Diluting Bleach for Sanitization

Diluted bleach is a great value for a sanitizer.

Food-safe disinfection

Note that this is insufficient for 2019-nCoV disinfection. See the next section.

If you dilute your bleach properly, you can sanitize food surfaces without rinsing the surface before use. For such a food-safe dilution, you want a 200 ppm solution. In general, use one-half teaspoon per Liter of water or 2 teaspoons of bleach per gallon of water.

But how does one calculate the precise amount of bleach to use, especially when your bleach is an atypical concentration?

My bleach label says it "yields 5.8% chlorine." So for 1 Liter of sanitizer solution, I need to use

Dilution Formula

of 5.8% bleach per 1 Liter of water. Or

Dilution Formula

of 5.8% bleach per 1 gallon of water.

Sterilizing 2019-nCoV

The CDC says that a dilution of 4 US teaspoons of bleach to 1 Quart of water is effective against the coronavirus. (Or 21 mL of bleach per 1 Liter of water.) Leave on the surface for 10 minutes. Note that his is beyond the food-safety concentration, so wipe surfaces with a clean, damp cloth before contact with food. Also note that this doesn't consider the strength of the bleach.

Expiration

Ensure your bleach is not expired. Bleach is also inactivated by heat and light. Use an opaque container, and store it in a cool, dark place. If sunlight can penetrate the container, mix fresh daily.

Cleaning and disinfecting

For an dual-purpose cleaning and disinfecting solution, I combine water, some Simple Green concentrate, and the appropriate amount of bleach. See the Simple Green label for dilution recommendations.

Simple Green is a good choice because it is an ammonia-free cleaner, so you can mix it with bleach. It will lose the green color, but that doesn't matter. It's pretty cheap; a gallon of concentrate typically costs $10 to $12.

Inorganic matter deactivates bleach. This means that bleach won't work if there's a lot of dirt or grime or grease present. Clean all that junk off and then spray again to disinfect with the bleach.