Paper Cup vs. Styrofoam Cup: Which is the Greener Choice?

There is no such thing as a Styrofoam®™ cup! (See further explanation at http://craft.dow.com/about/cup.htm.) I will, however, give my opinion on the question as to whether paper cups or plastic foam cups are "greener". If we assume that both end up in a landfill, I believe that neither has a "green" advantage. The paper will only biodegrade minutely, but the porosity of the plastic foam will allow it to compress more to take up a smaller volume. Since the plastic foam cups are more functional in their original use (especially since you have to double cup the paper ones and still burn your hand), I think that we should stick with them.

What we need is a foam plastic made from plant products which will rot when buried. Not paper cups or plastic based on oil.

That is the common misconception. Making items that will be discarded out of biodegradable material doesn't help the garbage accumulation problem, since air is required for biodegradation to occur, and air is excluded from landfills by design. The right solution is to either make things strong enough and with flexible utility so that they can be reused and therefore never make it to the landfill, to dispose of them via other methods such as composting or burning (intentional degradation), or to reduce the compacted volume as much as possible so that the landfill doesn't fill up as fast.

You seem to know a lot about the topic, well I am doing a project for Science Expo and I was thinking about using paper cups or 'plastic foam cups' i only have until january to perform about 3 tests.... What would you suggest I do? If you don't mind me asking. More like what do you think I should test because I already know how I am performing the experiment.

Hello "Guest". I don't really have a lot of time to dedicate to coming up with ideas for this right now, but I didn't want you to feel ignored. Assuming that you are trying to compare the two types of cups, I would suggest possibly the following tests:

1. Insulation capacity - Basically, compare how well they each maintain the temperature of their contents (either hot or cold) over time. The temperature on the outside of the cup could also be noted, as this is what often makes people use two cups for one serving.

2. Weight / Volume per unit - This would be more of a measurement than an experiment, but it does indicate differences in transportation costs. You would likely need to use entire sleeves of cups to make it more easily measurable. Basically, you would be trying to compare the transportation cost per cup.

3. Crushed volume? - I don't know how you would do this, or what it might tell you. It is important as it determines how much room each cup will take up in a landfill. You would have to some duplicate what happens to the cup in the landfill, and then somehow measure the final volume (perhaps with water displacement?)

Biodegradation rates are not really relevant, since in an actual landfill, neither would biodegrade at an appreciable rate. This would not be demonstrable in the period of time available for your experiments.

I hope this helps at least a little bit.