It’s in all our homes, the ubiquitous bottle of bleach, and we use it every day to disinfect, clean, and bleach our white clothing. However, with a growing awareness of our environment, you might wonder if it is safe to throw it away?

You may dispose of bleach by first diluting it generously with water and pouring it down your drain or toilet bowl (septic tanks included). Manufacturers design bleach to fall into the safe parameters of the wastewater and sewage systems without causing harm to the environment.

If handled according to the manufacturer’s specifications, bleach should not cause you any serious issues when it comes to disposal. However, you should ensure that you never mix it with other agents that may make it toxic to yourself or the environment. Here are some safe ways to get rid of your bleach after you use it.

How to Safely Dispose of Bleach

The key to getting rid of household cleaning agents such as bleach is to follow the instructions on the product label. If there are no special instructions, look at how the product is used. As bleach is a water-soluble cleaning agent, you should be able to flush it or pour it down the drain with running water.

If you use your bleach product according to specifications, most household bleaching agents are safe for use with existing wastewater treatment systems. This use would typically include septic tank systems as well.

The bacteria in a septic tank system are far more resilient than you imagine. They may tolerate up to 1.3 gallons (5 liters) of cleaning agents such as bleach at a time without serious effect.

Pouring Bleach Down the Drain

You can pour bleach down the drain, but when you do, ensure that you add plenty of water to it and run the tap for several seconds after pouring it out. Once you dilute the bleach, it further dilutes in industrial wastewater before the chlorinated by-products enter a wastewater treatment plant.

Activated sludge treatment and process combined with natural biodegradation and absorption should reduce the concentration to a non-harmful level.

Pouring Bleach Down the Toilet

The same applies to disposing of bleach via your drain. Natural biodegradation and the sewerage systems’ municipal treatments neutralize most of the harmful effects of bleach concentrations. Your toilet water dilutes the bleach, and flushing increases dilution, disposing of bleach safely.

If you are pouring out large amounts of bleach (over 0.25 gallons), you should separate the bleach into two batches and flush each individually. You should also ensure that your toilet bowl is suitably filled with enough water to dilute the bleach properly, or you should add some more water into the bowl before flushing.

Pouring Bleach Down Septic Tanks

A clinical study of the effects of household chemicals such as bleach on septic tank microorganisms showed that even entire package disposal in maximum concentrations was well within the no-effect concentration for serious bacteriological action.

The bacteria in septic tanks recover quickly from contaminants such as bleach, provided you supply the necessary dilution.

Laboratory and field studies showed that 1.3 gallons of undiluted sodium hypocrite bleach in a standard 1,000-gallon septic tank would still not significantly harm the septic tank’s bacterial activity. That would be a significant amount of bleach for a typical household, so disposing of your bleach in your septic tank shouldn’t cause you undue concern.

Can You Dump Bleach Outside?

You may dump your bleach outside, provided you dilute it copiously. Small amounts of highly diluted bleach in low concentrations may benefit your plants, as chlorine is a highly useful micronutrient necessary for plant growth. However, higher concentrations may harm or even kill your plants.

Sodium hydrochloride is highly reactive and breaks down by sunlight to compounds commonly found in the air. When mixed with water and soil, sodium hypochlorite does not accumulate and rapidly breaks down into:

  • Sodium
  • Hypochlorite ions
  • Hypochlorous acid molecules

Sodium hypochlorite increases the salt content of the soil and displaces other mineral nutrients your plants need in the earth. When chloride accumulates in a plant, it may reach toxic levels causing leaf burn, dieback, or plant death. 

A study showed that sodium hypochlorite reduced plant roots’ water content and caused high concentrations of chloride toxicity. Chlorine moves between membranes of plants limiting growth and water transport between cells. It also inhibits photosynthetic pigment production necessary for a plant to photosynthesize.

How to Dispose of Bleach Containers

Your household bleach will often have instructions for safe disposal. You should always ensure that your bleach bottle is empty before disposal. If you have a small amount left, you may offer it to someone else or dilute it and pour it into your toilet or sink.

If the bottle is recyclable, the manufacturer will typically add a PET or HDPE sign. If so, you should ensure that you thoroughly rinse the container of any bleach you may leave behind. As recycling specifications may differ from place to place, enquire from your local recycling department whether they accept used bleach containers in their recyclables.

Why Is It Important to Dispose of Bleach Safely?

The main ingredient in your household bleach is a chemical called sodium hypochlorite or NaOCl. NaOCl is a potent oxidizing agent in liquid form, is usually yellowish-green in color, and has a distinct smell. Today it is ubiquitous in American homes as a cleaning or bleaching agent.

Diluting your household bleach with enough water should make it safe to dispose of in your drain. In fact, The EPA even suggests placing unscented or colored household bleach in water for disinfection purposes in emergencies.

Sodium Hydrochloride added to water creates hypochlorous acid, which penetrates the resistant surfaces of microorganisms and is effective against many bacteria, fungi.

Despite its disinfection capabilities, if incorrectly stored, mixed, and used, bleach may be harmful to yourself and the environment. Bleach can cause harm in the following ways:

Respiratory Dangers

Sodium hypochlorite mixed with vinegar, hydrogen peroxide, or other chemicals may release chlorine gasses. Chlorine gas exposure reactions may include burning of the throat and/or eyes. High concentration may even cause narrowing of the airways, fluid build-up in the lungs, and serious lung injury.

Related: Can You Mix Bleach and Baking Soda?

Ingesting Bleach May Be Toxic

Gargling or swallowing bleach can cause burns on the esophagus and even death in high concentrations. The CDC notes that drinking bleach can be fatal at between 7-18 ounces of concentrations between 3-12%.

Harm to Skin

Even in low levels, bleach may affect the skin, but high concentrations of bleach may cause a host of secondary symptoms. Bleach is corrosive, which means it may irritate or burn the skin or eyes.

It is also possible to have allergic reactions to bleach on your skin, leading to painful burns. Repeated or prolonged contact with a high concentration of bleach may cause burning pain, redness, swelling, blisters, painful red welts, and/or severe eye injury.

Environmental Hazards of Bleach

Sodium hypochlorite is highly toxic to fish and aquatic organisms and may cause necrosis, chlorosis, and leaf abscission when applied directly to plant life. However, the EPA does not consider household bleach poured down a drain a serious environmental threat.

Bleach reacts with organic material in the sewerage system, is not bioaccumulative, and is unlikely to pose a toxic or reproductive hazard to aquatic life. By-products formed by hydrochloride-containing products are biodegradable and effectively treated at water plants.

Sodium hypochlorite can cause harm to plant life in concentrated form, so you should take care when working with bleach in your garden. Only throw out your bleach if it is in highly diluted form around grass and other plant life.


Household bleach performs several vital functions in the home and should not pose a risk to yourself or the environment if used correctly and with care. Bleach may be hazardous if used contrary to its specifications, especially mixed with other chemicals. If you use bleach as it is specified, you may safely dispose of your trusty bleach down the drain or toilet without worry.

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