If you picked up any anti-aging serum and examined the active ingredients, chances are “glycolic acid” would be the top of the list. Glycolic acid has enjoyed cult-like status among skincare formulators for decades for its unique skin resurfacing abilities and eco-friendly footprint. But glycolic acid has a surprising secondary market: industrial and household cleaning.
This tiny-but-mighty organic acid is the backbone of the world’s most successful concrete removers, boiler cleaners, and dairy farm tank cleaners. If you’re an avid glycolic skin peel user, don’t fret: the properties that make glycolic acid such an effective exfoliator happens to be beneficial in these other markets as well. The main point of difference with glycolic acid are its small size, strong acid properties, affinity for chelating calcium, and natural biodegradability.
Glycolic Acid Is A Small Molecule
Glycolic acid is the smallest alpha-hydroxy carboxylic acid. It has a backbone of just two carbons, and two active functional groups packed into this small space. Its diminutive size enables the molecule to enter spaces that are much too tight for larger cleaning compounds, such as nonionic surfactants or larger organic acids like phosphoric acid. This is well-suited in a concrete remover formulation, especially for tools or trucks that have small or inaccessible moving parts. Concrete removers that are formulated with a 70% solution of glycolic acid and a cosolvent such as glycol ether DPM can penetrate the small gaps and dissolve residual hardened concrete, without the need for scrubbing.
Strong Acid Properties
How does glycolic acid dissolve concrete so efficiently? The answer lies in the electron-withdrawing power of the alpha hydroxy group. Traditional organic acids are categorized as “weak” acids: since they will not completely release their acidic proton, they have poorer reactivity with compounds that need to be cleaned away, such as concrete residue or metal oxides (rust). When a hydroxyl group is introduced in the alpha position, a hydrogen bond is formed with the carboxyl oxygen atoms and occupies all bonding electrons, thus popping off the acidic proton easily. As a stronger acid, glycolic acid is much more active in reactions with concrete and metal oxide residues to clean them away. It is safe for use on a variety of industrial metals without risk of volume loss, such as stainless steel, aluminum, copper, and bronze.
Calcium Chelating For Dairy Farm Cleaning
Glycolic acid forms particularly strong complexes with copper and lead metal ions, which leads to marvelous utility in the dairy industry. Milk tankers, which are generally stainless steel, are subject to stringent sanitation requirement by the FDA (Food and Drug Administration). The most difficult residue to clean off is the milk protein casein, which has a very high affinity for binding copper (II). By complexing the copper (II) in casein, glycolic acid will quickly remove all residue.
Up until recently, the acid cleaner of choice for metal tankers and industrial boilers was hydrochloric acid (HCl). HCl is also a very small, very strong acid. It is a remarkably efficient metal oxide remover – sometimes too efficient, as volume loss is a significant risk. Its primary drawback, however, is the chloride content. Safe administration and cleanup of chloride-containing compounds is complicated and expensive. Glycolic acid is a natural alternative, completely biodegradable, and so nontoxic to humans that it is used in dermal cosmetics. In today’s eco-conscious cleaning market, switching from a toxic formula to a natural one with almost the same cleaning power is a no-brainer. In some industries (like dairy), a food-safe cleaner is a must.
Silver Fern Chemical is currently the leading importer of glycolic acid for industrial use. Most glycolic acid globally is manufactured in the Asia/Pacific region, and we have utilized our international vendor relationships to bring these economies of scale to our customers stateside. If you’re interested in learning more about whether glycolic acid would work for your cleaning formula or download glycolic acid sds (Safety Data Sheet), please reach out to us and we will be happy to help.