Why is my toilet seat turning blue

Why Is Your Toilet Seat Turning Blue? [Reasons + Cleaning Ideas]

Why is my toilet seat turning blue

So it’s a sweet early morning and you stumble into the bathroom just to get surprised with a blue butt and thighs imprint on the toilet’s seat?

Possibly, your first reaction would be to blame the other members of the house who share the same bathroom. After all, you didn’t dip your butt in blue ink and then smeared it all over your snow-white seat! Of course, to be 100% guaranteed you’re not the culprit, you’ll look in the mirror and would definitely find that your trusty a** is the same color it’s always been.

And then after that uncomfortable investigation with your bathroom partner, when they swear by not discoloring your hard or soft plastic toilet seat, you will find yourself buckled under the strain… thinking of what actually caused your toilet seat to turn blue, black, or light grey?

Why Is My Toilet Seat Turning Blue? [Explained]

There are different reasons behind the toilet seat’s discoloration into blue.

As per theories, it is due to the reaction of the chemicals excreted through a person’s sweat and the toilet seat’s components. Sweat-glands-disorder called Chromhidrosis, that causes blue colored sweating. Corynebacterium (present on human skin) reacting with the silver coating on the cover. A dye from medication or a supplement that might be leaching out in the person’s sweat. Or simply the dye of your blue jeans that have rubbed against your skin and then transferred to the toilet seat.

Let’s dig deeper into the details and learn what causes blue tinges on the seat of your bathroom.

Also Read: Why Is My Toilet Seat Turning Pink or Purple?

1). Your hormones are likely to be blamed.

Toilet Seat Turning Blue reason

A majority of men and women who reported the blue seat phenomenon had one thing in common and that was “imbalanced hormone levels”. Hormonal changes before, during, and after pregnancy can cause temporary pseudochromhidrosis. This state temporarily creates a rare sweat condition that interacts with some surface bacteria, and blue/black staining is the consequence on certain surfaces such as the toilet seat.

Are you a male or not a pregnant lady… but still caused the toilet seats to turn a shade of blue?

Here again hormone levels that are out of balance are guilty of wreaking havoc on your bathroom’s toilet seats.

So it’s just the reaction between the chemicals excreted through your skin during the hormonal imbalance stage and the components of the toilet seat. However, not all toilet seats respond to this reaction. For example, some people have reported that it only happened to their white soft toilet seat and that the use of a hard toilet seat did not cause the same reaction.

2). You have acidic skin.

Are you on to some sort of medication or vitamin dose? Medicines, especially those taken during pregnancy or energy supplements rich in Vitamin B complex imbalance the natural acidity of the human body. Not everyone’s body reacts to medication intake like this, but some do.

These chances are even higher when you are pregnant. As medicines in pregnancy combined with the elevated levels of Estrogen and Progesterone are enough to change your body’s chemistry.

The change in the PH of the skin (i.e skin turning acidic) causes an instant reaction when sweat excreted through your acidic skin reacts with the toilet seat’s surface. The difference in the pH of the skin reacts with the ionized silver antimicrobial coating of the toilet seats which causes the silver to oxidize and take on a blue hue. As a result of this sweat-surface reaction, blue stains form all over the toilet’s surface where your sweaty butt and thighs have come into contact against.

Not sure about your body’s PH? Take acid testing strips from a local drug store and monitor your body’s PH level using your saliva or urine – early in the morning on an empty stomach or as instructed on the strip.

3). Sweat glands or skin disorders.

Photo Source: Medical Journals

Disorders like Corynebacterium and Chromhidrosis are other reasons behind your toilet seat turning blue.


Corynebacterium is present in human skin. All species of this bacteria require Vitamin B7 (Biotin), Vitamin B1 (Thiamin), Para-Aminobenzoic Acid PABA (an amino acid generally present in folic acid supplements/vitamins), and Prenatal vitamins to grow.

And aren’t most of us taking these supplements particularly for hair, nails, and skincare?

This bacteria allows your sweat/body oils to have a blue / greyish hue that can be transferred. It might also react with antimicrobial coatings on things like toilet seats.


Chromhidrosis is a sweat gland disorder that causes yellow, blue, black, and green sweat excretion in humans. These colors are caused by a pigment called lipofuscin, which is formed in the sweat glands. Lipofuscin is normal in human cells, but people with chromhidrosis have elevated amounts of lipofuscin, which triggers discoloration of body oils.

