Storing bleach for water purification and general cleaning needs

One of the easiest ways to disinfect water is to use 8 drops of bleach per gallon of clear water. For that reason I stock up on bleach when it’s on sale. We always have a few gallons in the laundry cupboard for general use and water purification needs.

I haven’t rotated my storage as quickly as I thought I would, and now I need to know if that bleach can still be used. Does bleach go bad? Do you know the self life of bleach?

The active ingredient in liquid bleach is sodium hypochlorite. Over time bleach naturally degrades into salt and water in the bottle. The major factor determining the rate of decomposition is temperature.

The higher the temperature the faster the active ingredient is lost; older product also decomposes more rapidly. Manufacturers compensate for this by adding more bleach during their summer production. Generally, average storage conditions should stay around 70 degrees F.

Another factor is exposure to sunlight. Bleach is sold in opaque bottles because increased light will cause the liquid bleach’s active ingredients to break down.

Depending on its use, bleach is also susceptible to contamination in the laundry room due to exposure to humidity. You should always store bleach in its original container and keep it tightly capped.

– Bleach has a 12-month shelf life beginning with the day of manufacture.

Know the Code

Clorox® has provided their code system to assist in determining the shelf life of their product. An example of their code system (e.g., G18099) on a bleach bottle would be as follows: The first two characters (G1) identify the plant or location of the manufactured product. The third character (8) is the year the product was made or 2008. The fourth, fifth, and sixth characters stand for the day of the year the product was manufactured. For example, it would be the 99 day or April 8th. You only need to use the first six digits to decipher the code. (source)

General Disinfecting

If you are making a disinfecting solution for your counter tops, you should mix a new batch daily. Clorox® Bleach is registered with the EPA as a disinfectant and is very effective if used following these instructions:

Make a standard disinfecting bleach solution using half cup of regular bleach added to 1 gallon of water. This mixture will be exposed to light, which will help it degrade faster. To simplify things you could make a smaller amount with 2 tablespoons mixed in 4 cups water.

This can be used over several days for general countertop cleaning. If you are cleaning up after things that are highly likely to spread bacteria, like raw meat, you would want to use a freshly mixed solution every day.

Water disinfecting with liquid bleach

If tap water is clear:

1. Use bleach that does not have an added scent (like lemon).

2. Add 1/8 teaspoon (8 drops) of household liquid bleach to 1 gallon (16 cups) of water.

3. Mix well and wait 30 minutes or more before drinking.

If tap water is cloudy:

1. Use bleach that does not have an added scent (like lemon).

2. Add 1/4 teaspoon (16 drops) of household liquid bleach to 1 gallon (16 cups) of water.

3. Mix well and wait 30 minutes or more before drinking.

Remember that containers may need to be sanitized before using them to store safe water for emergency survival:

1. Use bleach that does not have an added scent (like lemon).

2. Add 1 teaspoon (64 drops) of household liquid bleach to 1 quart (32oz) of water.

3. Pour this into a clean storage container and shake well, making sure that the solution coats the entire inside of the container.

4. Let sit at least 30 seconds, and then pour out solution.

5. Let air dry OR rinse with clean water that has already been made safe, if available.

What about granular calcium hypochlorite?

Some people store pool shock as a viable water purification alternative to bleach. This kind of chlorine is called Calcium Hypochlorite (HTH) (Amazon) vs sodium hypochlorite (SH)

According to the EPA you can use granular calcium hypochlorite to disinfect water. A 1-pound bag of calcium hypochlorite in granular form (pictured above) will treat up to 10,000 gallons of drinking water.

These are the instructions from the EPA website:

Add and dissolve one heaping teaspoon of high-test granular calcium hypochlorite (approximately ¼ ounce) for each two gallons of water. The mixture will produce a stock chlorine solution of approximately 500 milligrams per liter, since the calcium hypochlorite has available chlorine equal to 70 percent of its weight.

To disinfect water, add the chlorine solution in the ratio of one part of chlorine solution to each 100 parts of water to be treated. This is roughly equal to adding 1 pint (16 ounces) of stock chlorine to each 12.5 gallons of water to be disinfected. To remove any objectionable chlorine odor, aerate the disinfected water by pouring it back and forth from one clean container to another.

You can use chlorine tablets to disinfect filtered and settled water. Chlorine tablets containing the necessary dosage for drinking water disinfection can be purchased in a commercially prepared form.

These tablets are available from drug, sporting goods stores, and pool supply companies. They should be used as stated in the instructions. When instructions are not available, use one tablet for each quart, or liter, of water to be purified.

However, you should only use calcium hypochlorite if you can verify the quality and strength of the tablets. From the CDC Safe Water Page:

“Chlorine tablets and/or HTH (also named calcium hypochlorite) are widely available in some areas. A number of potential users of the SWS know that these tablets are used to disinfect water. Unfortunately, we have also found that many people have different levels of knowledge regarding appropriate dosing instructions, which is a concern because the tablets vary significantly in strength. In Haiti, a small saran wrap bag of approximately 100 HTH pellets is widely available and inexpensive. However, the pellets vary in size, the quality of the pellets is unknown, and, depending on impurities in the manufacturing process, they can degrade quickly. In other countries, very high strength tablets may be sold which, when added to water for disinfection, leave a strong, unpleasant taste. It is important for users to know the quality and strength of HTH and/or chlorine tablets and understand the appropriate dosing strategy before attempting to use them for drinking water treatment; in most instances, however, this is impossible for users to do. For these reasons a sodium hypochlorite solution is likely to be a better option.”

Direct contact to the calcium hypochlorite powder can be irritating or corrosive. The product is therefore usually pelletted to avoid dust generation and to control exposure during handling or transportation.

STORAGE CONDITIONS: Keep product tightly sealed in original containers. Store product in a cool, dry, well-ventilated area. Store away from combustible or flammable products.

Keep product packaging clean and free of all contamination, including, e.g., other pool treatment products, acids, organic materials, nitrogen-containing compounds, dry powder fire extinguishers (containing mono-ammonium phosphate), oxidizers, all corrosive liquids, flammable or combustible materials, etc.

DO NOT STORE AT TEMPERATURES ABOVE: 125 Deg.F Storage above this temperature may result in rapid decomposition, evolution of chlorine gas and heat sufficient to ignite combustible products.

PRODUCT STABILITY AND COMPATIBILITY SHELF LIFE LIMITATIONS: Shelf life (that is, the period of time before the product goes below stated label strength) is determined by storage time and temperatures. Do not store product at temperatures above 125 Deg.F.

When stored under moderate temperature conditions, product will maintain stated label strength for approximately two years. Prolonged storage at 95 Deg.F or above will significantly shorten the shelf life. (source)

So here’s the bottom line – yes bleach goes bad.

If Stored Properly the shelf life of Sodium hypochlorite bleach will last for 12 months past the manufacture date.

Calcium hypochlorite (kept in powder form) will last for 24 months past the manufacture date.

Which kind of bleach do you have in storage and why? Leave a comment below.

Disclosure: This post contains affiliate links. Thank you for supporting PreparednessMama in this way!