Can You Pour Bleach Down the Sink?

Bleach, used for cleaning and disinfecting myriad areas in the home, might seem harmless enough. But while there is no skull and crossbones or a long list of cautions on the label, chlorine bleach is a toxic substance to be used with care. While its strong scent can be irritating, how safe it is for humans, drains and the environment is a question that should be kept in mind while cleaning.

kitchen mixer tap and sink
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Kitchen sink.

Avoid the Drain

Although good at cleaning and disinfecting, bleach doesn't help keep drains clear or remove built-up gunk, since it has no effect on things like grease, food scraps or hair. And bleach, which breaks down mostly into saltwater when it reaches waste water treatment or septic systems, doesn't have much impact by itself on the environment. But the most important thing to know is that bleach, a liquid compound of sodium hypochlorite, should never be mixed with ammonia or acids, or a potentially life-threatening situation could develop. Both ammonia and acids are found in other common household products that might also find their way down drains.

Gas Matters

Chlorine bleach mixed with ammonia creates chloramine gas, and with acids, chlorine gas. Both of these gases can cause coughing and breathing problems and, at high-enough levels, vomiting, pneumonia or even death. Ammonia is found among products including glass and window cleaners and some paints. Among the products that include acids are drain cleaners, vinegar, some glass and window cleaners, automatic dishwasher detergents and rinses, and rust removers.

What to Do

One way to clear a slow drain is to pour a kettle of boiling water down it or use methods such as a plumber's snake or plunger. Clean drains by periodically pouring down 1/2 cup of baking soda, followed by 1 to 2 cups of plain white or apple-cider vinegar. Let it work for five minutes. Then, run hot water for 30 seconds, and follow that with cold water.

Garbage Disposals

Horizon Services, a provider of plumbing services, notes that the only thing that should be put down a garbage disposal is certain types of food, while bleach and household cleaners can damage blades and pipes. It suggests using baking soda and letting it sit for several hours to remove odor-causing mold and mildew that accumulates in garbage disposals. For really strong and stubborn odors, it recommends pouring 3 to 4 tablespoons of borax down the disposal, letting it sit for an hour, then flushing it down with hot water.