This article originally appeared on GoodHousekeeping.com.

We are huge fans of including vinegar in our cleaning arsenal. It's great for lifting stains, freshening laundry, cleaning windows and much more. Plus, it's inexpensive and all-natural. But vinegar is also acidic, which means that you can't quite use it everywhere. Skip it on these spots:
  
1. Granite and marble countertops

"The acid in vinegar can etch natural stone," says Carolyn Forte, director of the Home Appliances and Cleaning Products lab at the Good Housekeeping Research Institute. Use a mild liquid dish detergent and warm water instead.
  
2. Stone floor tiles

Just like countertops, the natural stone in your bathroom doesn't take kindly to acidic cleaners, like vinegar and lemon. Avoid ammonia, too, and stick to cleaning with a formula made for that surface, such as our Bona Hard-Surface Floor Cleaner.
  
3. An egg stain or spill

If you drop an egg on the floor (or find that your house or car has been the victim of some rambunctious teens), don't reach for the vinegar to help clean up. Just like when you poach an egg, the acidity can cause it to coagulate, making the egg more difficult to remove.
  
4. Your iron

"Vinegar can damage the internal parts of an iron," says Forte. "So don't pour it through to freshen and clean it out. To keep irons from clogging, empty them completely after use, and follow the manufacturer's cleaning instructions."
  
5. Wood floors

It's important to remember that when you clean your wood floors, you aren't actually cleaning the wood, you're cleaning the chemical finish on the wood. This layer protects your floor. Since vinegar is an acid, it will actually break down the finish on your floor over time, reducing shine and leaving a dull appearance. Instead, use a cleaner specifically formulated for wood, like our Bona Wood Floor Cleaner. 
  
6. Certain stubborn stains

Blot, sponge, and try as you might, grass stains, ink, ice cream, and blood won't come out with vinegar alone, says Forte. They tend to set into the fabric quickly or just don't respond to acid, so treat them with a prewash stain remover like Shout Advanced Gel, and launder with a detergent with enzymes (check the package — most stain-fighting detergents have them).