Paper towels v. hand dryers: a life cycle assessment

Working in sustainability, it is amazing how often I am asked which is environmentally better: paper towels or hand dryers. This isn’t as simple a question as it may seem. Instead of giving them the one-or-the-other answer they are after, I launch into a lecture on life cycle assessment and the complexities that this question actually entails.

Superficially, it’s easy to see pros and cons of each hand drying technique.  Paper towels are made from a renewable resource, but there is embedded energy and resources in their production, they create waste that is not recyclable through normal co-mingle or paper recycling systems (but perhaps through organic streams – something that is rarely done), and they also incur ongoing inputs.

Hand dryers on the other hand (pardon the pun), don’t need ongoing materials, but do have more materials embedded in building them, and they require electricity to run.

When you pull it apart further, you soon see that there are more questions left unanswered than have been answered. Where are the raw materials in the paper towels from? What chemicals and energy went into the production process, and how sustainable are they? Where were they produced and how far did they have to travel throughout the production and distribution processes to get into your office bathroom? And for hand dryers, how much energy do they use? How long are they set to run? What type of energy does the organisation source (black power, GreenPower or onsite solar, or something else?)?

And there are behavioural considerations. Do people use more than one paper towel each time, or do they use the hand dryer more than once, and for how long each time?

The solution to solving this actually quite complex question is using a life cycle assessment (LCA). A study by Joseph et al. in 2012 found that hand dryers are more efficient than using two paper towels (based on use of a particular machine and scenario). Similarly, Building Green found that energy-efficient machines were preferable to paper towel when considering full life cycle impacts. Perhaps not at all surprisingly, a study commissioned by Dyson found their dryer to be the most efficient (Montalbo et al 2011).

However, another important factor to consider is how hygienic these techniques are – because after all, the goal is to clean your hands. If the two environmental options don’t actually offer the same utility at solving the core goal, is there really a need for a LCA? Research suggests paper towels are superior and recommended by the World Health Organisation. Check out this video:

So does this make the debate over paper towels v. hand dryers irrelevant? Should it be paper towel all the way? But what about the waste? and raw materials?

Perhaps we should all carry our own cloth hand towel at all times! But what are the life cycle implications of all that washing?!

This age-old LCA quandary remains.

 

References

Cascades Canada ULC, 2012, ‘Towel or dryer? The importance of hand hygiene (Cascades – Canada version), Cascades.com, https://www.youtube.com/watch?v=8udRZaea5g8

Builing Green, 2011, ‘Paper Towels vs. Efficient Hand Dryers: New Study Makes the Choice Clear’, Building Green.com, https://www.buildinggreen.com/blog/paper-towels-vs-efficient-hand-dryers-new-study-makes-choice-clear

Joseph, T., Bah, K., Jahanfar, A. & Dubey, B. 2015, ‘A comparative life cycle assessment of conventional hand dryer and roll paper towel as hand drying methods’, Science of the Total Environment, vol. 515-516, pp.119-117.

Montalbo, T., Gregory, J. & Kirchain, R. 2011, ‘Life cycle assessment of hand drying systems’, Dyson, http://msl.mit.edu/publications/HandDryingLCA-Report.pdf

Image source http://www.buffalo.edu/content/dam/www/reporter/2014-photos/05/Hand-dryer-sampling.jpg

 

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