Toilet Paper Calculations

The University of Ottawa celebrates RecycleMania with the launch of toilet paper, uOttawa raises awareness about food waste

RecycleMania has launched at the University of Ottawa, and indeed around North America, and this year we are using a new tactic that we picked up from our friends over at Penn State Sustainability. It's called Toilet Paper. Basically every 2 weeks we are posting infographics about food waste and recycling in the washroom stalls around campus.

The beauty of this approach is that we basically have a captive audience. The downside is that we get complaints about using paper to promote recycling. But rest assured that we did do a lot of thinking before we decided to post paper... Here are our findings.

Large Posters vs. Small Posters

We considered using large posters to spread the word about food waste and found that because of their positioning on the walls, the visibility of most posters is low and they are rarely read. Numbers vary wildly, but it could be assumed that between 4% and 8% people that pass by a poster will read it.

Conversely, nearly 100% of posters posted in washrooms are read by the occupants. You are kind of stuck in this space with not much else to do... a captive audience as it were.
That’s a potential 25 fold difference in effectiveness!!!
And in terms of paper, we can produce 2 – 3 small posters for each large poster so in order to have the same effectiveness, the small posters win hands down.

We also have the problem of wanting to convey a lot of information about food waste. This usually requires a bit of concentration and having posters in a space where you aren’t going to be doing much else makes more sense. Reading an infographic while walking through a hall likely won't produce the desired retention of information.

Plasma Screens

We considered posting the messages on plasma screens and found that not only are they also rarely read, they produce more carbon on average than a printed sheet of paper.
Screen = 7.6 g of CO2 / hour of electricity used
Paper = 6g of CO2 per sheet (the piece of paper + the printing process)

*A 2013. 50" plasma screen consumes 0.19 kWh according to Energy Star
*The Ontario Electrical grid produces 40 g of CO2 for every kWh

Over the course of a day, a screen in the Dining Hall will produce 182.4 g of CO2. That means we could produce 30 posters a day and still be on par with just one screen.

We intend to leave each poster up for 2 weeks so while the one screen will have produced 2.55 kg of CO2, the 200 posters we intend to print for the entire campus will only create 1.2 kg of CO2.

*This doesn’t include the energy required to recycle the paper vs the screens at the end of their lifecycles.

Do Nothing

We also considered the idea of doing nothing. I mean why not, seems like it would be the best for the planet, right?

Even though we have a zero waste Dining Hall, that doesn't mean that people aren't wasting food by composting a bunch things they should be eating. Well, approximately 771 kg of food is wasted in the Dining Hall each day. Let’s be generous and say that 50% of that stuff is just things like fruit rinds and napkins (and this is a very generous number). Then we have about 385 kg of food waste a day.

If these posters can save:
  • 1 kg of Beef = 27 kg of CO2 = 4,500 posters
  • 1 kg of Potato = 2.9 kg of CO2 = 483 posters
  • 1 kg of Lentils = 0.9 kg of CO2 = 150 posters
If the 385 kg of food waste produced every day were just lentils, we would be able to produce 57750 posters a day and still create less CO2.


Ideally, I don't want to have to create any posters to raise awareness about food waste. But, as it turns out, I am not as smart as I wish I was. So if you have any ideas about what we can do to be more environmentally sensitive while raising awareness, I want to hear them. I am certain that we can work together to create a world where food waste and paper waste are a thing of the past.

~ jON - Campus Sustainability Manager