People suffering from any of these disorders would also probably have blue stains on their shirt’s armpit areas, bedsheets, underwear, and forehead.

4). Your jeans or underwear dye rubbing off on your skin and transferring to the toilet seat.

jeans pants toilet seat

The indigo dye on your new jeans or dark-colored underwear might have rubbed everywhere on your skin, and that color could have immediately transferred to the toilet seat as you sit down to do your thing. So look for colorfastness in your clothes before thinking there’s an odd chemical reaction taking place inside your skin or body.

5). You are Covid positive.

We recently learned, thanks to honest comments from a large number of victims, that Covid positive patients are often vulnerable to turning their toilet seats blue or purple. Therefore, aside from the more common symptoms such as fever, dry cough, and tiredness, the blue coloration of the toilet seat is another addition to the symptoms chart.

Laura Clabeaux, one of our readers who contracted coronavirus back in November, says:

“I tested positive for COVID in November and that’s when my seat started to turn blue/ purple. I was wondering if anyone else who is not pregnant and had COVID if this happened to them. It’s just weird that this happened out of nowhere.”

Another reader, Debbie Hartwell says that it happened after receiving Pfizer vaccines:

“I never had COVID, but I received both Pfizer vaccines and after the second, two days later my toilet seat turned blue/purple. Strangest thing!”

How To Get Rid Of Blue Stains From Toilet Seat?

Here’s what you can do to clear blue stains from your toilet seat:

  • Get a high-quality toilet bowl cleaner or a bleach cleaner. Normal household bleach will fit well, too.
  • Squirt the solvent onto the stained surfaces.
  • Let the solvent rest for a few minutes to fight off the blue tint and disinfect bacteria.
  • Use a gentle brush to clean the dyed surface.
  • Avoid exerting too much pressure or using rough brushes, since they may scrape the toilet seat and remove the protective lining of the toilet.

Also, try a quick dab of a nail polish remover on a cotton ball, if nothing else eliminates the blue stain from the plastic. Try at a discreet place first just to ensure there is no unusual reaction. A huge amount can harm the toilet’s finish, so just use a small amount and see. Nail polish remover has saved many people the cost of purchasing a new toilet!

Can I Remove The Blue Stain Completely?

Yes, if it is just a dye from your jeans. Very difficult or impossible if it has occurred due to a chemical reaction between your body’s oils and the toilet seat’s surface.

People tried Magic Erasers, alcohol, vinegar, ammonia, and more, with no luck. Since the blue hue is probably due to a chemical reaction (rather than a stain), there is no turning back. You can lighten the tint, however, the only way to get your seat white again is to buy a new one.


There are several theories behind the toilet seat turning blue. The most common one is the reaction of sweat/body oils excreted through your hormonally-imbalanced or acidic body with the toilet seat’s surface. A condition like Corynebacterium and Chromhidrosis could also be the reasons. If not anything, it’s probably a dye transfer from your jeans.

7 Replies to “Why Is Your Toilet Seat Turning Blue? [Reasons + Cleaning Ideas]”

  1. I tested positive for COVID in November and that’s when my seat started to turn blue/ purple. I was wondering if anyone else who is not pregnant and had COVID if this happened to them. It’s just weird that this happened out of nowhere.

    1. Oh, Hope this message finds you in good health. Thanks for sharing your insight with us. It’s surely a very strange thing!

    2. I never had COVID, but I received both Pfizer vaccines and after the second, two days later my toilet seat turned blue/purple. Strangest thing!

  2. This has happened to me numerous times, typically with the wood/painted toilet seats. You NEVER have to replace the toilet, just the toilet seat. $25 or less! I’ve started using a plastic seat and so far so good.

  3. We have been desperately trying to figure out why one toilet seat turned blue, but not the other. It is only ever used by my daughters (8 & 12 yrs old) neither of which are pregnant, ever had COVID or received vaccines, and no one leaves blue sweat stains on any clothes. I’m thinking it’s my 12 year old’s crazy pubescent hormones?? Going to pick up a PH test later! I gotta figure this out!!

Leave a Reply

Your email address will not be published. Required fields are marked *