A former flight attendant has warned passengers to never drink the complimentary coffee or tea while on-board a plane.
Kat Kamalani, a former cabin crew member from the United States, revealed her golden nugget of advice in a video shared to her TikTok, where she has amassed almost 900,000 followers for her tips, tricks and inspirational content.
The video, which at the time of writing appears to have either been deleted or made private, urged travellers to avoid drinking hot beverages on aeroplanes due to the condition of the water tanks.
According to outlets who viewed the video - which had garnered millions of views before being taken down - Kamalani said flight attendants will "rarely" consume hot beverages while working, claiming the tanks are "never cleaned".
"Don't you ever consume these products from an airline - just promise you won't," she said.
"Never consume any liquid that's not in a can or a [sealed] bottle, the reason being is because those water tanks are never cleaned. They are disgusting."
She also claimed the coffee machines on-board aircrafts are "rarely cleaned" unless they are broken.
"The kettles are cleaned in-between flights but the [coffee] machines are never cleaned... and they're by the lavatories," she added.
For parents hoping to prepare a bottle of warm milk for their baby, Kamalani explained a simple alternative if they're wanting to avoid the hot water.
"Never ask for hot water for your baby's bottle," she said. "Ask for bottled water on the side, hot water in a cup, then make your baby's milk with the bottled water, put it in the cup then heat it up."
In 2019, the Airline Water Study - conducted by the Hunter College NYC Food Policy Center at the City University of New York and DietDetective.com - analysed the quality of drinking water across 10 major airlines.
The study found the quality of drinking water varies by airline, with many possibly providing passengers with contaminated tap water.
The airlines were given a "water health score" ranging from five - the best - to zero - the worst - based on 10 different criteria. Any score above three indicated relatively clean drinking water, but alarmingly, seven of the 10 tested airlines scored a zero, one or two.
The study concluded that passengers should "never drink any water on-board that isn't in a sealed bottle", noting that the tap water on both major and regional US carriers was found to be contaminated with varying levels of E. coli and coliform.
It's not clear why Kamalani has appeared to remove the video.
In a separate clip shared to her TikTok last week, she revealed the five things she would never do as a former flight attendant - a video that has racked up more than 4.2 million views.
In the footage, which appears to have been filmed at an airport, Kamalani reiterated that she would never drink the hot water on an aeroplane - which came in at number two on her list.
Other tips included always having snacks on-hand and avoiding sharing too much personal information with fellow passengers.
As per Time magazine, the United States Environmental Protection Agency (EPA) requires airlines to clean out their tanks and test their public water systems for the presence of coliform and the potentially deadly E. coli bacteria at least once a year, or up to four times per year.