top of page
Search

That Fountain Drink Might Be Dirtier Than You Think, PFAS, Bacteria & More

  • Jan 26
  • 4 min read


PFAS, Bacteria, & What’s Really Lurking Inside Soda Machines

PFAS, Bacteria, & What’s Really Lurking Inside Soda Machines


Fountain drinks are everywhere: fast food counters, gas stations, movie theaters, and office cafeterias. They’re cheap, fast, and feel harmless. Press a button, get a fizzy reward. But behind the scenes, soda fountain machines have a bit of a reputation. And it’s not great.


Over the years, researchers have repeatedly found that fountain drink dispensers can harbor bacteria, sometimes at levels that raise legitimate hygiene concerns. At the same time, scientists and regulators are sounding the alarm about PFAS, so-called “forever chemicals”, in water systems that feed these machines.


So what’s actually in your cup? And should you be worried? Let’s break it down.


First, a Quick PFAS Refresher (because yes, they’re everywhere)


PFAS, short for per- and polyfluoroalkyl substances, are a massive group of human-made chemicals designed to be extremely durable. They repel water, oil, grease, and heat, which is why they’ve been used in everything from non-stick pans to waterproof jackets to food packaging. That durability is also the problem.


PFAS don’t break down easily. They build up in the environment and in our bodies over time, which is why scientists often call them “forever chemicals.” Research has linked PFAS exposure to:


  • Immune system suppression

  • Hormonal & metabolic disruption

  • Elevated cholesterol

  • Liver damage

  • Developmental issues in children

  • Increased risk of certain cancers


Drinking water is one of the most common ways people are exposed, especially in areas near industrial sites, military bases, or older infrastructure.


So… Can PFAS Show Up in Fountain Drinks?


There’s no viral study titled “Your Coke Is Full of PFAS” yet. But experts say there are very real pathways for PFAS to end up in fountain beverages.


1. The Water Supply

If the water feeding a soda machine contains PFAS, and many municipal systems do, those chemicals can carry straight into the drink unless advanced filtration is in place.


2. Older Machine Components

Some older beverage system parts (think tubing, seals, coatings) were historically made using PFAS-related materials. While many manufacturers have moved away from them, legacy equipment is still out there, especially in older restaurants and convenience stores.


3. The Supply Chain

PFAS contamination has been detected in food processing environments and packaging. That means contamination can happen long before the syrup ever hits the machine. The FDA is actively studying PFAS in food and beverages, but the science is still evolving, and regulation is playing catch-up.


The Bigger, Messier Issue: Bacteria in Soda Machines


If PFAS are the slow-burn concern, bacteria are the immediate red flag.

Unlike PFAS, microbial contamination in fountain drink machines is well-documented. Multiple studies have found that soda fountains, especially poorly maintained ones, often contain bacteria you probably don’t want in your drink.


What researchers keep finding


  • Coliform bacteria, which signal sanitation problems

  • DNA from organisms like E. coli, Salmonella, Pseudomonas, Klebsiella, & Staphylococcus

  • Yeasts and molds that thrive in sugary, moist environments


A widely cited study from Loma Linda University found that more than 40% of soda fountain water samples tested positive for coliform bacteria.

Not exactly refreshing.


Why Soda Fountains Are Basically a Bacteria Playground


Fountain drink machines are kind of the worst of all worlds when it comes to hygiene:


  • Sugar residue feeds microbes

  • Moist, dark interiors encourage growth

  • Water often sits stagnant overnight

  • Internal tubing is rarely cleaned as often as it should be

  • Biofilms (aka slimy bacterial communities) form & cling to surfaces


Even if the nozzle looks clean, bacteria can be thriving deeper inside the system, completely out of sight.


What Does This Mean for Your Health?


The Bacterial Angle


For most healthy adults, drinking from a contaminated fountain once in a while probably won’t cause noticeable harm. But for kids, older adults, pregnant people, or anyone with a weakened immune system, exposure increases the risk of gastrointestinal illness. Coliform bacteria themselves aren’t always dangerous, but they’re a strong indicator that cleaning standards have slipped.


The PFAS Angle


PFAS exposure isn’t about getting sick tomorrow. It’s about long-term accumulation. Fountain drinks aren’t likely to be your biggest PFAS source, but if you’re drinking them regularly, they may contribute to your overall exposure.

And with PFAS, the dose adds up.


How to Lower Your Risk (without spiraling)


If you run or manage a food service business:


  • Fully disassemble & sanitize nozzles & valves on a regular schedule

  • Clean internal lines, not just visible surfaces

  • Flush machines after downtime

  • Replace filters when you’re supposed to (not when it’s convenient)

  • Test source water in PFAS-affected areas

  • Consider advanced filtration like activated carbon or reverse osmosis


If you’re just trying to get a drink:


  • Avoid machines with visible grime, mold, or sticky buildup

  • Let the drink run briefly before filling your cup

  • Choose busy locations, high turnover usually means more frequent cleaning

  • When in doubt, grab a canned or bottled drink

  • Reduce overall PFAS exposure by using filtered water at home


No panic required. Just awareness.


Where This is Headed


  • The EPA has rolled out stricter PFAS limits for drinking water

  • The FDA continues testing foods & beverages for chemical contamination

  • Public health experts are calling for better sanitation oversight of beverage dispensers

  • Research on biofilms in food service equipment is ongoing


Translation: soda fountains aren’t going unexamined anymore.


The Takeaway


Fountain drinks aren’t automatically gross, but they’re also not as clean as we like to believe. Bacterial contamination is a known issue when maintenance falls short, and PFAS remain a broader environmental concern that can travel through water systems and equipment.


The solution isn’t quitting soda forever. It’s better standards, better filtration, and better information. Once you know what’s going on behind that button, you can make smarter choices, no fear required.


Sources


 
 
bottom of page