What works best for the disinfecting powers of bleach: hot water or cold water?

Question

I have often heard that it is best to use cold water when using bleach for various purposes.

When bleaching whites cold water is said to work best.

But what about when using bleach just to clean and disinfect things? Do you use cold water or hot water?

Answer 1

I've never heard of using cold water to disinfect anything. The heat itself helps in the disinfecting. I would not be worried about the bleach evaporating, it takes 24 hours for a glass of tap water to loose its chlorine. Or a pot of water MINIMUM 5 minutes at a rolling boil then the cool on its own to loose MOST of its chlorine. Yes it evaporates but not that quickly.

The water should be warm, or "tap hot".

Cold water will set a stain. The instructions on washing machines even say "hot for whites" "warm for heavy stains". Most dish washer detergent contains bleach and dishwasher water is hot. You can disinfect cuts with 1:10 bleach solution that is hot as you can stand it.

If I'm using bleach around my house, I use water between 20oC (room temp) and 40oC (just above body temp) unless its REALLY gross, then I use as hot as my tap will go.

It seems that some of your previous answers here seem to be talking about room temp water, which certainly isn't cold. For myself cold water would be between 0oC and 10oC - like a glass of cold water from the fridge with ice in it. 15oC - 30oC I would say as warm and above 40oC as hot. I don't assume you'd be cleaning with boiling water, 100oC and above.

Answer 2

I suppose it might depend on how thick the material you are disinfecting was?

I would surmise that hot water technically might evaporate the chlorine out faster than cold water would. But if you weren't cleaning up that much, it probably wouldn't matter.

If you feel it must soak, I'd stick to cold water.

Answer 3

hot water causes the bleach to evaporate into the air faster and more readily. which is not fun if you happen to breath the air when this happens.

This, to the best of my knowledge, is why there is a cold-water recommendation with bleach.

Answer 4

Maybe Cold