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Our cleaning expert answers: Does bleach kill all germs?

Expertly reviewed by Ketia Daniel

A little over two years ago, people wanted to learn more about cleaning. We weren’t satisfied with merely wiping down surfaces. We wanted to know which cleaners could actually kill the germs that lingered on surfaces so we could reduce the threat of bacteria and viruses finding their way into our bodies and making us sick.

This led to many of us changing our cleaning habits and upgrading the products we use. But do the new practices we adopted really help? How effective is bleach at killing germs? Are there any precautions we need to take when using this product? With the help of our cleaning expert, we’ll take a deep dive into the subject to find out the answers to these questions and more.

What is bleach?

The main ingredient in chlorine bleach is sodium hypochlorite. Sodium hypochlorite is a chemical that is made from sodium, oxygen and chlorine. It functions as an oxidizer. Without getting too scientific, an oxidizer breaks down chemical bonds by releasing oxygen molecules. When removing stains, bleach breaks down the bonds of a chromophore, the part of a molecule that has color. Once broken down, the molecule will no longer reflect color in the visible spectrum. This absence of color is perceived by our eyes as being white. This is how bleach “whitens.”

Bleach does the same thing to germs. When it comes into contact with pathogens, it oxidizes those molecules, effectively killing the germ. Additionally, when sodium hypochlorite is added to water, hypochlorous acid forms. Scientists believe this also plays an active role in killing some germs and bacteria. 

Nonchlorine bleaches do not contain sodium hypochlorite. They still oxidize, but they are not as potent as chlorine bleaches when it comes to disinfecting surfaces.

Does bleach kill all germs?

Ketia Daniel is the founder of BHM Cleaning Co. and our cleaning expert at BestReviews. She explained why, as potent as bleach is, it might not be as effective at killing germs as you are hoping — unless you know how to use it.

Use bleach last

While bleach is effective at killing up to 99.99% of germs, Daniel reminded there are factors that can make bleach less effective. First, she cited how bleach works. She explained that it is highly reactive and doesn’t discriminate when it comes to the substance it’s breaking down. Bleach will break down chromophores just as readily as it will break down pathogens. In other words, bleach will react with whatever substance it comes in contact with first. If there is a lot of dirt on a surface, bleach will break down bonds in the dirt. This will diminish the bleach’s potency and may even make it ineffective as a disinfectant.

Daniel strongly recommended thoroughly cleaning a surface to remove dirt and grime before treating that surface with bleach. If you do this, the bleach will target the pathogens instead of the dirt, making it much more effective.

Bleach needs time to work

Disinfecting with bleach is a chemical process. It takes time to occur. If you spray down a surface and quickly wipe the bleach off, it won’t have time to react with the germs. This means you won’t be disinfecting the surface. If you are using a cleaning product, read the directions. Most will offer a minimum amount of time to let the bleach sit before wiping away. If there are no cleaning directions on the container, it is best to let bleach remain on a surface for 10 minutes before wiping it away.

What are the dangers associated with using bleach?

Daniel pointed out that, as effective as it is, working with bleach is not without its hazards. She said you never want to work with bleach without wearing cleaning gloves. She also offered an important tip, suggesting homeowners use splash-free bleach. Splash-free bleach is formulated to be thicker than plain bleach, and it comes in a container that has a controlled spout, which reduces splashes that may occur while pouring.

Daniel noted, however, that as careful as you are, drops of bleach can still find their way onto your clothing. When cleaning, she said it is best to wear clothing that is either white or you don’t care if it gets bleach-stained.

Our cleaning expert also cautioned that bleach is not safe to use on all surfaces. It can give stone tile a whitewash that will require refinishing, and it can corrode stainless steel. Always read the usage directions before applying bleach to any surface. Additionally, it can help to test a small inconspicuous area before cleaning to make sure the bleach doesn’t damage the surface.

Last, and most important, Daniel warned to never mix bleach with anything but plain water. Bleach can react with many other chemicals and create a toxic gas. You should even be careful about using buckets that once contained other cleaning chemicals. It is safest to have a designated bucket that you only use for bleach.

What do I do if I get bleach on my skin or in my eyes?

If bleach does splash on you while using, it is important to treat the situation immediately. Whether it is in your eyes or on your skin, medical advice from sources, such as the Mayo Clinic, recommend rinsing the location with “lukewarm tap water for at least 20 minutes.” The best way to do this is to remove your clothing and contact lenses (if you are wearing them), and stand in the shower, allowing the water to run down your body rather than spraying it directly on the affected area. Do not rub the area where you were splashed, as this will aggravate the situation. While you are rinsing, a friend should call your doctor or emergency services to get directions on your next step.


Q. Can I use bleach on mold and mildew in the shower?

A. If you have an individual in your family who is sensitive to mold, it can trigger an allergic response and make breathing difficult. It is important to keep mold growth under control. Daniel said if you have a mold problem in your bathroom — as many of us do — using a bleach-based bathroom cleaner can help. Simply spray the cleaner directly onto any mold or mildew growth that you find in the shower. For the cleaner to be effective, however, you must read and follow all directions on the container. It takes time for bleach to do its job. You can’t just spray it on and quickly wipe it off.

Q. How do I disinfect my child’s plastic toys?

A. If your child likes playing with plastic toys and plastic building sets, such as Duplo blocks, it is important to realize that some germs can live on plastic surfaces for as long as 24 hours. This means it is important to thoroughly clean those toys at least once each week or immediately after a play date. Daniel said you can kill the germs on plastic toys by mixing 1/4 of a teaspoon of bleach with 1 quart of cold water. You can then use this solution to soak the toys to kill germs. Alternatively, you can fill a spray bottle with the solution and spray down the toys.

What you need to buy for cleaning with bleach

Clorox Concentrated Germicidal Bleach

This high-concentrate bleach cuts usage requirements in half, stretching your dollars twice as far. It is suitable for use on food-contact surfaces and requires a five-minute wait time before wiping.

Where to buy: Sold by Staples and Amazon

Pure Bright Liquid Bleach

Pure Bright is a liquid laundry bleach that not only removes stains and odors, but it disinfects as well. It is fragrance free and comes in a gallon bottle.

Where to buy: Sold by Amazon and Staples

Clorox Healthcare Bleach Germicidal Wipes

These one-step germicidal wipes are ready to use. They can kill most germs in three minutes or less, and they meet the EPA criteria for use against SARS-CoV-2. Each container comes with 150 wipes.

Where to buy: Sold by Staples and Amazon

Cloralen Splash-Free Bleach

Cloralen bleach is specially formulated to be splash free. It can be used on bathtubs, showers, sinks, ceramic tiles and other nonporous bathroom and kitchen surfaces. It is tough enough to remove wine, grass and coffee stains.

Where to buy: Sold by Home Depot

Lysol Multi-Purpose Cleaner

The fast-acting formula in this spray kills up to 99.9% of viruses and works on hard, nonporous surfaces in about five minutes.

Where to buy: Sold by Staples and Amazon

Fantastik All-Purpose Cleaner

Fantastik’s multi-surface cleaner has a powerful bleach formula that makes it effective on countertops, sinks, tiles and other hard surfaces. The fresh scent keeps your home smelling as clean as it looks.

Where to buy: Sold by Amazon and Staples

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Allen Foster writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.

BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers.

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