I Tested Sodium Percarbonate on a Stubborn Nosebleed Stain — It Actually Disappeared! (The Science of Cleaning)
I’m Ken Kuwako, your Science Trainer. Every day is an experiment!
When your child gets a nosebleed, those bloodstains can be surprisingly stubborn. Even after washing, they often refuse to disappear. So this time, I decided to put sodium percarbonate to the test and see whether this powder could really get rid of those stubborn nosebleed stains!
Sodium percarbonate (Amazon)
I prepared some lukewarm water at around 50°C in a basin and added an appropriate amount of sodium percarbonate. Then I soaked the stained cloth for about an hour. The result? The stain was already much less noticeable.
I thought, “I wonder if I can get it even cleaner?” So I left the cloth soaking for a full day. The stain faded until it was barely visible, and the effect was pretty impressive.
Here’s a comparison…
And here’s a closer look…
Sodium percarbonate is useful for much more than stain removal. It can also be used to sanitize laundry, clean washing machines, and wash bathwater heaters and other bath accessories. It’s a remarkably handy cleaning powder!
What exactly is sodium percarbonate?
The name “sodium percarbonate” may be new to some of you. In Japanese, it is pronounced “katan-san.” In English, it is called “sodium percarbonate.” Its formal chemical name is sodium carbonate hydrogen peroxide (wikipedia).
Its chemical formula is 2Na₂CO₃・3H₂O₂, which looks a little intimidating. It consists of:
- Sodium carbonate (Na₂CO₃): A powder related to baking soda that is also commonly used for cleaning.
- Hydrogen peroxide (H₂O₂): The active ingredient found in antiseptic solutions such as Oxydol. It is also used in the classic “elephant toothpaste” experiment and can be hazardous at high concentrations.
These two substances are essentially joined together to form a single powder. When different substances are combined in this way while retaining their original identities, the resulting material is called an “addition compound.” When sodium percarbonate dissolves in water, this combination comes apart, releasing the original sodium carbonate and hydrogen peroxide.
Hydrogen peroxide is the real bleaching star!
You could think of sodium percarbonate as a kind of “powdered hydrogen peroxide.” That is why it is the main ingredient in oxygen-based bleaches such as OxiClean.
Hydrogen peroxide eventually breaks down into water and oxygen. The oxygen bubbles produced during this process help loosen dirt from the fibers, while the oxidation reaction bleaches the stain.
I also recorded the bubbles being produced in a video. Yep, those are oxygen bubbles!
By the way, hydrogen peroxide decomposes faster as the water gets warmer. Soaking the fabric in water at around 40–50°C produces more bubbles and speeds up the reaction, which can boost both cleaning and bleaching performance.
There’s another important factor, too. As hydrogen peroxide breaks down, it exerts a strong oxidizing effect. This oxidation damages the molecular structures responsible for the color of the stain, causing that color to disappear.
The alkalinity of sodium carbonate also plays an important role!
Blood contains a lot of protein. When sodium percarbonate dissolves in water, the solution becomes mildly alkaline, thanks to the sodium carbonate. This alkalinity helps cause proteins to swell, a process called “swelling” or “swellability.”
Swelling simply means that something absorbs water and expands. When proteins absorb water and swell, the dirt stuck to the fibers becomes loosened and is more easily lifted away. In other words, two cleaning effects work together: the alkalinity loosens the stain, while the oxidizing power breaks down its color. That combination is what makes even stubborn bloodstains much easier to remove.
When people hear “alkaline,” many of us immediately think of baking soda. Alkaline substances can help remove stains in several ways:
- Grease and body oils → They help break them down by converting them into soap-like substances.
- Protein stains (blood, sweat, etc.) → They cause the proteins to swell, helping lift them away from the fibers.
Sodium percarbonate is sold as a powder on its own, but it is also included as an ingredient in a variety of cleaning products. So the next time you’re struggling with a stubborn stain, why not give it a try?
Sodium percarbonate (Amazon)
＜References＞
Sekken Hyakka (Soap Encyclopedia)
・What is sodium percarbonate (oxygen-based bleach)?
・pH and the bleaching effect of sodium percarbonate (oxygen-based bleach)
wikipedia Sodium carbonate hydrogen peroxide
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