Eco-Profile of Compostable Plastic

The environmental advantages of plant-based plastics over petroleum-based plastics are measurable and significant.

All of World Centric®’s plastic products are made from compostable, renewable, plant-based resins. These plastics are not hazardous or toxic during production, and when they are discarded into commercial composting facilities, they decompose completely into carbon dioxide, water, and biomass. These qualities exert a much lighter environmental impact than the qualities of petroleum-based plastics, which are virtually never compostable, derive from non-renewable resources, are hazardous and toxic during production and cast massive amounts of pollution into our world.

Consider the tables below, which compare the environmental impacts of products made from plant-based plastics with the impacts of those made from petroleum-based plastics.

Plant-based plastic (PLA) vs. petroleum-based plastic (PS)

Comparing Eco-Profiles of Plant-based (PLA²) plastic products with Eco-profiles of Petroleum-based (PET ^{3, 4}, PP³, and PS³) plastic products

Manufacturing plastic resins from raw materials: Comparative ratios among the production of different resins

	PLA plastic made from corn	PET plastic (polyethelene)	PP plastic (polypropelene)	PS plastic (polystyrene)
Energy consumption ratio = 1.0 : 1.9 : 1.7 : 2.1
Water consumption ratio = 1.0 : 0.9 : 0.6 : 2.5
CO2 emissions ratio = 1.0 : 2.2 : 1.3 : 1.
Solid waste production ratio = 1.0 : 2.1 : 0.7 : 2.7

Manufacturing production materials from raw materials: Direct measurements of manufacturing one pound of wheat-straw, tree-based, and Styrofoam materials

	PLA plastic made from corn	PET plastic (polyethelene)	PP plastic (polypropelene)	PS plastic (polystyrene)
Energy consumption (kwh)	5.37	10.28	9.34	11.28
Water consumption (gal)	8.29	7.45	5.12	20.54
CO2 emissions (lb)	1.30	2.81	1.67	2.51
Solid waste (lb)	0.042	0.087	0.029	0.113

Manufacturing products from plastic resins: Comparative ratios among products made from different resins

	PLA plastic – injection molding	PET plastic – injection stretch blown molding	PP plastic – injection molding	PS (polystyrene) – injection molding)
Energy consumption for injection molding, ratio = 1.0 : 0.5 : 1.6 : 1.9
CO2 emissions from injection molding, ratio = 1.0 : 0.3 : 1.2 : 1.8

Manufacturing products from plastic resins: Direct measurements of manufacturing one pound of products from each resin

	PLA plastic – injection molding	PET plastic – injection stretch blown molding	PP plastic – injection molding	PS (polystyrene) – injection molding)
Energy consumption for injection molding (kwh)	6.30	3.14	10.27	11.93
CO2 emissions from injection molding, (lb)	1.87	0.63	2.24	3.28

> Back To Eco-Profiles of Compostables

Page Notes

1. Urban Forestry: Carbon Sequestration Workbook, Energy Information Administration, U.S. Department of Energy, ftp://ftp.eia.doe.gov/pub/oiaf/1605/cdrom/excel/urbfor05.xls, 2005.
2. Eco-profiles for Current and Near-future NatureWorks Polylactide (PLA) Production, Vink Ervin, NatureWorks, http://delivery.sheridan.com/index.php?ID=GEN_114998_EP-, 1 November 2007.
3. What’s Your Process Energy Fingerprint? Robin Kent, Plastics Technology, http://www.ptonline.com/articles/whats-your-proces..., March 2009.
4. Eco-profiles of the European Plastics Industry: PET Injection Stretch Blow Molding, Plastics Europe, http://www.plasticseurope.org/plastics-sustainabil..., February 2010.
5. • Assuming 625 items of cutlery per year (12 per week);
   • 12.38 pounds of cutlery per year (5.5 g per item);
   • 3.17 lb of CO2 emitted per 1.0 pound of PLA cutlery (1.30 lb from material production + 1.87 lb from product production);
   • 5.79 lb of CO2 emitted per 1.0 pound of PS cutlery (2.51 lb from material production + 1.87 lb from product production);
   • 32.44 lb less CO2 in a year from 625 items of PLA cutlery than from 625 items of PS cutlery ((12.38 x 5.79)-(12.38 x 3.17));
   • 4.4 trees would absorb 32.44 lb of CO2 in a year, assuming an average of 7.38 lb of CO2 absorbed per tree per year.
6. U.S. Household Electricity Report, Energy Information Administration, U.S. Department of Energy, http://www.eia.doe.gov/emeu/reps/enduse/er01_us.ht..., July 14, 2005.
7. • Assuming 625 items of cutlery per year (12 per week);
   • 12.38 pounds of cutlery per year (5.5 g per item);
   • 11.67 kWh to produce 1.0 pound of PLA cutlery (5.37 kWh for material production + 6.30 kWh for product production);
   • 23.21 kWh to produce 1.0 pound of PS cutlery (11.28 kWh for material production + 11.93 kWh for product production);
   • 142.87 kWh less in a year for 625 items of PLA cutlery than for 625 items of PS cutlery ((12.38 x 23.21)-(12.38 x 11.67));
   • 4.9 days for an average household to consume the same amount of energy, assuming consumption at 29.19 KWh per day.

Sources

Eco-profiles for Current and Near-future NatureWorks Polylactide (PLA) Production, Vink Ervin, NatureWorks, http://delivery.sheridan.com/index.php?ID=GEN_114998_EP-, 1 November 2007.
Eco-profiles of the European Plastics Industry: PET Injection Stretch Blow Molding, Plastics Europe, http://www.plasticseurope.org/plastics-sustainabil..., February 2010.
Plastics and Sustainability: Browse Life Cycle Analisis (LCA) by Product List, The Plastics Portal, http://www.plasticseurope.org/plastics-sustainabil..., retrieved August 2012.
Urban Forestry: Carbon Sequestration Workbook, Energy Information Administration, U.S. Department of Energy, ftp://ftp.eia.doe.gov/pub/oiaf/1605/cdrom/excel/urbfor05.xls, 2005.
U.S. Household Electricity Report, Energy Information Administration, U.S. Department of Energy, http://www.eia.doe.gov/emeu/reps/enduse/er01_us.ht..., July 14, 2005.
What’s Your Process Energy Fingerprint? Robin Kent, Plastics Technology, http://www.ptonline.com/articles/whats-your-proces..., March 2009.