We assume that recyclable stainless steel was good and

plastic was bad, but we can't just make assumptions like that.

We're doing rigorous sustainability thinking, so

we need to test our assumptions.

In this lecture, we'll do a life cycle assessment to see whether the reusable

stainless steel bottle is in fact better than a disposable plastic bottle.

To remind you of the situation, a Brita Hydration Station would be purchased and

employees would be given reusable stainless steel water bottles.

The company would wash the bottles once a week for employees.

Over the course of the year, this combination would replace

24,000 half liter, so that's 16.9 fluid ounce,

plastic water bottles, 24,000.

Here's some data I found out about these bottles.

The stainless steel bottles each weigh about 210 grams and

each of the plastic bottles weighs 13.3 grams.

So the total weight of the materials for

an entire year is 52.5 kilograms of stainless steel or

319.2 kilograms, if you use the plastic bottles.

The weight of the materials is important,

because that's how we'll compute the environmental impact.

It's on a per kilogram basis.