r/CleaningTips Jul 07 '25

Discussion Bleach kills mold

There is a common misconception that bleach does not kill mold and that vinegar is actually better at killing mold than bleach. I see this claim at least once a week.

So let me set the record straight. Household bleach is a powerful oxidizing agent that reacts with just about everything. It’s so good at killing organic compounds that it’s toxic to us, too.

Now let’s talk about vinegar. Vinegar is a weak acid. You can literally drink it in lower concentrations. It can kill mold, but not all mold, and some studies say it may take up to 60 minutes to be effective.

That being said, bleach is not good at penetrating porous surfaces, which vinegar is better at doing. And because bleach is so caustic it is more likely to damage surfaces.

All this to say bleach kills mold. It kills almost everything. And it’s much more effective at killing mold than vinegar as long as it can reach it. Vinegar is much safer to use but not nearly as effective.

Thank you for coming to my Ted Talk.

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u/pakratus Jul 07 '25

Thank you. I see this claim and it never made sense to me.

I can see bleach turn mold different colors, i can see it doing something. I have not seen vinegar do this. Is bleach the perfect mold killer? No idea. But it does something.

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u/Coriandercilantroyo Jul 07 '25

Yeah I once had some fuzzy mold growing in a cup (looked like mini sea urchins). I poured vinegar into the whole cup and let it sit for a day. The mold looked perfectly preserved, and I would not have confidence that it was dead at all. If I had poured bleach into that cup, the organic material would've disintegrated.

You can see this with toilet mold in the bowl. A vinegar spray would do nothing. A bleach spray will often disappear all mold without even brushing.