Ask Pablo: Metal vs. Plastic Cutlery

Plastic fork laying on the ground

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Dear Pablo: Which type of silverware is better for the environment: stainless steel or plastic? My office uses disposable everything and I am trying to make a change.

Variations of this question have been asked and answered in this column before. Of course the answer does not just lie in the manufacturing of the materials for disposable and durable goods such as plastic and metal cutlery. This is also a question of how they will be used and cleaned. Years ago I was asked if it's better to wash dishes by hand or use the dishwasher. I collected some empirical data on my clunky old dishwasher to find that washing by hand is better. Meanwhile, a German study using the new energy-efficient dishwashers showed that they can use half the energy, one sixth the water, AND less soap. The question of disposable dishes, cups and cutlery has been a recurring theme as well. In my very first Ask Pablo article ever I did a life cycle analysis of sorts comparing paper cups, ceramic mugs, and metal coffee mugs. Later I revisited the matter in more detail. The key to the question of durable vs. disposable lies both in the production of the product and in its use. The eco-efficiency of reusable cutlery depends on the cutlery being used many times over many years to take the place of hundreds of plastic forks, knives or spoons. Where the disposable cutlery beats the reusable is in the fact that it does not need to be washed. Over long-term use however, the reusable cutlery's manufacture becomes so insignificant that we can say that it is negligible. The comparison therefor turns into the energy and water required to wash the reusable cutlery vs. the energy and water used to produce, transport and dispose of a plastic cutlery.

Consider the Impact of Washing Metal Cutlery

The impact of washing cutlery has many dimensions. If washed by hand it will require less energy and water than using an old dishwasher, but more than a brand new state-of-the-art model. The efficiency with which you load the machine becomes important because every cubic centimeter counts but you don't want it packed so full that flatware and dishes come out still dirty. The California Energy Commission has the following tips on their website:

  • Avoid using the "rinse hold" setting on your dishwasher. "Rinse hold" uses three to seven gallons of hot water for each use, and heating water takes extra energy. Never use "rinse hold" for just a few dirty dishes.
  • Try to wash only full loads-the savings will surprise you.
  • Use short cycles for everything but the dirtiest dishes. Short cycles use less energy and work just as well.
  • If your dishwasher has an air-dry setting, choose it instead of the heat-dry setting. You will cut your dishwasher's energy use from 15 percent to 50 percent. If there's no air-dry setting, turn the dishwasher off after its final rinse and open the door. The dishes will dry without using any extra electricity.
  • If you rinse dishes before loading them, use cold water. Don't waste water by letting it run continuously, either.
  • Install your dishwasher away from your refrigerator. The dishwasher's heat and moisture make the refrigerator work harder. If you have to put them next to each other, place a sheet of foam insulation between them.

Consider the Impact of Manufacturing and Disposing of Plastic Cutlery

Disposable cutlery has even more complexity. They can be made from plastic or agricultural plastics. These utensils must be manufactured, packaged and transported over great distances to their final destination. After this long journey from its source the cutlery is used for about ten minutes before being unceremoniously dumped into a trash can without much care. Food contamination makes it unlikely to be recycled or even recyclable. From here the used cutlery is most likely transported by garbage truck to its final resting place in a big hole in the ground, the landfill. Here it will sit for thousands of years of years, never decaying (or in the case of bio-plastic, decaying only slowly, if conditions are right, and turning into the potent greenhouse gas methane).

The Bottom Line on Cutlery

A lengthy quantitative exercise would end up being approximately correct at best, but probably closer to precisely wrong. The problem is that an analysis using my dishwasher and one particular set of utensils would result in an answer that is completely different from your dishwasher and your disposable cutlery. In most cases the reusable cutlery and the dishwasher will win over disposables. Disposables may still have their place; at the company picnic, or any other event that is far removed from modern plumbing. Ultimately trust that little green voice inside your head that tells you that disposable cutlery are the wrong choice for the office meeting. If other people don't share your values and are too lazy to load their flatware and plate into the dishwasher, perhaps the committed few can organize and volunteer for dish patrol. Eventually your corporate culture can evolve and everyone will be on board with the new status quo.