Is bleach ok to use on mold?

Author: Dr. Thad Lynch  |  Last update: Saturday, November 1, 2025

While it may come as a surprise, bleach can actually contribute to mold growth on a porous surface, which is one of the main reasons why you shouldn't use this product for mold removal. One of the most important things to know about mold is that it thrives in damp, dark areas.

Is it bad to use bleach on mold?

Bleach is made up of about 90 percent water. Moreover, since molds thrive with moisture, spraying bleach on mold can contribute to further mold growth, especially on porous (permeable) surfaces.

Is vinegar or bleach better for killing mold?

Bleach kills most mold. White vinegar kills slightly more species of mold. In both cases, mold on a porous surface will likely recover because the chemical doesn't penetrate down to ALL the mold. Physical removal is easiest on things like drywall.

What kills 100% of mold?

Hydrogen peroxide, commonly used to disinfect wounds, is active against a wide variety of micro-organisms including mold. It acts by releasing oxygen at a rapid rate, which kills mold by oxidizing the surface and breaking down proteins and DNA.

What happens if you clean mold without a mask?

If you're not wearing any Personal Protective Equipment (PPE), you're inviting all of those mold spores to settle on your clothing, the area you're cleaning, your shoes (allowing mold to travel to other areas in your home), in your eyes, and up your nose into your upper respiratory system.

Don't Use Bleach To Clean And Remove Mold!!

Can I safely remove black mold myself?

Can I clean up black mold myself? Although you can get rid of mild black mold problems yourself, we recommend leaving it to a professional because some species are toxic and cause severe health problems.

What should you not clean mold with?

Biocides are substances that can destroy living organisms. The use of a chemical or biocide that kills organisms such as mold (chlorine bleach, for example) is not recommended as a routine practice during mold cleanup.

What are signs of mold sickness?

Although symptoms can vary, the most common symptoms seen in people exposed to mold indoors include:
  • Nasal and sinus congestion.
  • Eye irritation, such as itchy, red, watery eyes.
  • Wheezing and difficulty breathing.
  • Cough.
  • Throat irritation.
  • Skin irritation, such as a rash.
  • Headache.

Will mold come back after bleaching?

Bleach cannot get to the root of the mold on a porous surface. So while the surface may appear free of mold after using bleach on it, the root of the mold will still be present and growing. And guess what? After a couple of days you'll start to see that mold appear once again.

Can I leave vinegar on mold overnight?

Yes, you can leave vinegar on mould overnight, though this isn't necessary as it usually takes effect after an hour. However, you can't use any type of vinegar, for mould removal you must use distilled white vinegar.

How long to let bleach sit on mold?

affected area of mold and let set for 15 minutes. Rinse the area with a damp towel using clean warm water or by lightly spraying with warm rinse water in a spray bottle (spray bottle #3) and wiping with a clean towel.

Why isn't vinegar killing mold?

Vinegar is good at killing plant matter, that much is true. But it can rarely penetrate deeply enough to kill fungi like mold down to the root. That's why it usually isn't truly effective in cleaning black mold, green mold, and most kinds of common house molds.

What does black mold look like?

Black mold is a type of fungus that looks dark green or black. There are many kinds of black mold, but when most people refer to it, they're referring to Stachybotrys chartarum (S. chartarum). It grows and spreads on materials that contain a lot of cellulose, including paper products, wood products and drywall.

How to get rid of mold on walls permanently?

The only effective way to permanently get rid of mould problems is by reducing the build-up of moisture in your home. This can only be achieved through better ventilation.

Is bleach or hydrogen peroxide better for mold?

Using Hydrogen Peroxide to Kill Mold

Hydrogen peroxide is a good alternative to using bleach to kill mold because it is safe and doesn't damage the environment plus it doesn't leave behinid toxic residue or produce toxic fumes like bleach does.

What spray kills black mold?

Treat the Area. For a natural solution to getting rid of black mold, combine one part baking soda with five parts distilled white vinegar and five parts water in a spray bottle. Alternatively, you can use a chemical-based mold and mildew remover, all-purpose cleaners, bleach or dish soap.

Why is bleach not recommended for mold?

In some cases, bleach will encourage toxic mold to grow where it was not present before. Bleach will only remove the green stain from mold. The surface will appear clean but internal roots will continue to grow. OSHA and the EPA have specifically advised against the use of bleach for mold remediation.

What is the best solution to clean mold?

Chemical or Natural Mold Cleaners
  • Use undiluted white vinegar on hard surfaces in kitchens and baths. Apply it directly to the mold.
  • Make a bleach solution to kill mold. Mix one cup of bleach in a gallon of water. ...
  • Mix a 50/50 solution of ammonia and water. Spray on the surface.

Is it okay to paint over mold?

Painting directly over mold and mildew goes against best paint practices and is not recommended. Mold is a living organism that thrives in a moisture environment so painting (or priming) over it, does not kill it.

Is it safe to clean black mold yourself?

Thus, exposure to the toxicity of black mold can cause harm to our physical health. Cleaning it yourself risks a greatly increased chance of acquiring damaging health conditions by unsettling the toxins into the air. Depending on the frequency of mold exposure, an individual's health can be severely compromised.

Can mold behind walls make you sick?

It irritates the nose and throat, which can lead to both sneezing and coughing as your body tries to get rid of the irritant. Inhaling mold spores can also trigger coughing in people with allergies or an asthma attack, for those with asthma.

What happens if you breathe in mold for a long time?

Chronic Fatigue: Mold forces your body to work harder, leading to persistent fatigue, especially in those with pre-existing conditions. Lung Issues: Prolonged exposure can cause lasting damage to lung function.

What 100% kills mold?

For large amounts of mold, the only method that kills mold 100%, every time, is removing all of the mold-infested materials entirely, and replacing them with new materials.

What is the enemy of mold?

Mold's biggest weakness? Moving air. Mold thrives on moisture and stagnant conditions, but airflow is its natural enemy. By keeping air circulating in your home, you can prevent mold from taking hold.

Why you shouldn't remove mold yourself?

When you see mold, your first instinct may be to roll up your sleeves and do the job yourself. However, doing so can put you and your family at risk! Not only could you spread the mold, but you may not be treating the underlying issue—this means that mold is likely to return or spread.

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