Acetic acid

White vinegar is a common solution of acetic acid (5-percent strength; pharmacies and photography shops sell a 10-percent solution). While not a good cleaning agent in some applications, white vinegar can be used as a rinse to neutralize the alkaline cleaners used in floor stripping.

Vinegar will also remove lime scale on plumbing fixtures and in appliances such as coffee makers and humidifiers. Add vinegar to the appliance and turn it on briefly to warm the acid; then shut it off and let it sit for at least an hour. Turn coffee makers back on to “brew” the acid-lime solution out of the machine; empty the solution out of humidifiers, brushing away any remaining scale that may be visible. In both cases, run plenty of clean water through the machines to flush out any remaining acid.

 

Vinegar is reported to have germ-killing properties and is sometimes recommended as a low-toxicity method for sanitizing surfaces.

 

Reference:
Don Aslett in The Cleaning Encyclopedia: Your A to Z Illustrated Guide to Cleaning Like the Pros.