Will Bleach Unblock a Kitchen Sink?

You’ve got a kitchen sink clog, and you may have heard THAT bleach works to dissolve the gunk. Bleach is a common multipurpose household item widely used for laundry, disinfection, deodorizing and various cleaning jobs, and has been with us in some form since shortly after the American Revolutionary War. Chlorine-based bleach (sodium hypochlorite like Clorox®) is the current formula commonly found in the household.

But the question is really threefold: 

  • Is bleach effective at unblocking a kitchen sink?
  • Is it safe?
  • Is there a better way to clear the clog?

The last thing we want to occur is to create the need for a kitchen sink repair or an even deeper plumbing repair due to using the wrong method to loosen and clear a clog. You must consider if pouring bleach down the drain will damage the pipes or stress the joints — we will cover those questions a little further on.

Is Bleach Effective for Clogs?

Let’s get one thing out of the way. If you have a septic system, never pour bleach down your drains. It will kill the beneficial bacteria your septic tank needs to break down the septic waste from solid into liquid. If you do pour bleach down your drain, you may produce a massive clog and permanent damage to your septic system.

If you read on the internet that bleach is good for clogs, you will discover both yes and no answers. Bleach can dissolve hair caught in tub drains and bathroom sinks and that may be why some people believe it is an effective fix. If the hair has been accumulating in the drain for even a short while, it has gathered soap scum and other debris and is now largely protected from being dissolved by bleach. Non-chlorine or oxygen bleaches are designed to be gentle on clothing and dyes and with reduced ability to dissolve hair. 

The bottom line is that bleach alone is not very effective in unclogging drains. It can sanitize, or even knock off some debris from the walls of the drain. You may see bleaching compounds in the list of ingredients on the label of a drain cleaner, but this bleach is used in combination with other drain cleaning elements. The bleach in these products is not what unclogs the drain.

Is Bleach Safe To Pour Down the Sink?

We live in a chemical world. All organic matter changes form and structure through chemical reactions. Bleach is a powerful chemical agent and very toxic. If inhaled, its fumes can cause damage to your lungs and other organs. Chlorine-based bleach can damage skin and eyes, sometimes permanently. Bleach in concentration can also cause nerve damage. 

No one really knows, moment to moment, what is already down their kitchen sink drain when they pour bleach in it. Bleach and cleaning fluids can create toxic gases when mixed together and contaminate the air in your home. Chloroform is created by mixing bleach with rubbing alcohol or acetone (acetone is commonly found in liquid and paste waxes, nail polish remover, baby wipes, many skin lotions, etc.). If bleach is mixed with ammonia it can form a deadly gas that can significantly impact lung function. 

Some other things that bleach should never be mixed with:

  • Vinegar
  • Dish soap
  • Drain cleaners
  • Any cleaning product containing acids or ammonia (forms chlorine gas). 

Remember that children, pets and birds can be much more sensitive to off-gas chemical reactions than adults. 

When you pour bleach down the kitchen sink, you are, in effect, loading a tube (the drain piping) that is sometimes subject to reverse air pressure – a situation that could cause what is in the pipe to come back up and splash in your face or get into your kitchen and on your tableware. 

Can I Pour Bleach Down the Drain?

Bleach is not always safe for the environment beyond your drains either. While it is true that it eventually breaks down in the sewer system, a single ounce of bleach requires 312,000 ounces of water to be safe for fish. Even if you are pouring bleach down your sink to get rid of it, it should be done incrementally, using plenty of water.

Bleach reactions with the random chemicals in a clog may generate enough heat to compromise the drain pipes or their joints. Kitchen drain pipe ruptures may occur much farther down the line than what’s inside your kitchen cabinet. When they do, you could have sewage leaks inside the walls that aren’t immediately noticed until untold damage has occurred.

What You CAN Do to Unclog a Kitchen Sink

Kitchen sinks are generally easy enough to clean without having to resort to heavy chemicals. You know what your family generally uses the kitchen sink for, so you can guess that the clog involves fibrous food particles, grease, possibly napkins, foods that expand in water even after they are cooked like rice and pasta, and so on.

  • If both sides of your sink are filling up with water, firmly stopper the non-disposal drain and turn on the disposal while running hot water down the drain. Very often the pressure on the line will cause the clog to blow through. 
  • Use a plunger. Fill the sink with enough standing water to cover the bottom rim of the plunger, take the strainer out. Seal off the other sink drain if you have a double sink. Plunge!
  • Boiling water poured directly down the drain, after you’ve removed the standing water, can work, but it may take several tries. 
  • Remove standing water and pour a cup of baking soda followed by the same amount of white or apple cider vinegar. When the bubbling stops, stopper the drain and wait 15 minutes. 
  • If the clog is persistent, there may be something solid stuck in what’s called the “P-trap” under your sink. Look in the cabinet under the sink and locate the curved portion of the pipe that has a slip nut on either side. Put a bucket under the trap and remove it. Empty what is in there into the bucket. Was there a clog there? If not, before you put the trap back in place, use a short snake or coat hanger to push through the drain pipe from the side. If there is no clog there, then you may have to snake the portion of the pipe that goes into the wall. 

If none of these solutions work, call Benjamin Franklin Plumbing in the Bay Area, and our team of experienced, helpful technicians will get to work removing the clog quickly and have you back up and operational fast.