Question
Recently my family was cleaning my grandma’s house. I was using hot water with bleach to wipe things down, thinking I was disinfecting the surfaces. My sister-in-law informed me that when you use hot water with bleach, you deactivate the bleach. I have never heard this before, is this true? She said to only use cold water with bleach when cleaning.
Answer
When mixing up a bleach and water solution for sanitizing or disinfecting of hard, non-porous surfaces in your home, it’s a good idea to use cool tap water to mix the solution. That’s because when you increase the temperature of the water, the sodium hypochlorite bleach active will break down more quickly and could fall below the required concentration for germ kill. That the bleach active breaks down more quickly in hot water doesn’t mean it’s completely deactivated, and I wouldn’t assume you weren’t disinfecting, especially if you were using a new bottle of bleach. However, if you were using an older bottle of bleach and you didn’t use the solution right away, your sister in law could have been right that your solution wasn’t strong enough for germ kill. You can find information on using Clorox® Disinfecting Bleach for disinfecting hard, nonporous surfaces here.
Using bleach in the laundry is different. Regardless of whether you select a hot, warm, or cold wash temperature, adding Clorox® Disinfecting Bleach along with your detergent will give you better cleaning, whitening and stain removal compared to detergent by itself. Not every fabric or garment is suitable for hot water washing, but since the hotter the water the better the cleaning, it’s good to select a hot water cycle when running a bleach load whenever you can.
Remember that bleach has a one-year shelf life when properly stored away from heat or direct sunlight. If you don’t store it properly, the bleach active will naturally break down more quickly. The fact that the sodium hypochlorite bleach active breaks down easily into salt and water is actually a big part of what makes bleach environmentally friendly. But it also makes it important to use the product properly, and I’m glad you asked the question.