposal routes for non-biodegradable plastics containing any of the five tested biodegradation promoting additives.” (KL)


Evaluation of Biodegradation-Promoting Additives for Plastics
Susan E. M. Selke, Rafael Auras, Tuan Antoine Nguyen, Edgar Castro Aguirre, Rijosh Cheruvathur, and Yan Liu
Environmental Science & Technology Just Accepted Manuscript
DOI: 10.1021/es504258u

http://pubs.acs.org/journal/esthag