Ask A Scientist: Smellovision

Unprofessional Cookery

Question: “Does stainless steel really remove lingering smells from your hands?” -David C  Queens, NY

Answer:  Officially speaking, the answer is “we’re not really sure”.  Anectdotal evidence says that to remove the piquant bouquet from those Texas 1015′s and elephant garlic that all you need to do is wash your hands with some stainless steel, but there’s not really any hard scientific evidence as if this really works or not.  However, there are a few ideas on the subject.

Before we delve into how to remove the aroma that adheres so ardently to your hands, it might be nice to know what is causing all the stink.  (Sorry, I couldn’t resist.)  Onions and garlic, members of the allium genus, contains amino acids within its cell walls that are released when the onion is cut and handled.  These amino acids combine with the air to form sulfuric compounds that both irritate your eyes( in the case of onions) and readily adhere to your skin (otherwise).  I could geek out more about this, but for the sake of the argument all we really need to know about this is that sulfuric compounds are what’s sticking to your hands.

Next, lets see what makes stainless steel so unremarkable.  (God, I am full of them tonight!)  Stainless steel is a composite material made from steel alloy and chromium.  The chromium in the composite prevents the rust through a process known as passivation, as it bonds with oxygen to form a self renewing protective layer.  Stainless steel, although it is remarkably hard and oftentimes shiny, is also somewhat porous, surprisingly.

Anyways, now that we know what causes your hands to stink and what your sink is made out of, the next is why these two may or may not play well together.

There are two possible ways that stainless steel removes odors from the hands, through either a physical change or a chemical one.  As noted earlier, stainless steel is a porous material, containing many little crevices along its surface.  Your skin, much like that steel, is also porous and has many little crevices along its surface.  All those little crevices are just perfect for sulfuric compounds to hang out in.  Thus, if you think of it in the terms of agitation and transference, if you rub one porous surface against another in ideal conditions (like under running water), those particularly pervasive compounds simply move from one surface to another.

If this is the case, then just about anything porous might work to remove kitchen stink.  Plastic containers, rubber spatulas, wooden spoons- the possiblities for stink transactions are endless!  Whooee!

The second possibility is that stainless steel works as a catalyst in breaking down sulfuric compounds.  Lets revisit that idea of your skin being porous for a second.  In addition to the sulfuric compounds just resting in the crevices of your skin, they could also be clinging to your skin because these sulfuric compounds bond with the oils that you produce naturally.  Now, lets say that you were going to wash your hands after cutting an onion, as you probably would do anyways.   If the latter statment about oil binding is true, the water may help break up some of those bonds without having to do much.

So!  The stainless steel, in theory, would just facilitate these chemicals breaking down faster by perhaps bringing those sulfuric compounds to the surface of your skin faster.  From there the compounds wound suffer a merciless pogrom from your kitchen faucet!  (This hypothesis may be a stretch to prove, but I’m running with it.)

Or, it could also be a combination of both of these explanations.  Either way, don’t bother investing in one of those stainless steel nubs, as just about anything stainless steel would work.  Even a fork.