A new study finds that plastic carrier bags have the lowest environmental impact. The Danish Environmental Protection Agency – part of the country’s Ministry of the Environment and Food – conducted an independent life-cycle assessment (LCA) of grocery carrier bags materials – and the results will surprise many: plastics were found to be the material with the overall lowest impact to environment. 

 

In an effort to reduce unnecessary waste and environmental damage, some countries have placed bans on plastic bags. The first to do so was Bangladesh, whose government imposed a total ban on the bag back in 2002. Since then, more than 40 countries worldwide have followed suit with a similar ban on plastic bags, including Rwanda, China, Taiwan and Macedonia. 

 

Kenya became one of the most recent nations to adopt such a ban: in August last year, the East African country implemented the world's toughest law aimed at reducing plastic pollution. Kenyans producing, selling or even using plastic bags today risk imprisonment of up to four years or fines of US$40,000. 

 

Yet new and surprising findings from the Danish Environmental Protection Agency (Miljøstyrelsen) – part of the country’s Ministry of the Environment and Food – seem to contradict the commonly held view of the plastic carrier bag as a scourge that needs to be outlawed over other forms of packaging. 

 

Analysis of seven materials

 

Last week, the Danish Environmental Protection Agency published a study that analyses the life-cycle environmental impacts of production, use and disposal of grocery carrier bags currently available in Danish supermarkets. The aim of the study was to identify the bag with the best environmental performance, the recommended number of reuses and the best disposal option of a grocery bag.

 

Seven materials (LDPE, PP, rPET, Polyester, biopolymer, paper, cotton and composite) and their variations were analysed in compliance with the international standards ISO 14040 and 14044 for a range of recommended environmental impacts, taking into consideration different end-of-life options: incineration, recycling and reuse as waste bin bag before incineration. For all carrier bag alternatives, the assessment took into account impacts arising from production of the carrier and its packaging (assumed to occur in Europe), transportation to Denmark, use, and disposal – which could occur in Denmark or within Europe.

 

Overall lowest environmental impacts

 

The main finding of the analysis is that, with regards to production and disposal, LDPE lightweight carrier bags provide the overall lowest environmental impacts for most environmental indicators when not considering reuse. In particular, between the types of available bags, LDPE carrier bags with rigid handles are the most preferable. The effects of littering for this type of bag were considered negligible for Denmark.

 

Another relevant finding was in respect to the best disposal option: the Study states “reusing the carrier bag as a waste bin bag is better than simply throwing away the bag in the residual waste, and it is better than recycling. Recycling can potentially offer benefits in the case of heavy plastic bags, such as PP, PET and polyester. Reuse as a waste bin bag is most beneficial for light carrier bags, such as LDPE, paper and biopolymer.” 

 

The LCA Study is accessible here: http://mst.dk/service/publikationer/publikationsarkiv/2018/mar/plastposer-lca/