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Does Bleach Kill Bacteria, Viruses, and Mold?

Here are tips to help homeowners understand the best ways to get rid of existing spores or prevent new growth.


Reading Time: 5 minutes

Written by Eunice Samson

Does bleach kill bacteria, viruses, and mold

Mold is a common problem in many households. In fact, global studies have found that around a big portion of homes contain Cladosporium molds which are often dark brown or black, others contain penicillium molds which can appear in shades of blue or green. Not only is mold not particularly nice to look at, but it can also cause a wide range of health problems, especially in children with weak immune systems or in adults who suffer from allergies or asthma. Unfortunately, there’s a lot of different and confusing advice on how to clean mold that has resulted in many homeowners not fully understanding the best ways to get rid of existing spores or prevent new growth. So, does bleach kill bacteria, viruses and mold?

The short answer is yes, but with considerations. It is proven that bleach is great for cleaning mold on smooth non-porous surfaces such as ceramic tiles and sinks. However, it has a harder time on porous surfaces, such as concrete or wood because the mold ‘hides’ within the material.

Bleach is a powerful cleaner that can attack mold spores that have started to grow in your home. This is because it contains the active ingredient sodium hypochlorite which is effective at killing viruses, bacteria, and fungi by attacking their protein structures and deforming them.

Cleaning mold with bleach: You may have noticed that mold seems to grow quicker in the bathroom and kitchen – this is because these rooms often have ideal conditions for growth: they’re warm, humid, and damp. Before you start to clean with bleach, be sure to spot test the area first - especially if you are cleaning mold off walls with bleach. Here’s a step-by-step on how to use bleach against molds: Spray – Use a bleach spray – we recommend the Domex Multi-Surface Spray or a bleach product that is meant to clean surfaces – to cover the area. It’s convenient because you don’t have to mix anything up and the spray gets into hard to reach corners. Allow it to soak in for a few minutes. Wipe – With a clean cloth, wipe down the surfaces you have sprayed. Any build-up should be easy to remove, but pay attention to any trouble areas. Ensure you wear gloves and protect your eyes and skin while you’re working! Assess – Take a step back and reassess if you need to spray again on particular areas.

Once you’ve cleaned the area, it’s important to wash your rags, sponges, and cleaning cloths to ensure you don’t encourage the spread of bacteria and fungi.

How long does it take bleach to kill germs and mold? Not very long. If you’re cleaning with bleach to disinfect the home and kill germs, leave it to settle for at least five minutes before wiping away. If you’re cleaning mold, leave the bleach on for half an hour for best results. Just make sure the area is out of reach of kids or pets because bleach can be a dangerous chemical if left unattended.

Can bleach prevent mold from growing back? Yes. Regular maintenance should also make a big difference in regrowth of molds.

Cleaning mold with bleach safely Whichever bleach product you choose to help tackle mold in your home, it’s important to stay safe while cleaning. Keep your windows and doors open when using bleach to improve airflow and reduce fumes, and always wear gloves and any other necessary protective clothing. These cleaning solutions can irritate or even “burn” the skin. And always keep children and pets away from the area until it’s safe.

Using a reliable effective bleach that is meant for cleaning the home – like Domex – not only effectively kills mold, viruses and bacteria, but also helps to protect your family from illness and infection.

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Originally published