A NEW study has revealed the grim reason you should avoid the hot drinks next time you’re on a plane.
For years, flight attendants have warned against it – and a new study has now backed up the claims.
Conducted by the Center for Food as Medicine and Longevity in the US, the 2026 Airline Water Study has analysed the quality of water on a number of airlines.
And the report found that a number of airlines were not up to the current water safety standards.
Looking at 10 major airlines and 11 regional airlines in the US, the quality of water was analysed over a three year period from 2022 to 2025.
Of the 35,674 sample locations for coliform (an indicator that pathogens may be in there) 949 tested positive for bacteria.
Not only that but 32 E.coli violations were found during the period – with E.coli potentially causing vomiting and diarrhea.
And while some airlines were found to have safe water – with Delta and Frontier coming on top – the majority of budget airlines fell short.
Charles Platkin, director of the Center for Food as Medicine and Longevity., said: “Nearly all regional airlines need to improve their onboard water safety.”
The study warns passengers to opt for sealed bottles of water, rather than unbottled plane water.
Not only that, but to avoid hot drinks including tea and coffee if they are made with tap water onboard.
Even washing your hands using the plane bathroom is advised against, with a hand sanitiser recommended instead.
Airlines must disinfect and flush out the water tank four times a year, or one a year but test it monthly.
Platkin previously said: “Planes come in, [and the tanks are] not being emptied and cleaned, because there is no time for that.
“The water tank is being filled on top [after] each usage. Whatever would be on the bottom stays there and sits there.”
Flight attendants have long warned passengers against drinks using the plane water tank.
Ex-cabin crew member Kat Kamalani explained on her TikTok account: “The reason being is that those water tanks are never cleaned and they are disgusting.
“So talk to a flight attendant, we rarely, rarely drink the tea or coffee, they come from the same water tank and so when you’re drinking that coffee and tea it comes from that hot water and it’s absolutely disgusting.”
Another anonymous flight attendant told 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.
Here are the best drinks you should have on a plane instead.