The idea of “killing” mold is pretty popular, perhaps since it feels so great to beat something that might harm us and our family.
And mold absolutely falls into that category.
It harms buildings and it harms people, who may be allergic to it, who may have it colonize in their body, or who may be poisoned by mold metabolites known as mycotoxins.
Mold affects people through either one of these three mechanisms, or all three of them at the same time.
But “killing” it is a somewhat ludicrous idea.
Dead (nonviable) mold spores can cause the same harms that living (viable) mold spores cause.
Some studies even suggest that when mold is threatened, it produces more mycotoxins in defense of itself.
(Others suggest mold produces mycotoxins all the time, whether under attack or not.)
The object of removing, cleaning, or remediating mold is not to kill it.
It is to remove the mold from the surface or substrate that it’s on, and to get it safely out of the building and off of the property where it will no longer place occupants (you and your family) at risk.
“There is no practical way to eliminate all mold and mold spores in the indoor environment; the way to control indoor mold growth is to control moisture.”US Environmental Protection Agency, “Ten Things You Should Know About Mold,” Last Updated Nov. 4, 2021
Along with the popular crusade of “killing” all mold comes the also-false maxim that bleach is the best way to do so.
But bleach is actually one of the worst ways to “kill,” clean, or remove mold.
If it must be used, use it to remove mold from hard, nonporous surfaces only.
That limits the use of bleach for household mold cleaning/removal to a toilet bowl and toilet tank, a mirror, a shower curtain, and a bathtub—if it’s made of acrylic, cast iron, or another nonporous material.
- Bathroom tile grout – porous.
- Caulk line around your bathtub – porous.
- Fiberglass bathtub – porous.
- Ceramic tile bathtub – porous.
- Shower ceiling – porous.
- Bathroom ceiling – porous.
- Wood frame of your bathroom mirror – porous.
- Fiberglass bathtub – porous
- Laminate bathroom furniture/vanity – porous at edges (exposed particle board).
Why bleach is a poor choice for mold removal
Contrary to very popular belief, bleach does not kill mold on porous surfaces and it can, in fact, contribute to mold growth by giving it the water it needs to grow.
Bleach only whitens the topmost visible layer of mold, but allows the mold’s roots (hyphae) to continue growing.
When applied to porous surfaces—like drywall, painted walls, or the items listed above—the active ingredient in bleach typically evaporates well before it reaches the roots of mold, which, some sources suggest, causes the mold only to reach further downward into these surfaces. You don’t want that.
Long before you ever apply bleach to a moldy non-porous surface, it may already have lost much of its effectiveness (its killing power): The chlorine in bleach evaporates over time, leaving it more watered down than it was when you bought it (and at purchase, it was already about a 3 – 7.5% solution).
The most commonly available bleaches are a solution of 3 – 6 percent active ingredients (sodium hypochlorite—a liquid chlorine), a sudsing agent, and about 90 – 97 percent water.
(Clorox, for instance, is, “a 7.4% sodium hypochlorite solution containing approximately 7.03% available chlorine by weight.”)
Water feeds mold.
Chlorine bleach will kill surface mold on a non-porous surface, but beyond that is pretty ineffective for the above reasons.
Other reasons not to use bleach to clean mold
Additional key reasons why you may want to avoid using bleach to handle household mold:
- A chlorinated bleach solution used on any non-white fabric, whether carpet or clothing, will leave behind white stains.
- Bleach stains aren’t typical; they can completely destroy the color in a fabric, and no amount of cleaning will restore it to its original state.
- Bleach introduces toxic fumes into your home. If you use chlorinated bleach to remove mold growth in a poorly ventilated area (which may already have been a factor in the growth of mold), it can create hazardous breathing conditions for anyone without a respirator.
- Bleach “Causes irreversible eye damage and skin burns.”
- Bleach presents “Hazards to humans and domestic animals.”
- USA Today: “Fact check: It’s true, Clorox Splash-Less bleach does not disinfect surfaces”
Dealing with mold without bleach
There are several good, effective, and reliable ways to remove mold without using bleach.
