The greenest bags are plastic
Conclusions related to individual carrier bags The comparisons include the secondary reuse of 40% of lightweight bags (high density polyethylene [HDPE], HDPE pro degradant and starch polyester) as bin liners.
Conventional HDPE bag The conventional HDPE bag had the lowest environmental impacts of the lightweight bags in eight of the nine impact categories. The bag performed well because it was the lightest bag considered. The life cycle impact of the bag was dictated by raw material extraction and bag production, with the use of Chinese grid electricity significantly affecting the acidification and ecotoxicity of the bag.
HDPE bag with prodegradant additive The HDPE prodegradant bag had a larger impact than the HDPE bag in all categories considered. Although the bags were very similar, the prodegradant bag weighed marc jacobs slightly more and therefore used more energy during production and distribution.
Starch polyester bag The starch polyester bag had the highest impact in seve marc jacobs n of the nine impact categories considered. This was partially due to it weighing approximately twice that of the conventional HDPE bags, but also due to the high impacts of raw material production, transport and the generation of methane from landfill.
Low Density Polyethelene bag The LDPE bag has to be used five times to reduce its global warming potential (GWP) to below that of the conventional HPDE bag. When used five times, its impacts were lower in eight of nine of the impact categories. The impact was also substantially lower than the HPDE bag in terms of acidification, aquatic ecotoxicity and photochemical oxidation, due to lower shipping distances and the use of grid electricity that is less reliant on coal.
Paper bag The paper bag has to be used four or more times to reduce its global warming potential to below that of the conventi marc jacobs onal HDPE bag, but was significantly worse than the conventional HDPE bag for human toxicity and terrestrial ecotoxicity, d marc jacobs ue to the effects of paper production. However, it is unlikely the paper bag can be regularly reused the required number of times, due to its low durability. the number of uses required to reduce the GWP of the cotton bag to that of the conventional HDPE bag with average secondary reuse). The impact was considerably larger in categories such as acidification and aquatic and terrestrial ecotoxicity, due to the energy used to produce cotton yarn and the fertilizers used during the growth of the cotton.