When people think of free amenities they might associate it with the perks of staying at an all-inclusive resort or hotel. Everyone loves getting stuff for free and airlines actually offer numerous amenities free of charge, including things like blankets and pillows. But, these free items can actually be harmful to our health and can make us sick.

Airplane passengers may be shocked to learn that those free amenities they'll find on their seat or seatback pocket are actually infested with germs and bacteria. And, don't be fooled by items wrapped in plastic because those aren't actually cleaned, either.

There are 12 things aboard a plane that passengers should not bother using, but for things like entertainment screens and tray tables, it's a good idea to carry a few disinfecting wipes to wipe them down.

Check out these 12 free amenities on a plane that even flight attendants stay clear of.

12 Airplane Blankets Are Not Washed Or Just Reused

Airplane blankets might sound like a fantastic free amenity on long flights, but a 2007 investigation by The Wall Street Journal revealed that airlines cleaned these blankets every five to 30 days. Passengers should bring their own blanket or bring warmer clothing.

11 Seatback Trays Are The Most Dangerous

Thought the airplane bathroom was the germiest thing on a plane? Well, you'd be surprised to learn that the dirtiest thing on a plane is that seatback tray you're using. In-between flights, airline staff do a quick clean-up, but that doesn't necessarily mean they're disinfecting each and every tray. Passengers should bring along disinfecting wipes and wipe them down themselves.

10 Passengers Tend To Forget About Air Vents

Passengers tend to forget that germs also lie on those air vents above their heads. With so many people touching them to turn it on and off there are loads of bacteria. Passengers should use a cloth or disinfecting wipe to touch the nozzle since it's a good idea to have fresh air blowing germs away.

9 Magazines And Menus In Seatback Pockets Are Loaded With Germs

The Canadian Broadcasting Corporation found that the seatback pocket had the second-highest level of bacteria on it after the headrest and was also full of E.coli. So passengers may want to think twice about reading the in-flight magazine or putting their belongings in the pocket.

8 Touchscreens Are Very Dirty

A great amenity on a long flight is the entertainment screens so passengers can watch movies and TV shows. But these screens are really dirty, especially with so many other passengers touching them. If you want to use them, you should wipe them with a disinfectant

7 Tea Or Coffee Is A No-Go

A new study suggests that passengers should avoid asking for coffee or tea on a plane because it can contain harmful bacteria. Not even the flight attendants drink any hot beverage on a plane so that unfortunately tells us a lot about how dangerous the water can be.

6 Pre-Packaged Pillows Aren't Clean

Just because a pillow or blanket is wrapped up in plastic does not mean it is clean. In 2000, Royal Airline Laundry, which supplies pillows and blankets to some of the top airlines was accused of repackaging these items without properly cleaning them. Just think about all the past passengers drooling and cleaning off their hands and faces with these free amenities.

5 On-Board Water Isn't Safe

Water that isn't in a sealed bottle is not safe to drink aboard airplanes. Tap water is stored in water tanks that are not cleaned as often as they should be and the water is contaminated with harmful bacteria. Can you guess the airline that got the score for the worst water quality? It was a tie between JetBlue and Spirit.

Related: 15 Strange (But True) Facts About Airplane Seats

4 The Coveted Aisle Seat Has The Most Germs

Everyone wants the aisle seat because they can easily get to the bathroom without bothering their neighboring passengers and get off the plane quicker. However, the aisle seat, especially its armrest and headrest can carry germs and bacteria because other passengers tend to touch those areas when they walk back and forth.

3 Water Fountains Are Covered In Germs

Instead of purchasing a water bottle at the airport shop that cost an arm and a leg, passengers can easily carry a portable water bottle and refill it at water fountains. However, passengers should be aware that these fountains carry the most germs on its button that dispenses the water since these are rarely cleaned.

Related: These Travelers Had Super Weird Experiences At Airports

2 Foam Ear Parts On Free Headphones Are Not Replaced

Just like the free blankets and pillows, the headphones that flight attendants hand out aren't actually cleaned. According to flight attendants, the foam ear parts which are found on free headphones are hardly changed or replaced. A flight attendant urges passengers to rip the foam once you use them so that they must replace them.

Related: 10 Things Flight Attendants Have To Say About Working At Spirit Airlines

1 Self-Check Machines Are Hardly Wiped Down

Passengers have to do everything by themselves these days, including printing out their own boarding pass and luggage tags.  While this may make it easier and faster for passengers to get to their gate, thousands of people touch these screens and they're hardly ever wiped down.

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