Will Bleach Kill Mold?

Does Chlorine Bleach Kill Mold?

No. Bleach combined with certain mycotoxins and VOC’s (Volatile Organic Compounds), can create neurotoxins and brain tumors. The United States Occupational Safety and Health Administration (OSHA) does not recommend using bleach in mold removal.

Chlorine Bleach will not kill mold on porous materials. It bleaches it. Bleach is used as an anti-bacterial disinfectant, but mold is a fungus. You need a fungicide to kill it, not an anti-bacterial. Bleach cannot soak into porous items. it sits on the surface and remains ineffective against mold on things like drywall, wood or carpet..

Since bleach  kills surface mold on porous substances the roots are left alive. This means that the mold can soon grow back. When you use a solution bleach/water solution against black mold or mildew, the bleach quickly vaporize. Water is left behind. What does mold feed on? Moisture. So, your cleaning efforts actually feed the black mold spores and help them grow.

sodium percarbonate aka oxygen bleach kill moldWill Oxygen Bleach Kill Mold?

Oxygen bleach is a better option than chlorine bleach. Oxygen bleach kill mold. Oxygen bleach will kill bacteria, remove stains and deodorize.

Oxygen bleach is also called sodium percarbonate. It comes in powder form which is water soluble. It then breaks down into hydrogen peroxide  and sodium carbonate. These are biodegradable and non-toxic containing no nitrogen or phosphorous. Sodium percarbonate does not create harmful fumes like chlorine bleach. Another bonus is that it will not fade the surfaces it is applied to.

Oxygen bleach can be used with other household cleaners and detergents. Chlorine bleach, however, is toxic if you mix it with vinegar or ammonia.

The ratio of bleach to water is usually between half a cup and one cup, per gallon of water. However, check for the ratio the directions on the oxygen bleach recommend.

You can add the oxygen bleach and water solution to a spray bottle to appply it to the moldy surface. If you prefer, apply it with a cloth, sponge or scrubbing brush.

After you have applied the solution to the mold, let it sit for about 15 minutes. Then thoroughly rinse and wipe the area with water.

You can also make a paste. Add just enough water to the oxygen bleach powder to make it into a paste. After you mix oxygen bleach with water, the solution will be active for about 5 or 6 hours. Dispose of it after this. It is fine to pour the solution down the drain, as oxygen bleach deodorizes drains.

Natural Alternatives

It is generally better to use natural mold killing products. Some good alternative mold killing products are borax and vinegar. Concobrium or Simple Sudz, both soda ash (sodium carbonate) or washing soda will usually work well. Ammonia dissolves some molds and neutralizes the mycotoxins.

Safety Guidelines for Removing Mold

It is important to follow safety guidelines when using cleaners to remove molds. Cleaning up mold increases your risk of exposure up to 1000 times. Note that dead mold can still cause allergic reactions.

Wear a respirator or mask. A TC21-C or N95 particulate respirator works best. (note: rparticulateespirators do not protect against bleach fumes)

  • Wear disposable protective clothing, including rubber gloves, goggles and disposable booties
  • Clean a test patch and see if you suffer any allergic reactions. If you do hire a professional mold remediation contractor rather than risking your health further
  • Be cautious about creating airborne spores. You may consider having your family stay with relatives or friends until your clean-up is complete.
  • Try to isolate the working area with plastic sheeting

The mold cleanup is finished when there is no visible mold remaining. There should be no dust or dirt remaining that could contain mold or mold spores. Routine clearance testing for mold is not necessary. Leaving a few mold spores behind is not a problem if the underlying moisture problem has been corrected. Remember that mold spores are virtually everywhere. Even if all mold and mold spores are removed as part of the cleanup, spores from outside will re-enter that space. The spores won’t be able to grow unless excessive moisture is also present.