It seems obvious: you flush and the paper disappears. But does toilet paper dissolve in water? And if it does, why does the toilet still clog sometimes? The short answer: yes, toilet paper breaks apart in water, usually within a few minutes once the water is moving. It just doesn't truly dissolve the way sugar does. In this article you'll learn how it works, how long it takes, why tissues and paper towels don't break apart, and how to test in half a minute whether your toilet paper breaks down properly.
Does toilet paper dissolve in water?
Yes and no. Toilet paper doesn't dissolve like sugar or salt, where the material disappears into the water. What actually happens is called disintegration: the fibers that make up the sheet let go of each other, and the sheet turns into a slurry of loose fibers that flows easily with the water. Those fibers themselves (cellulose) are only broken down later by bacteria, at the wastewater treatment plant or in a septic tank. That takes weeks.
For your plumbing, that distinction doesn't really matter. What counts is that the sheet breaks apart quickly enough to pass through the pipes without any trouble.
Why does toilet paper break apart but a tissue doesn't?
A sheet of paper is a network of cellulose fibers held together by what are called hydrogen bonds. Water breaks those bonds: the fibers swell and slide apart. With toilet paper, that's exactly the point. It's strong enough to use when dry, but quickly loses its structure in water.
Tissues, paper towels and napkins, on the other hand, are made to stay strong when wet. To do that, they get wet-strength agents: additives that bind the fibers together more tightly. Handy when you're mopping up a spilled glass of milk, a disaster in the toilet. Wet wipes go one step further: they often contain plastic fibers and barely break apart at all.
How long does it take for toilet paper to dissolve?
Good toilet paper starts breaking apart within seconds to minutes once it lands in moving water, like when you flush. According to plumbing company Roto-Rooter, breaking down completely can take anywhere from a few hours to a couple of days, depending on the type of paper and the amount. In still water it goes more slowly than in a flowing sewer pipe.
Exactly how fast it goes depends on:
- The number of plies and thickness: a thick 4-ply sheet contains more paper and needs more time than a thin 2-ply sheet. More on that in 3-ply toilet paper vs 2-ply and 4-ply.
- Additives: lotion, balm and wet-strength agents slow down the breakdown.
- Movement: flushing and flowing water speed up the process considerably.
- Amount: flushing half a roll in one go is asking for trouble, even with good paper.
- Water temperature: warm water helps a little, cold water slows it down slightly.
What breaks apart in water and what doesn't?
| Product | Breaks apart in water? | Down the toilet? |
|---|---|---|
| Toilet paper | Yes, within minutes | Yes |
| Pocket tissues and facial tissues | No, they're made to be wet-strong | No |
| Paper towels | No, also wet-strong | No |
| Wet wipes, including "flushable" ones | Barely | No |
| Cotton pads, sanitary pads, tampons | No | No |
In practice, it's mainly wet wipes that cause blockages in homes and sewage pumping stations. Find out why "flushable" on the pack doesn't mean much in can you flush wet wipes down the toilet? And paper towels belong in the trash after use, however sustainable they are; see also bamboo paper towels.
Test it yourself: does your toilet paper dissolve properly?
- Fill a glass jar three-quarters full with room-temperature water.
- Add a few sheets of toilet paper and screw the lid on.
- Shake firmly for a few seconds and wait 30 seconds.
- Does the paper break apart into small pieces and loose fibers? Then it's fine. Is it still floating around as one sheet? Then it breaks apart slowly.
Try the same test with a tissue or a sheet of paper towel: you'll see the difference right away. Have a septic tank or a camper? Then also read which toilet paper is safe for a septic tank.
What happens to toilet paper after you flush?
Through the sewer, the paper ends up at the wastewater treatment plant. There, most of the fibers are screened out of the water and processed. In the Netherlands, some water boards go a step further: in pilots with Cellvation technology, including at the Geestmerambacht wastewater treatment plant near Alkmaar, cellulose from toilet paper was recovered and reused, for example in asphalt for bike paths.
If you have a septic tank, bacteria in the tank do the work. That's where it's extra important that paper breaks apart quickly and contains no lotion or fragrance, because whatever doesn't break down sinks to the bottom as sludge.
What dissolves toilet paper in a clogged toilet?
If your toilet is blocked by too much paper, the fix is usually simple: time, hot (not boiling) water and maybe a squirt of dish soap. Let it soak for a while, then use a plunger. Harsh chemical drain cleaners are rarely needed for a wad of paper and are bad for your pipes. Read the full step-by-step guide in toilet clogged by toilet paper? Here's how to fix it.
Does bamboo toilet paper dissolve well?
Yes. Bamboo toilet paper is made from cellulose fibers, just like regular toilet paper, and breaks apart in water the same way. Bamboi's bamboo toilet paper contains no lotion, fragrance, dyes or added softeners that slow down the breakdown. That makes it suitable for regular sewer systems and for septic tanks. When dry, the 3-ply sheet is soft and strong. Want to know more about bamboo and the environment? Read biodegradable toilet paper.
Frequently asked questions about toilet paper dissolving
How long does it take for toilet paper to dissolve in water?
In moving water, good toilet paper starts breaking apart within seconds to minutes. Breaking down completely can take a few hours to a couple of days, depending on the paper and the amount. After that, bacteria break the fibers down further over the course of weeks.
Does toilet paper dissolve in hot water?
Hot water helps a little, but the difference compared with cold water is small. If you have a clog, though, hot (not boiling) water is handy for softening a wad of paper. Boiling water can crack a porcelain toilet bowl.
Does 3-ply toilet paper dissolve more slowly than 2-ply?
A thicker sheet needs a little more time, but the difference is small as long as the paper contains no wet-strength agents or lotion. Additives matter more than the number of plies.
Can you flush tissues down the toilet?
No. Pocket tissues, facial tissues and paper towels are made to stay strong when wet and barely break apart in water, if at all. Throw them in the trash.
Does toilet paper dissolve in a septic tank?
Yes, but more slowly than in the sewer, because there's little flow. Bacteria in the tank break down the fibers. That's why it's best to choose paper that breaks apart quickly and contains no lotion or fragrance.
Conclusion
Toilet paper doesn't dissolve like sugar, but in moving water it breaks apart into loose fibers within a few minutes. Tissues, paper towels and wet wipes don't, which is why they never belong in the toilet. Choose paper without lotion or fragrance, don't flush too much at once and your drains will stay clear. Check out the bamboo toilet paper from Bamboi®.
