Is It Bad to Pour Soda Down the Drain?

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Using Coca-Cola for clogged drains is only one of the uses that people have found for this beverage. Rumor has it that highway patrol officers keep it in the trunk to clean the road after an accident. Whether that is true or not, many people use Coke to clean the battery terminals in their cars.


So, is it bad to pour soda down the drain? Though Coke can clear a clogged drain, it takes awhile, can leave behind residue, and there are other household items that are better suited for this task.

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Ingredients in Coca-Cola

The complete list of ingredients in Coca-Cola is a closely-guarded secret, but the label lists carbonated water, caramel, cane sugar, flavor, caffeine and phosphoric acid. The latter is added to give the drink a tangy flavor. It is a mildly corrosive acid used primarily in the manufacture of fertilizer and detergents.


Among the industrial uses of phosphoric acid are cleaning rust off metal in preparation for painting. Phosphoric acid is a corrosive material that's very hazardous if ingested. Ingestion can lead to severe burns in the gastrointestinal tract. The concentrations in Coke, however, are too small to be harmful.

Coca-Cola for Clogged Drains

Most over-the-counter drain cleaners, unless they are enzyme-based, contain sodium hydroxide, also known as caustic soda. It works by increasing the alkalinity of the water in the drain until it is high enough to dissolve clogs. Stronger drain cleaners for professional use, on the other hand, usually contain sulfuric acid, which raises the pH in the opposite direction.


The phosphoric acid in Coke works in the same way as sulfuric acid but not as quickly. It is a weaker acid and present in a much smaller concentration in Coke than sulfuric acid in drain cleaner. Consequently, if you use Coca-Cola for clogged drains you have to leave it in the drains longer.

How to Clean Your Drain With Coke

Coke is really only effective if your drain is completely clogged because it needs a long time to work. If you pour it into a partially clogged drain, it will just pass through without any noticeable effect. The drain should also ideally be free of standing water that will dilute the Coke.


  1. If your clog meets these conditions, here's how to clean your drain with Coke:
  2. Pour an entire 2-liter bottle down the drain and let it work overnight.
  3. Check the drain in the morning, and if the clog has cleared and there is no more Coke, flush it with hot water.


You can even use Coke to unclog toilets and not just sink or shower drains.

Drain-Cleaning Alternatives to Coca-Cola

You have more effective ways than using Coke to unclog shower drains or other household drains. If you don't want to use a commercial drain cleaner out of concern for your pipes and its potential adverse effects on the environment, you can reach for the baking soda and peroxide. Baking soda is mildly alkaline and will deodorize as it cleans while the foaming action of peroxide will loosen debris.


It's recommended to pour 1 cup baking soda down the drain and let it settle for 10 minutes. Pour 1 cup hydrogen peroxide down the drain to create a foamy cleaner. After several hours, pour hot water down the drain.



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