Your Phone Screen Has More Germs Than a Public Toilet Seat

Your Phone Is Filthy. Here Is the Proof.

In 2012, researchers at the University of Arizona found that cell phones carry 10 times more bacteria than most toilet seats. A 2017 study published in Germs confirmed similar numbers, identifying bacteria on 100 percent of phones tested, with an average of 17,032 bacterial gene copies per phone.

Insurance2Go, a UK phone insurance company, commissioned lab testing of smartphones in 2018 and found that the average phone screen had 84,672 colony-forming units of bacteria. The home button area was even dirtier. The back of the phone case was the worst of all.

For context, a typical toilet seat has around 50 colony-forming units per square inch. Your phone is not just a little dirtier than a toilet. It is in a completely different league.

And unlike a toilet seat, you press your phone against your face.

Why Phones Are Perfect for Bacteria

A toilet seat is actually a poor habitat for bacteria. It is a cold, dry, hard surface that gets cleaned (at least occasionally) with disinfectants. Bacteria land on it, and most die relatively quickly.

Your phone, on the other hand, offers bacteria an environment they love:

Warmth. Your phone generates its own heat from the processor and battery, and it spends most of its life either in your warm hand or your warm pocket. Bacteria thrive at body temperature.

Constant contact with skin. Every time you touch your phone, you transfer bacteria from your fingers. The average person touches their phone 2,617 times per day, according to a 2016 study by Dscout. Heavy users touch theirs over 5,000 times daily. Each touch deposits oils, dead skin cells, and the microorganisms that live on your skin.

It goes everywhere. Your phone accompanies you to the kitchen, the bathroom, the gym, public transport, restaurants, and your bed. A 2019 survey found that 75 percent of Americans admit to using their phone on the toilet. Every surface your phone touches becomes a transfer point for microorganisms.

It almost never gets cleaned. A survey by Deloitte found that while people clean their homes, their cars, and even their computer keyboards, fewer than one in three people regularly clean their phone screens. Most phones have never been deliberately disinfected.

What Is Living on Your Phone

The bacterial communities on phones closely mirror what lives on their owners' hands and faces. Common residents include:

• Staphylococcus aureus -- Found on roughly 20-30% of phones tested in various studies. While many staph strains are harmless skin commensals, S. aureus can cause skin infections, and MRSA (methicillin-resistant S. aureus) has been detected on phones in hospital settings.
• Streptococcus -- Common skin and throat bacteria. Usually harmless but responsible for strep throat and some skin infections.
• E. coli -- Found in a disturbingly high percentage of phone studies. Its presence on your phone strongly suggests fecal contamination -- likely from using the phone in the bathroom without washing hands afterward.
• Corynebacterium -- A skin commensal that is among the most abundant bacteria on phones. Generally harmless.

A 2020 study from the Journal of Travel Medicine also detected viable SARS-CoV-2 on phone screens, leading some public health researchers to suggest that phones could serve as fomites (surfaces that transmit infection) during respiratory illness outbreaks.

It is worth noting that most of the bacteria on your phone are your bacteria. They are part of your normal microbiome and are unlikely to make you sick. The risk increases when you share phones with others, when you use your phone in hospitals or other high-risk environments, or when you touch your phone after handling raw food and then touch your face.

How to Actually Clean Your Phone

Apple, Samsung, and Google all now officially endorse cleaning phone screens with 70% isopropyl alcohol wipes. This was not always the case -- manufacturers used to warn against alcohol for fear of damaging oleophobic (fingerprint-resistant) coatings. But during the COVID-19 pandemic, most revised their guidance.

Here is a practical cleaning routine:

1. Daily wipe-down. Use a microfiber cloth slightly dampened with 70% isopropyl alcohol. Wipe the entire phone -- screen, back, sides, and especially around the camera bump and charging port area. Let it air dry.
2. Do not use these: household glass cleaners, kitchen sprays, hand sanitizer (the additives can damage coatings), compressed air in the charging port, or anything abrasive.
3. UV sanitizers work but are not necessary. Products like PhoneSoap use UV-C light to kill bacteria and do reduce microbial counts. But a simple alcohol wipe achieves similar results at a fraction of the cost.
4. Clean your phone case too. If you use a case, remove it weekly and clean both the case and the back of the phone. The gap between phone and case traps moisture and debris -- bacteria love it.

The Touch-Your-Face Problem

The phone-to-face pipeline is what makes phone bacteria more concerning than, say, doorknob bacteria. You do not press doorknobs against your cheek and mouth.

The average person touches their face 23 times per hour, according to a 2015 study in the American Journal of Infection Control. Many of those touches come immediately after handling a phone. This creates an efficient transfer route for bacteria and viruses from contaminated surfaces to mucous membranes (eyes, nose, mouth) -- the primary entry points for respiratory and gastrointestinal infections.

Dermatologists have even coined the term "acne mechanica" for breakouts along the cheek and jawline caused by pressing bacteria-laden phones against the skin. If you are battling persistent breakouts on one side of your face, your phone might be a contributing factor.

Perspective and Practical Takeaways

Let's be clear: your phone is not going to kill you. Most of the bacteria on it are harmless inhabitants of your own skin. The "dirtier than a toilet" comparison, while factually accurate in terms of raw bacterial counts, is somewhat misleading because toilet seats are unusually clean surfaces, not because phones are unusually dangerous ones.

That said, the sheer volume of bacteria on an object you press against your face dozens of times a day is worth addressing -- especially during cold and flu season, or if you have a habit of using your phone while cooking. A 30-second daily wipe-down is a trivially easy habit that makes a measurable difference.

Your phone is the most-touched object in your life. Treat it accordingly.

Related: Your Kitchen Sponge Is Dirtier Than Your Toilet · WiFi Routers Emit Less Radiation Than a Baby Monitor · There Are More Bacteria in Your Mouth Than People on Earth