There is some controversy regarding whether plastics manufacturing should be considered as a major consumer of oil given that some processes rely primarily on oil by-products rather than crude oil. Can anyone direct me to data on the ecological footprint and/or energetics of plastic bags, especially polyethylene terephthalate (aka PET, PETE, etc)? In particular, I want to understand how much energy is actually embodied in a plastic bag, including the manufacturing feedstocks, manufacturing processes and the transportation cycles (typical for North America). Any insights appreciated,
Neil
The Footprint and Energetics of Plastic Bags?
Sign in or Sign up to comment
Has anyone come up yet with the carbon footprint of plastic and paper grocery bags used once?
Marion
Hi Marion,
Check out the following resource... http://people.bath.ac.uk/cj219/ (fill out the form to access the report) Look at page 6 - generally, plastic bags used in retail are of the LDPE film variety (confirm?). As such, it has an embedded GHG emissions ratio of 1.9 kg CO2e per kg of bags. Another source suggested that each bag weighs between 6 and 10 grams (http://www.cpia.ca/film/news.php?ID=327), so a kg of bags is likely in the neighbourhood of 100 to 165 bags. This suggests that according to this study, a single bag has an embedded carbon footprint of 11-19 grams of CO2e. Let me know if my math has gone sideways. With these data points it should be fairly straight forward to derive the GHG emissions profile of any policy or communications effort that leads to a given amount of local bag use/reductions.
Cheers,
Ted Battiston
Manager of Sustainability Initiatives
Resort Municipality of Whistler
604.935.8205
[email protected]
www.whistler.ca
www.whistler2020.ca
Hi Ted,
Your analysis is based upon the same source that I used. I used a more conservative figure for LDPE products generally (1.7 Kg), rather than the LDPE film figure (1.9 Kg). I suspect your choice of figures is probably closer to the truth. Also, the bags consider in my analysis are the smaller transparent bags used for fruit and veg. The larger opaque shopping-type bags are closer to six grams, according to the Canadian Plastics Industry Association.
Cheers,
Neil
...
Last week I requested data on the embodied energy of plastic bags. Embodied energy is the energy consumed during the life time of a product. Engineering professors at University of Bath have been working on a database to determine the embodied energy and carbon of a large number of common materials, including a full range of plastics. If you need it, follow the link below. http://www.bath.ac.uk/mech-eng/sert/embodied/
Cheers,
Neil