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Chemical Drain Cleaners

Chemical drain cleaners are a go-to solution for many homeowners with blocked or slow drains. If used correctly, they are great for clearing many types of clogs. But if used improperly, they can damage plumbing and septic systems and be harmful to your health. Before you pour, be sure you have chosen the right one for your home and the type of clog you are trying to clear.

Types of Chemical Drain Cleaners

There are three common types of chemical drain cleaners; oxidizing, caustic, and acid. Oxidizing and caustic cleaners are the most common type and they are widely available in stores across America. Many household clog removers contain both oxidizing and caustic compounds. Acid drain openers are professional products that are only available to licensed plumbers. Each has advantages and disadvantages. All drain cleaners are safe if used properly and potentially harmful if used incorrectly.


Oxidizing drain cleaners contain peroxides, household bleach, or nitrates. They clear drains by oxidizing organic materials. Oxidizing compounds are very reactive. They steal electrons from other substances, which breaks them down and produces heat and gas. It’s the same reaction responsible for the fizz when hydrogen peroxide is applied to a cut, or the color fading caused by bleach.

Just like when bleaching a t-shirt, the strength of the reaction depends on the amount of oxidizer present, the ambient heat, and the length of time it’s applied. Household bleach and the hydrogen peroxide found at the grocery store are relatively weak compounds, as are many drain cleaners. For instance, regular bleach contains about 5.25 percent sodium hypochlorite (household bleach) and Liquid Plumr Industrial Strength Clog Remover contains between 3 and 7 percent household bleach and less than 2.5 percent sodium hydroxide (lye). Some specialty products also contain myristamine oxide, which is also used to stabilize foam in shampoo or lauramine oxide, which is a mild surfactant commonly used as a foam booster or cleansing agent.

Oxidizing drain cleaners are great at removing basic food-based blockages, and they are heavy enough to sink through standing water. The heat and gas also help to loosen hair clogs and dissolve soap scum. Since they aren’t much more concentrated than typical household products, they are safe if used correctly.


Caustic drain cleaners contain caustic substances such as sodium hydroxide (lye or potash). They’re bases that give electrons away, which can make soaps and grease dissolve easier. Caustic compounds such as lye are common in many grease-cutting household products and scouring products, including drain cleaners and oven cleaner. Lye is also used to make soaps, and to cure and tenderize foods.

Caustic substances are good at breaking up greasy and soapy clogs. They can move through standing water to get down to the clog. They also produce heat and gas, which helps clear the blockage. In high concentrations, they are quite strong. Concentrated bases are just as reactive as concentrated acids, but many household drain cleaners only contain small amounts of it, so they are safe if properly used. For example, Drano Max Professional Strength Gel Clog Remover contains less than 5 percent lye and between 3 and 10 percent household bleach.


Acid drain cleaners are strong substances that are only sold to licensed plumbers. They contain high concentrations of hydrochloric or sulfuric acid, which attract electrons to break up substances. Their use is restricted for good reason. They are very strong and can dissolve organic substances like food, grease and hair or inorganic substances like plastic, metal, and ceramic.

How to Use Chemical Drain Cleaners Safely

Like any household cleaner, chemical drain cleaners can be harmful if used incorrectly. They can damage metal and PVC pipes, or break down rubber pipe fittings if they are used too often or for too long. They can also harm beneficial bacteria present in septic systems. They are poisonous if ingested and can burn the skin, mucous membranes, and eyes. They can also react with other common household cleaners and produce noxious fumes.

When choosing a chemical drain cleaner, read the label carefully to be sure it is safe for your plumbing. Also, be sure to follow all the safety precautions included with the product. Wear protective gloves and eyewear and long sleeves. Do not pour them down the drain if you have recently used another type of clog remover or another household cleaner such as ammonia. Also, be sure to keep children and pets away while you are using them, and store them safely out of reach.