How Stainless Steel Removes Odors

One household tip for removing odors from fish, onions or garlic is to rub your hands across the blade of a stainless steel knife. You can even buy stainless steel "soaps"—hunks of stainless steel that are about the same shape and size as a bar of normal soap.

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Why Is Stainless Steel Stainless?

By Anne Marie Helmenstine, Ph.D.

Test this kitchen wisdom yourself, using your nose to take data. Better yet, get someone else to smell your fingers since your own nose will have odor molecules inside it already from exposure to the food. If you have been working with onions, garlic or fish long enough for their "perfume" to be absorbed into your skin, the best you can do is to diminish the scent with the steel. Other types of odors are not affected by contact with stainless steel.

How It Works

The sulfur from the onion, garlic or fish is attracted to—and binds with—one or more of the metals in stainless steel. Formation of such compounds is what makes stainless steel stainless. Onions and garlic contain amino acid sulfoxides, which form sulfenic acids, which then form a volatile gas—propanethial S-oxide—that forms sulfuric acid upon exposure to water. These compounds are responsible for burning your eyes while cutting onions, and also for their characteristic scent. The sulfur compounds bind to the steel—efficiently removing the odor from your fingers.

So, next time you find your fingers and hands smelling from fish, onions or garlic, don't reach for the scented spray; grab a stainless steel knife. Take care, though, to wipe your hands on the flat side, and your limbs will be scentless in no time.