Dishwasher Dilemmas

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By Daniel Pedersen, Ph.D., Director of Science & Standards

New headshot2Which Dishwashers and Washers Are  Better: High Heat or Low Temperature ?
A couple of weeks ago, I got an email from Cerise Bridges, our Certification Specialist, who conducts certification reviews for service providers: hotels and cleaning companies. She makes sure that our certified service providers meet the requirements in our standards, but she also hears from clients about the challenges they face. This email posed a question that often comes up from Green Seal-certified hotels, because our standard, GS-33, does not address this issue directly:

“Low temp laundry and dishwasher systems vs. high temp systems. With the low temp systems hotels can save energy and water but health codes will usually require them to use a sanitizer or chlorine bleach. The high temp systems use more energy and water but bleach is not required. Hotels are conflicted and ask which is better – using more chemicals but saving energy and water or using fewer chemicals.”

So… seems like a simple question, right? But as it usually turns out when talking about sustainability, the answer is: “It Depends…” Or more to the point: “There’s no Single Right Answer (TM)

When it comes down to it, this is really one of those trade-offs that we have to make among competing priorities. Each person has to decide what is more important:

  • Is it the depletion of resources (fuel, electricity and water) and emission of air pollution and greenhouse gases?
  • Or is it the use of materials that might be potentially hazardous to our health and cause water pollution?

The answer could very well depend on where you live, or how sensitive your staff or guests might be to certain chemicals. In an area with heavy water pollution (such as the Chesapeake Bay watershed) the water pollution concern may have more weight.
On the other hand, you might prefer to limit the use of water in a desert, where water resources are scarce, or reduce emissions of air pollutants in areas with poor air quality.
Our standard, GS-33, leaves this choice up to the individual. If I had to choose, I’d probably go for saving energy and conserving water, but make sure to reduce my use of bleaches, finding safer and effective alternatives, and protecting the users with gloves and proper ventilation.
But other people might decide differently based on cost, convenience or which environmental issues they consider to be most important.
Never simple…!!

Now what would you decide…and why?