Iron X does an amazing job of removing orange spots (rail dust, industrial fallout, etc.). But, that smell! What is it about Iron X that makes it smell so bad?
Why does Iron X smell so bad? Iron X is made up of 25-30% Ammonium mercaptoacetate which works very well to remove orange spots, it is also the source of the nasty odor. Mercaptans are notorious for their odor, which is why mercaptans are added to natural gas in order to detect leaks.
Ammonium mercaptoacetate: This chemical is likely the source of the bad smell. The second part of the chemical name begins with mercapt… This material is a mercaptan, which is the source of the “rotten egg” odor of Iron X. Mercaptans have this distinct “rotten egg” odor and are products of decomposition of organic material. Mercaptans are added to propane and natural gas so that we can smell leaks in these systems.
Not only is ammonium mercaptoacetate the source of the odor, it is also the source of the nasty hazard classes listed on the SDS. The Iron X SDS lists the following hazards for Ammonium mercaptoacetate (Hazard codes are listed next to each chemical hazard):
Metal Corrosive 1, (H290 May be corrosive to metals.)
Acute Toxicity 3, (H301 Toxic if swallowed.)
Skin Sensitizer 1, and (H317 May cause an allergic skin reaction.)
Click here to learn more about the hazards of Iron X (and other fall out removers) and how to protect yourself.
Synonyms:
5421-46-5 [RN]
6P9E788VZZ
Acetate, 2-mercapto-, ammonium salt (1:1)
acetic acid, 2-mercapto-, ammonium salt
Ammonium mercaptoacetate
Ammonium sulfanylacetate
AMMONIUM THIOGLYCOLATE
Ammoniumsulfanylacetat
Perm Salt
Identifiers
CAS Number: 5421-46-5
ECHA InfoCard: 100.024.128
PubChem CID: 21534
Properties:
Chemical formula: C2H7NO2S
Molar mass: 109.15 g/mol
The ECHA database lists the following synonyms for Ammonium mercaptoacetate:
Ammonium Thioglycolate 59% (50% TGA)
Ammonium thioglycolate 59% (50% TGA) low odor
Ammonium Thioglycolate 59% (50% TGA) pH 6.4
Ammonium Thioglycolate 70 W (59 – 61 % TGA)
Ammonium Thioglycolate 71% (60% TGA)
Ammonoium thioglycolate 71% (60% TGA low odor
This is important! This paragraph is worth much more than chemical trivia. This is particularly important because different manufacturers of fallout removers may name the chemical differently! For example, I watched a Youtube video where the person was using a fallout remover and he kept referring to “ammonia thio”. Careful, use of different terms does not indicate different chemical in this case.
What’s the source for this information?
This information was hidden in plain sign on the Safety Data Sheet. Why would CarPro share “the secret sauce?” Because all companies have a legal obligation to state the hazardous components of a mixture. Companies can state that an ingredient is “proprietary” or “a trade secret”, but they still need to list the hazards of the proprietary components. Considering that CarPro has not listed any of these ingredients as “proprietary”, there’s a pretty good chance that these hazardous components are included in every fallout remover available on the market.
I know that the cherry scent may make the material it bit more palatable. But, come on….this stuff smells nasty. I don’t see you adding this as a mixer to your favorite cocktail by accident. However, I would recommend that you keep this material out of reach from children and pets.
How is ammonium mercaptoacetate used?
The following information is from the European Chemical Agency website. This is the description provided for Ammonium mercaptoacetate:
This substance is manufactured and/or imported in the European Economic Area in 100 – 1 000 tonnes per year.
This substance is used by consumers, by professional workers (widespread uses), in formulation or re-packing, at industrial sites and in manufacturing.
Consumer Uses
This substance is used in the following products: cosmetics and personal care products, washing & cleaning products, metal surface treatment products and non-metal-surface treatment products.
Other release to the environment of this substance is likely to occur from: indoor use as processing aid and outdoor use as processing aid.
Widespread uses by professional workers
This substance is used in the following products: cosmetics and personal care products, metal surface treatment products, non-metal-surface treatment products and washing & cleaning products. This substance is used in the following areas: formulation of mixtures and/or re-packaging. Other release to the environment of this substance is likely to occur from: indoor use (e.g. machine wash liquids/detergents, automotive care products, paints and coating or adhesives, fragrances and air fresheners) and outdoor use as processing aid.
Formulation or re-packing
This substance is used in the following products: cosmetics and personal care products.
Release to the environment of this substance can occur from industrial use: formulation of mixtures.
Uses at industrial sites
This substance is used in the following products: metal surface treatment products, non-metal-surface treatment products, washing & cleaning products and cosmetics and personal care products.
This substance has an industrial use resulting in manufacture of another substance (use of intermediates).
This substance is used in the following areas: formulation of mixtures and/or re-packaging.
This substance is used for the manufacture of: chemicals.
Release to the environment of this substance can occur from industrial use: as an intermediate step in further manufacturing of another substance (use of intermediates), formulation of mixtures and in processing aids at industrial sites.
Manufacture
Release to the environment of this substance can occur from industrial use: manufacturing of the substance.
Alcohols in the formulation actually reduce the odor! Iron X is also made up of 5 – 10% Alcohols, C10-16, ethoxylated, sulfates, sodium salts
Chemistry
Ammonium thioglycolate, also known as perm salt, is the salt of thioglycolic acid and ammonia. It has the formula HSCH2CO2NH4 and has use in perming hair.
Being the salt of a weak acid and weak base, ammonium thioglycolate exists in solution as an equilibrium mixture of the salt itself as well as thioglycolic acid and ammonia:
HSCH2COO− + NH4+ ⇌ HSCH2COOH + NH3
Thioglycolate, in turn, is able to leave disulfide bonds, capping one side with a hydrogen and forming a new disulfide with the other side:
RSH + R’SSR’ ⇌ R’SH + RSSR’
A solution containing ammonium thioglycolate contains a lot of free ammonia, which swells hair, rendering it permeable. The thioglycolic acid in the perm solution reduces the disulfide cystine bonds in the cortex of the hair. In a sense, the thioglycolate removes crosslinks. After washing, the hair is treated with a mild solution of hydrogen peroxide, which oxidizes the cysteines back to cystine. These new chemical bonds impart the structural rigidity necessary for a successful perm. The rigidification process is akin to the vulcanization of rubber, where commonly polysulfide linkages are used to crosslink the polymer chains. However, not as many disulfide bonds are reformed as there were before the permanent. As a result, the hair is weaker than before the permanent was applied and repeated applications over the same spot may eventually cause strand breakage.
Since polar molecules are less volatile than nonpolar ones, the glycolate substituent makes the thiol non-volatile and hence less odorous. An added advantage is that the glycolate confers some solubility in water.
Source of Chemistry information: Wiki