There is a novelty on the market that has gained the approval of the cooks, a soap made of stainless steel. Known as stainless soap, this product can easily remove many unpleasant odors from your hands, especially those left by garlic and onions.
Its use is as follows: first wash your hands with a common soap or soap, rinse to remove the foam and, under running water, rub the stainless steel soap with your hands, passing it throughout, including between your fingers, for about 30 seconds.
A very good aspect of this product is that it does not wear out, that is, it can be used “forever”. It is also environmentally friendly, has no perfume and its prices range from R$9.00 to R$100.00.
To understand how this soap manages to accomplish this feat, let's see the composition of unpleasant odors and stainless steel.
Sulfur compounds, that is, those that have one or more sulfur atoms in their structure, are responsible for some of the worst smells in the world. Any food that has large amounts of sulfur, such as garlic and onions, generate these bad smells.
In the case of garlic, it has dipropenyl disulfide as an active ingredient, with two sulfur atoms in the center:
CH2 ═ CH — CH2 — s — s — CH2 — CHCH2
When we cut or mash garlic, its alinase enzymes transform the dipropenyl disulfide into allicin (structure below), then mild oxidation occurs. Allicin easily loses its oxygen atoms and converts back to the disulfide, which is more volatile. Allicin is the substance that generates the unpleasant odor of garlic:
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CH2 CH2 — CH2 — s — s — CH2 — CH2 CH2
The unpleasant smell of garlic that stays on your hands comes when you cut or crush it
Other unpleasant odors in many foods are also caused by carboxylic acids.
The stainless steel from which the aforementioned soap is formed is a metallic alloy formed by 74% of steel (which, in turn, is made of of approximately 98.5% of iron, from 0.5 to 1.7% of carbon and traces of silicon, sulfur and phosphorus), 18% of chromium and 8% of nickel. This alloy practically does not oxidize, which is why it is called stainless.
Thus, makers of this product say the odors are eliminated by the steel's ability to catalyze the oxidation of the acids and sulfur responsible for the odors.
It's also worth remembering that you can get rid of the smell of garlic on your hands by rubbing your hands on other kitchen utensils that are made of stainless steel, such as cutlery.
By Jennifer Fogaça
Graduated in Chemistry
Would you like to reference this text in a school or academic work? Look:
FOGAÇA, Jennifer Rocha Vargas. "How stainless soap works"; Brazil School. Available in: https://brasilescola.uol.com.br/quimica/como-funciona-sabonete-inox.htm. Accessed on June 28, 2021.
Chemistry
Atmospheric corrosion resistant steel, Chrome, Nickel, manufactured from pig iron in blast furnaces, resistance to high temperature oxidation, Stainless steel, group of ferrous alloys resistant to oxidation and corrosion, production of parts for vehicle
