Coffee is the Grossest Thing Aboard Airplanes — Besides the Lavatories?

“Coffee. Don’t drink the coffee on airplanes. It’s the same potable water that goes through the bathroom system”, according to this article pertaining to ten questions you always wanted to ask a flight attendant which supposedly reveals what an anonymous flight attendant told Justin Caffier of Vice. “We recently had a test for E. coli in our water and it didn’t pass, and then maintenance came on and hit a couple buttons and it passed. So, avoid any hot water or tea. Bottled and ice is fine, of course.”

Coffee is the Grossest Thing Aboard Airplanes — Besides the Lavatories?

Aside from the fact that the word potable means safe to drink, the water aboard airplanes — which is used in coffee by some airlines — is generally not safe to drink.

“Unless the source of the water used for hot drinks is either bottled or not from airplane itself — or, at least, is hot enough to have been boiled — it may not be completely safe to drink. Zach Bjornson — also known as FlyerTalk member T-wiz and the son of FlyerTalk member l’etoile — took samples of water from different commercial aircraft on a trip back in 2002 and used them as part of a science project at the age of 13 years old. His persistence and innovative results found — among other things — insect eggs that days later in the lab hatched into maggots; and The Wall Street Journal published his experiments and findings. I briefly revisited the potability of water aboard commercial aircraft in this short article posted on Friday, June 25, 2010 here at The Gate.”

If the team of people at a water disinfection company has it their way, water dispensed aboard airplanes will be considered completely potable due to the use of ultraviolet light disinfection technology and could render the use of bottled water served aboard many airplanes by flight attendants obsolete — which could potentially be good news for passengers who are thirsty but do not want to pay up to three dollars for water.

“It could work, but hasn’t been certified for efficacy yet”, according to Bjornson, who is an immunologist and microbiologist who earned his doctor of philosophy degree at Stanford University School of Medicine. “Disinfection is typically difficult. The tricky thing with UV is that normal bulbs have varying output and the output is not usually metered, so you can’t tell if they’re working easily. I’m not familiar with UV LEDs. I’m skeptical that enough UV radiation could be emitted for point-of-use; usually contact time with UV radiation is minutes I think. We would need to see more info from the vendor.”


Also included in the article pertaining to ten questions you always wanted to ask a flight attendant are revelations of the best way to get seat upgrades and other freebies — as well as what is the worst part of the job of being a flight attendant. For some reason, I personally doubt the veracity of the information of that article; but if you have been a reader of The Gate for a long time, you already knew about avoiding the consumption of anything containing water aboard an airplane unless the water came from a bottle.

Before you do order coffee or tea — or anything else containing while aboard an airplane, you may want to first ensure that bottled water is being used instead of water from the system of the aircraft…

…but I do agree with one item in that article: lavatories can be the grosses places aboard airplanes — especially on transoceanic and other long-haul flights.

If you are wondering why the photograph at the top of this article shows coffee mugs in a hotel room instead of aboard an airplane, that is because you may not want to drink out of them or glasses due to the way they are “cleaned”; and in addition, the coffee maker is supposedly one of the six germ “hot spots” in your hotel room.

Photograph ©2015 by Brian Cohen.

6 thoughts on “Coffee is the Grossest Thing Aboard Airplanes — Besides the Lavatories?”

  1. JEM says:

    “It’s the same potable water that goes through the bathroom system”.

    Why is this an issue? The same is true of my kitchen and bathroom at home, and at nearly every home or hotel I’ve ever stayed at. The concern should be whether the water is contaminated, for which one anecdote does not constitute evidence of a general problem, nor does an uncontrolled experiment conducted by a 13-year old sixteen years ago constitute anything like objective evidence of current conditions. FWIW, water tests can fail for many technical reasons that don’t indicate that E. coli is present – the FA’s report that the test passed after maintenance pushed a couple of buttons could indicate such a non-contamination problem.

