# Biodegradable and Compostable Shopping Bags under Investigation by FTIR Spectroscopy
###### Abstract  
In the recent years, plastic-based shopping bags have become irregular and progressively replaced by compostable ones. To be marketed, these \"new plastics\" must possess suitable requirements verified by specific bodies, which grant the conformity mark, and the approved physicochemical properties are periodically verified. The fast, inexpensive, non-destructive, easy to use, and reproducible Fourier-Transform infrared (FTIR) spectroscopy is a technique routinely applied to perform analysis in various industrial sectors. To get reliable information from spectral data, chemometric methods, such as Principal Component Analysis (PCA), are commonly suggested. In this context, PCA was herein performed on 4, 5, and 21 \(\times\) 3251 matrices, collecting the FTIR data from regular and irregular shopping bags, including three freshly extruded films from the Italian industry MecPlast, to predict their compliance with legislation. The results allowed us to unequivocally achieve such information and to classify the bags as suitable for containing fresh food in bulk or only for transport. A self-validated linear model was developed capable to estimate, by acquiring a single FTIR spectrum if, after the productive process, the content of renewable poly-lactic-acid (PLA) in a new produced film respect the expectations. Surprisingly, our findings established that among the grocery bags available on the market, irregular plastic-based shopping bags continue to survive. plastic-based shoppers; compostable shoppers; conformity requirements; efficient prediction; Fourier-Transform Infrared (FTIR) spectroscopy; Principal Component Analysis (PCA); predictive linear model +
Footnote †: journal: Medical  
to marine life are primarily mechanical due to ingestion of plastic debris and entanglement in packaging bands, synthetic ropes and lines, or drift nets. Plastic particles were found in the stomachs of 8 out of the 11 seabird species caught as bycatch. Marine debris affect a significant number of species, including at least 267 species worldwide, 86% of all sea turtle species, 44% of all seabird species, and 43% of all marine mammal species [4]. Additionally, there is also potential danger to marine ecosystems from the accumulation of plastic debris on the sea floor. Consequently, to address this issue, governments have introduced specific restrictions and, meanwhile, the goal of limiting the release of plastic into the environment has become an area of growing global scientific interest [5]. In this context, the EU Commission has drafted the \"Packaging and Packaging Waste Directive 94/62/EC\", concerning the use and re-use of plastic bags, that was later amended by the \"Directive (EU) 2015/720\", which focused on the consumption of light-weight bags (less than 50 \(\upmu\)m thick), whose use was no longer free for costmers. This later legislative document calls for EU Member States to undertake initiatives aiming at reducing the average annual consumption of plastic bags to 40 per person by 2025 [6]. However, long before the European procedures, national policies against plastic bags were adopted in some countries. Germany and Denmark introduced taxes for importing and producing non-biodegradable products in the early 90, Ireland in 2002, while even earlier in 1988, Italian law imposed a tax to importers and producers of non-biodegradable products [7]. Furthermore, with the legislative \"Decree 152/2006 (Testo Unico Ambientale)\", Italy banned plastic bags. In particular, following repeated interventions by the Italian legislator, since 2011, a ban on non-compostable bags was decreed and their gradual replacement with certified compostable bioplastic bags was enabled [8]. As regards light-weight plastic bags, the ban was adopted in January 2013 anticipating the \"Directive (EU) 2015/720\" [9]. With the legislative \"Decree 91/2014\" [10], the Italian government obliged producers to market light-weight biodegradable bags according to UNI EN13432 of 2002 [11].