Welcome to the first in a series of Meeting Myth-busters which try to answer some of the recurring questions I get related to event sustainability.
Today’s question comes from Sarah Shaheen of Oracle Marketing, who contacted me recently about choosing reusable mugs for hot drinks at an event. Sarah was working with a venue who pushed back against her request for ceramic mugs, claiming that manufacturing and cleaning the mugs caused greater environmental impact than using disposables.
It’s difficult to answer Sarah’s question with 100% accuracy, but we can provide some good guidance on when to push back against the push back about reuse. To answer the question, it’s helpful to set aside the idea that one option is always “good” or “bad” in every situation. Because it takes 70 times more energy to make a ceramic cup than a foam cup, it’s better to shift your thinking to ponder how many times you need to reuse a ceramic mug in order to buy-back its higher manufacturing footprint compared to disposables, including what it takes to wash the cup. Hocking (1994) proposed the break-even point for a ceramic cup is 1,006 uses when compared to foam, and 39 uses when compared to paper.
Recent commentators have suggested the breakeven point may be lower today, given improvements in dishwasher energy efficiency, although it’s unclear if these have out-paced efficiency improvements in factories that manufacture disposables. Critics are also quick to point out that the 1994 study does not consider disposal impacts, which would likely drive down the break-even point, particularly for paper.
A more recent analysis by Carbon Clear considered the emissions produced by 2,000 uses of reusable or disposable cups. Ceramic cups emerged as the most carbon-sensitive choice if you take into account the manufacturing and washing footprint. This study also includes emissions from disposal and volume of landfill, broadening the original scope of Hocking’s research. Paper had the greatest carbon impact, followed by foam and ceramic.
What does it all mean for Sarah? That the best type of hot beverage cup to use at an event depends on risk of breakage and if you expect them to be returned for reuse. If you anticipate your mug will be used at least 40 times then it’s likely a better option than paper. This is highly likely if you’re meeting in a hotel or restaurant. To make it a better option than foam you should aim for approximately 1,000 reuses, possibly less. Something that is definitely possible for an office staff room, restaurant or hotel, but possibly a stretch for an outdoor festival, very large event or facility without carpeted floors. In these situations where reusables aren’t always feasible, it is important to select disposables that you are able to keep from landfill. This almost always eliminates foam as an option as it cannot be composted and can rarely be recycled. Compostable paper cups may therefore be an acceptable fall-back position where ceramic mugs can’t be used (provided you are able to compost it).
Good luck Sarah! And don’t forget to remind the venue reusables can save them money!
Have a meeting myth you’d like busted? Comment and perhaps someone has the answer!
Eventcellany 
Hi Eventcellany,
I work for Canopy in Australia who specialise in offsetting events. It’s a fascinating game-working out what should be assessed, how to do it and measuring the carbon cost of so many things- from air flights to wristbands. We’d like to talk with people about what we do as there so few of us about.
Indeed scoping is an important question – thanks for raising it. What should you include in your calculation or not? What makes sense for you to pay for as an organiser and what might make sense to have sponsored, or involve attendees to pay for? It can be complicated for a planner who isn’t familiar with carbon accounting and the complicated terms involved. So an outside party like an offset company can help make it easier to calculate and strategise about how to be accountable for what can’t be reduced.