“Mold can be removed from hard surfaces with household products, soap and water, or a bleach solution of no more than 1 cup of household laundry bleach in 1 gallon of water.”U.S. Centers for Disease Control, “You Can Control Mold”
1. Distilled white vinegar to clean and remove mold
Distilled white vinegar is a natural, non-toxic, and effective way to get rid of mold.
Distilled white vinegar, with its natural antifungal and antibacterial properties, will eliminate ~ 82 percent of known mold species.
Not only does vinegar do an excellent job of treating mold, but it’s also cheap and easy to purchase; pick it up at any grocery store.
The only downside to using vinegar is its pungent odor, but in the grand scheme of things, that’s a pretty minor issue and one that will clear up within the hour.
White vinegar is at its most effective for killing mold when used at full strength, though you can dilute it if you want to minimize the smell.
If you’re dealing with a minor mold infestation, all you need to do is douse the fungus with the vinegar, let it sit for an hour, then scrub it with a soft-bristled brush.
Once the mold is gone, wipe down the area with a wet cloth, then dry it thoroughly.
Use vinegar to tackle mold on/in:
- Soft surfaces (then place in sunlight to dry fully)
- Window seals
- Toilet bowls
Don’t use vinegar on:
- Coated wood floorings
- Use undiluted white vinegar.
- Use only as much white vinegar as you need; you aren’t trying to drown the mold.
- Don’t mix vinegar with bleach.
- Don’t mix with hydrogen peroxide.
2. Hydrogen Peroxide to clean and remove mold
Hydrogen peroxide is another natural and non-toxic option for getting rid of mold.
Although it isn’t toxic, you should still be sure to protect your skin and eyes from coming in contact with it—as long as you’re careful, safety goggles and rubber gloves should do the trick.
Hydrogen peroxide can be used on both porous and non-porous surfaces to eliminate mold.
If you’re treating a porous surface, like wood or fabric, coat the affected area with hydrogen peroxide and let it sit for 15 minutes.
Then wipe the mold away with a clean, wet cloth.
Finally, dry the once-moldy item with a cloth or paper towel.
Non porous surfaces:
If the surface is non-porous, dilute your hydrogen peroxide with an equal amount of water, then apply it to the moldy area.
Once again, you’ll want to wait 15 minutes, but this time, you should rinse the mold and hydrogen peroxide solution away with warm, soapy water.
Finally, you can dry the spot, and that mold issue should now be handled.
3. Baking soda to clean and remove mold
Baking soda is another effective mold-killing agent that you likely have in your home already, making it a very convenient option to use.
Anyone who knows baking soda knows that it’s a very versatile product, and eliminating mold is just one of its many uses.
The easiest way to treat mold with baking soda is to mix it with water in a bowl, creating a 50-50 solution.
That will form a paste, which you can apply directly onto the moldy surface. You’ll want to let the paste dry, then scrub the area clean with a brush.
It’s worth noting that baking soda is milder than vinegar or hydrogen peroxide, and you should probably stick to using it for minor mold problems.
That said, it’s inexpensive, safe for both humans and pets, and totally odor-free.
In fact, it actually will do a better job of getting rid of the musty mold odor than many other cleaning methods.
All of these things make baking soda a fantastic substitute for bleach when treating mold.
4. Lemon juice to clean and remove mold
If you want to replace your mold problem with a fresh, citrusy aroma, lemon juice is the way to go.
Lemon juice is another natural, non-toxic option for killing mold, and its effectiveness stems from its 5% acidity.
You can either squeeze it fresh yourself or purchase it as a concentrate, but either way, you’ll want to use it at full strength for mold treatment.
When using lemon juice to fight mold, your first step should be to apply soap and water to the affected area.
Once you’ve rinsed it off, apply the pure lemon juice directly to the mold, then immediately scrub the area with either a bristled brush or a scrubbing sponge.
You can repeat this process until you’re satisfied with the result, then rinse and dry the spot.
5. Dish soap and water to clean and remove mold
Dish soap and water is a perfectly effective way to clean and remove mold from hard, non-porous items.
Using dish soap and water or detergent and water, scrub off all visible mold on a hard, non-porous surface.
Dish soap and water also works well on some porous surfaces, but if you aren’t sure which is the better option, undiluted distilled white vinegar is often the better choice.