Why Does Dish Soap Cut Grease?

The miniscule molecules in liquid dish soap do a big job when tasked with cleaning pots, pans, floors, cars and RVs.

Man washing pan while woman standing in background in kitchen
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The miniscule molecules in liquid dish soap do a big job when tasked with cleaning pots, pans, floors, cars and RVs.

No matter what the size of what you are cleaning, dish soap works quick to remove dirt, grime and grease from slick, porous or other common surfaces. Grease cutting dish soap works to lift and separate grease, oil and grime by surrounding, breaking down and suspending the unwanted substances in water so that they can be washed away quickly.

The Basics of Dirt

From the baked on crusty pans to the cakes of dirt on bumpers and windows, behind the stuff you are attempting to clean off with bubbly passes of dish soap is a layer of oil. Even dirt has tiny bits of oil that makes it cling to hands, window sills or cars.

Oil molecules are large and don't have poles that end with different electric charges. Water molecules are attracted to each other, which makes it fluid, rather than oil. Introduce soap to these two opposites and an attraction begins that means the end of the clingy oil's tenure on the surface of the item you are cleaning.

How Soap Works to Clean Dishes and Surfaces

Soap is made up of molecules that have two completely different ends. One end of the soap molecules is hydrophilic, which mixes well with water. The other end of the soap molecules is hydrophobic, which repels water.

These two very different molecules work together to break down oil and grease into smaller drops that mix with water and, therefore, can be lifted from the surface of the pots and pans, countertops or another slick surface. The hydrophobic end of the soap molecule will attach to the grease or oil while the hydrophilic end of the molecule attaches to the water.

Once the oil is broken up into smaller drops, it is suspended in the water by the soap molecules. These drops are easily washed away from the surface of your items.

Ingredients that Matter

Originally, soap was created by mixing a fatty acid, such as that from rendered animal fat, and an alkaline substance, such as the ashes from the fire used to melt the cow or sheep fat. The result wasn't pretty; it looked more like a thick, brown curd. But it was extremely effective in cleaning all sorts of things.

Eventually, this evolved into the liquid dish soap that sits on countertops around the world. One of the more common brands, Dawn, uses sodium lauryl sulfate that bonds with oil and grease for quick removal. The list of Dawn dish soap ingredients includes:

  • Water
  • Sodium lauryl sulfate
  • Sodium laurethsulfate
  • C12-14-16 dimethyl amine oxide
  • SD alcohol
  • Sodium chloride
  • PPG-26
  • Pei-14 PEG-10
  • PPG-7 copolymer
  • Cyclohexanediamine
  • Phenoxyethanol
  • Magnesium chloride
  • Methylisothiazolinone
  • Fragrance,
  • Yellow 5
  • Blue 1

Dawn Liquid Soap Facts

Dawn dish soap facts are rather impressive for such a simple product. It was found to be the most effective way to remove crude oil from birds and animals affected by a major spill in the Pacific Ocean in 1989.

It is often used as a dog shampoo to effectively repel fleas, although that has not been proven in any official study. It is also used to repel ants and insects in a mix of 8 ounces of water and a few drops of Dawn.


Kimberley McGee

Kimberley McGee

Kimberley McGee is an award-winning journalist with 20+ years of experience writing for a variety of clients, including The New York Times, Las Vegas Review-Journal Home section and other national publications. As a professional writer she has researched, interviewed sources and written about home improvement, interior design and related business trends. She earned a B.A. in Journalism from the University of Nevada, Las Vegas. Her full bio and clips can be viewed at www.vegaswriter.com.