    No idea why the FA dismisses ice as a source of contamination, either. Commercial ice machines regularly breed bacteria, the bags are handled by multiple people, and even if it’s initially uncontaminated, remaining so depends on FAs correctly handling it during the entirety of prep and serving, ensuring they never touch it, or let any other potentially contaminated item (such as a scoop or a cup they’ve handled without gloves) touch it at any point.

    Personally I’ll try to refrain from paranoia, and continue to drink both coffee and soft drinks with ice on planes without giving “germs” a second thought.

    1. Brian Cohen says:

      Contamination is an issue because of the water tanks and lines of an airplane which may not always be regularly or properly cleaned, JEM — not because of the water itself.

      As for ice, I understand that the self-service machines in hotels are notorious for harboring bacteria. I may do some research on that an post the findings in a future article.

      By the way, I rarely consume ice — only because I do not like the way it eventually waters down a drink…

      1. JEM says:

        Of course it’s the water, but the FA appeared to try to justify her alarmism by referencing the lavatory.

        As for not regularly or properly cleaning tanks, do you have any evidence for your assertion? The best studies I can find are similar to this one reported by the National Institutes of Health ( which concludes that (a) no samples found dangerous bacteria (e.g., E. coli, Legionella, etc.), (b) some samples found low but above standard levels of non-dangerous bacteria (which could potentially be a problem for immunocompromised individuals, but not those who are relatively healthy), and (c) where those non-dangerous bacteria were found, the primary sources appeared to be from the airport service vehicles, not the cleaning of the aircraft tanks.

        In my experience, all of these levels are much less important than whether the flight attendant properly washes his or her hands (with airplane potable water) prior to touching the inside of my cup as she removes it from the stack.

        I’ve also seen FAs rip open a bag of ice (with unknown, but probably low-level contamination) and dump it into an intermediate container without taking measures to ensure the ice doesn’t contact the outside of the bag or their unwashed hands.

        I’m not saying that it isn’t important to be concerned about various sources of contamination. Just that, when you’re confined in a tube with hundreds of other people shedding millions of microbes per minute into the air around you, and being served food and drink brought to you by humans working in a cramped, shaking galley located 2 feet from a common lavatory, there are far more likely sources of things to kill you or make you sick…

        1. Brian Cohen says:

          The only evidence I have are numerous articles in which flight attendants cite the reasons why they refuse to drink the water aboard airplanes, JEM — which is why I wrote that “the water tanks and lines of an airplane which may not always be regularly or properly cleaned.”

          I do not disagree with you, JEM. People would probably never eat in restaurants or catering halls again if they saw how poorly the food was handled at some of them. Traces of insects, feces and other contaminants which are permitted by law are embedded pervasively in our food supply — even at home…

          …and then there are all of the dust mites we breath in on bed linens and blankets — both at hotels and at home.

          I suppose that the analogy may be similar to dental practitioners who walk out of the room when using one of those old X-ray machines to take photographs of the teeth of a patient: those flight attendants do not want to regularly drink the water aboard airplanes, as they would expose themselves to the contaminants more than passengers…

          …but as you said, many other sources of contamination which can cause illness exist aboard airplanes — yet somehow we survive.

          One other thought: you know from reading The Gate that I completely agree with you about the importance of washing hands…

  2. Glenn says:

    The same potable water system in your house supplies both the bathroom and the coffee maker. Do you not drink the coffee at home? People who insist on using bottled water for their coffee are contributing to world pollution. As far as UV light disinfection, it is now used at the majority of water treatment plants in the U.S. with flows of thousands of gallons per second. This is done instead of using chlorine as there can be problems with chlorates for long-term use. It would be a great idea to install this on planes. Consulting a licensed Civil Engineer would be a better solution than a microbiologist.

    1. Brian Cohen says:

      I do not drink coffee, Glenn

      …and I am on record in saying that the tap water in New York City is amongst my favorite water in the world to drink — and I do not care what it goes through on its way to the faucet…

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