You should probably think twice (or thrice) before accepting coffee or tea on your next flight. According to a new airline food study from the Hunter College NYC Food Policy Center, it’s best to avoid drinking the water airlines use in flight. The results of this study, released in November, shouldn’t be too surprising given that, in 2004, an EPA investigation found disease-causing pathogens could be in the water of 15 percent of commercial planes.
So far, there have been no public reports of passengers getting sick from drinking in-flight coffee or tea — typically made from the same airplane tap water you avoid brushing your teeth with. However, planes will make emergency landings in instances of foodborne illnesses. (In 2011, American Airlines was sued by a family who alleged one of their family members died as a result of eating contaminated chickenserved on a flight.)
Airline beverages, it appears, can also be contaminated. Dr. Karen Joubert, PT, DPT spoke at a wellness summit in November where she cautioned against drinking the hot drinks offered on planes. She told TODAY Food that “it will not only increase dehydration but it is most likely loaded with bacteria.” Joubert, whose celebrity clients include Jennifer Aniston and Serena Williams, is sticking to bottled water until industry standards improve.
Currently, the Airline Drinking Water Rule, jointly regulated by the EPA, FDA and FAA, only requires disinfection and flushing one to four times per year, depending on the number of coliform samples taken per monitoring period. The ADWR was introduced in 2009 and has never been updated.
In essence, the water you drink is only as clean as the hoses and tanks used to transport and store it.
"You would think they’d be emptied and cleaned at least once a day," wrote Dr. Charles Platkin, PhD, JD, MPH, executive director of the Hunter College NYC Food Policy Center, in a 2018-19 airline food study. "But this is not so. So water is just sitting for long periods of time in what appear to be not-so-clean tanks." Platkin's study included a questionnaire about water sanitation practices sent to the following airlines: Alaska Airlines, Air Canada, American Airlines, United, Frontier, Delta, JetBlue, Hawaiian Airlines, Allegiant Air, Spirit Airlines and Southwest. While some of the airlines declined to respond, several did.
Delta said it disinfects its tanks four times a year and that taps and surfaces are cleaned between flights. In addition, Delta employees attend "drinking water service training" annually. United also cleans its water systems every 90 days. Both airlines rely on the ozonation disinfection method which involves adding oxygen to destroy bacteria and viruses. An American Airlines spokesperson, Ross Feinstein, told TODAY Food that American Airlines regularly tests and disinfects its fleet of catering carts, trucks and water tanks. Still, according to an anonymous flight attendant interviewed by Business Insider in 2017, it's not enough.
"Flight attendants will not drink hot water on the plane. They will not drink plain coffee, and they will not drink plain tea," said the flight attendant. In fact, the Association of Flight Attendants-CW takes partial credit for the existence of aircraft water regulations saying it pushed the EPA for them more than 16 years ago.
Another flight attendant told TIME Magazine in 2017 that only she and a few of her colleagues ever consider drinking the coffee they serve. And even then, it's only when they're desperate for caffeine.
"We only truly clean once a year. I’ve been on planes that are constantly running. It’s almost like a subway in New York. We know things are dirty in the system and it takes a little while to clean it out.”
But isn't dirty water safe to drink if it's boiled?
According to the New York State Department of Health, boiling is best defined as pasturization, not sterlization. Sterilization kills all organisms present. Pasturization, however, only kills organisms which harm humans, and only if the pasturization is effective. This is determined by temperature and time. So if the flight attendants are rushed or don't heat the water up to a high enough temperature, which can be tricky since elevation affects a liquid's boiling point, it could still be contaminated.
When TODAY Food reached out to Paul Dawson, a Clemson University food scientist and professor, and Brian Sheldon, an emeritus professor in food microbiology from North Carolina State University, they pointed out that the Hunter College Study was a questionnaire and didn't include any microbiological water testing. Instead, the co-authors of "Did You Just Eat That?" reference a 2002 Wall Street Journal study which actually included testing airplane water. The lab found strains of salmonella, Staphylococcus bacteria (which causes staph infections) and insect eggs in some of the samples.
Dawson and Sheldon said that even though the EPA acknowledges the problem and now regulates airline water, there are plenty of opportunities for contamination even before the water reaches the plane.
"First of all, airplanes fly to multiple locations and load drinking water at any of these destinations. Second, aircraft load water from airport watering points using temporary connections and finally, water may be stored at various locations at the airport and then transported to the plane in tanker trucks."
The two scientists recommend sticking to canned or bottled beverages if you want to be "extra safe" or if you have a compromised immune system. It may mean forgoing your in-flight caffeine or chamomile fix, but it also could mean forgoing nasty contaminants.