Drain lines are prone to clogs from time to time. They mostly clog due to pouring the wrong things down the sink such as solid waste and cooking oil. The sink drain is highly prone to clogging due to pouring food leftovers and oils down the sink.

There are different ways of clearing clogged sink drains. One of the most commonly used methods for clearing clogs is pouring boiling water into the sink. Most sink drains are made of PVC pipes whose melting point is 80 degrees Celcius.

drain cleaner for pvc pipes


Thus, boiling water can soften PVC pipes. If the water is under pressure, the boiling point of PVC pipes goes down to just 140 degrees Fahrenheit.

Besides boiling water, there’re certain chemical components in drain cleaners that can soften or melt PVC pipes.



There are many drain cleaners available in the market today. The drain cleaners that soften PVC pipes are oxidizers, caustics, and acids. Acid cleaners have either hydrochloric acid or sulfuric acid as their active ingredients.

Oxidizers have sodium hypochlorite as their active ingredient whereas caustic cleaners come with sodium hydroxide as their active ingredient. Sodium hydroxide is also referred to as lye.


Generating Heat

Chemical reactions that result from sodium hydroxide, sulfuric acid, and hydrochloric acid generate a lot of heat. For instance, sodium hydroxide generates excessive heat that raises the temperature beyond the PVC pipes’ boiling point.

While these chemicals are caustic by nature, it’s the kind of heat they generate from their chemical reactions that make PVC pipes soften and eventually melt.

The chemical reaction worsens when using multiple chemicals to clean the drain. For instance, if you mix acidic and caustic drain cleaner, the resulting chemical reaction will be stronger than when using only one chemical.

The reaction resulting from using multiple chemicals generates excessive heat to the extent of the chemical erupting from the drain. Hydrochloric acid and sulfuric acid react excessively with water when mixed together.

The chemical reaction is excessive such that even attempting to dilute these chemicals with water would lead to more problems. Adding water will thereby generate more heat and damage the PVC pipes.


Oxidizing Agents

Sodium hypochlorite, also known as chlorine bleach, isn’t known to melt PVC pipes. However, some oxidizers are usually added to some caustic chemicals to enhance their effectiveness in cleaning drains.

However, once the materials blocking the drain mix with the oxidizers, a chemical reaction occurs that generates a lot of heat. Lye in its granular form contains particles of aluminum.

They generate excessive heat upon reacting with water, leading to the generation of hydrogen gas. Consequently, you’ll have more problems to deal with when using PVC pipes due to the additional heat.


The Safest Options

Enzymatic drain cleaning agents work by using living organisms that eat the clog materials blocking the drain.

Although these drain cleaners work a bit slower than those made of chemicals, they are designed to feed on organic matter and don’t generate heat. Moreover, they’re noncorrosive.

The shelf-life of enzymatic based drain cleaning agents is very short. Drains can also be cleaned using mechanical methods such as using an auger (plumber’s snake) or a plunger.


Related Articles:

How Can Clay And Dirt Dissolve In Clogged Drain Pipes?

Plumbing Pipes: The 7 Main Types of Pipes You May Encounter

The Differences between Type L and Type M Copper Pipes

What’s The Best PVC Pipe for Underground Usage?

A Guide for Bending PVC When Making a Circle