Terms & Links

“What most people see in their garbage cans is just the tip of the material iceberg: the product itself contains on average only five percent of the raw materials involved in the process of making and delivering it.”
- Source: Cradle to Cradle, William McDonough & Michael Braungart. Page 28.

Terms & FAQ’s

Q: What is the difference between home and industrial compost?

Residential or backyard composting means that an individual household composts most of its food and yard waste in a container located outside the home. This is the simplest and most cost-effective method because collection and transportation costs are avoided. People benefit directly from their own efforts by producing a valuable additive for their own garden soil.

However, not all food and yard waste can be managed so simply. This is where centralized or industrial composting fits in. Industrial composting involves significantly larger quantities and a larger variety of organic wastes.

Organic material is collected and transported to a special facility where it will be prepared and processed into compost. Industrial compost facilities are better able to control oxygen, moisture, and temperature. They typically maintain temperatures above 130°f which allows for the breakdown of some materials that require consistently higher temperatures, such as PLA.

Q: What is the difference between biodegradability and compostability?

Biodegradable: material that will degrade from the action of a naturally occurring microorganism, such as bacteria, fungi etc. Biodegradable material is not necessarily compostable, as the residue may be toxic and is, therefore, not considered compostable.

Compostable: materials capable of undergoing biological decomposition in a compost site, to the extent that they are not visually distinguishable and break down to carbon dioxide, water, inorganic compounds, and biomass, at a rate consistent with known compostable materials (eg cellulose). Compostable materials leave no toxic residue and therefore, the resulting humus is a safe and healthy contribution to soil.

Q: What is the difference between recycling and composting?

Recycle/Reuse: Minimizing waste generation by recovering and reprocessing usable products that might otherwise become waste (.i.e. recycling of aluminum cans, paper, and bottles, etc.).

Source: http://www.epa.gov/OCEPAterms/rterms.html


Composting: The controlled biological decomposition of organic material in the presence of air to form a humus-like material. Controlled methods of composting include mechanical mixing and aerating, ventilating the materials by dropping them through a vertical series of aerated chambers, or placing the compost in piles out in the open air and mixing it or turning it periodically.

Source: http://www.epa.gov/OCEPAterms/cterms.html



Q: What does HDPE, LDPE and PET stand for?

HDPE - High density polyethylene


LDPE - Low density polyethylene


PET - Polyethylene terephthalate


PP - Polypropylene


PS - Polystyrene


PVC - APolyvinyl chloride



Q: What are those numbers on the bottom of plastic products? Do they mean how many times the plastic has been recycled?

The numbers inside the recycle symbol indicate what material the product is made from:

Polyethylene Terephalate Ethylene - PETE goes into soft drink, juice, water, detergent, and cleaner bottles. Also used for cooking and peanut butter jars.


High Density Polyethylene - HDPE goes into milk and water jugs and bleach bottles.


Polyvinyl Chloride - PVC goes into window cleaner, cooking oils, and detergent bottles. Also used for peanut butter jars and water jugs



Low Density Polyethylene - LDPE goes into plastic bags and grocery sacks, dry cleaning bags and flexible film packaging. Also some bottles.



Polypropylene - PP goes into caps, disks, syrup bottles, yogurt tubs, straws and film packaging.



Polystyrene - PS goes into meat trays, egg cartons, plates, cutlery, carry-out containers and clear trays.



Other - Includes resins not mentioned above or combinations or plastics.


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Q: What is PLA or Bio Plastic?

“Polylactic acid or polylactide (PLA) is a biodegradable, thermoplastic, aliphatic polyester derived from renewable resources, such as corn starch (in the U.S.) or sugarcanes (rest of world). Although PLA has been known for more than a century, it has only been of commercial interest in recent years, in light of its biodegradability.”
“The new plastic (PLA) has a few quirks however. The biodegradable materials won't break down in regular landfills; they have to be taken to special industrial sites and treated like compost. Nor will they decompose in home compost bins: Temperatures there don't reach the required 284 degrees F. Yet the containers will melt if filled with hot food, or placed in the dishwasher or microwave.”
- Source: Liz Nakazawa, Special to The Christian Science Monitor, Portland, Oregon. www.csmonitor.com/2003/0904/p12s02-sten.html
“So-called bio-based plastic has its own environmental downside, (however). Corn farmers rely heavily on fossil-fuel based fertilizers and pesticides to grow their crops, for example.”
- Source: “One Word of Advice: Now It's Corn Plastics Manufactured From the Plant Grow More Appealing Amid Soaring Oil Prices,” Thaddeus Herrick, Staff Reporter, The Wall Street Journal, October 12, 2004

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Links

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