It outperforms citric and acetic acids at dissolving stubborn grout and concrete residues, and it does so with dramatically less metal corrosion than HCl or phosphoric acid.

Glycolic Acid Tech 70% from PureTech Scientific is a 70% glycolic acid solution manufactured in Belle, WV. It’s the only domestically produced glycolic acid in North America, with reliable supply and consistent quality.

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How Does Glycolic Acid Dissolve Concrete?

Concrete’s structure is held together by calcium compounds, primarily calcium silicate hydrate (C-S-H) and calcium hydroxide (portlandite). When glycolic acid contacts hardened concrete, it reacts with these calcium compounds to form calcium glycolate, a water-soluble salt. That reaction breaks down the binding matrix and releases the aggregate (sand and gravel), which can then be rinsed or pressure-washed away.

What sets glycolic acid apart from other organic acids is the electron-withdrawing power of its alpha-hydroxy group. Traditional organic acids like citric and acetic acid are "weak" acids that don’t fully release their acidic proton, which limits how aggressively they react with calcium carbonate and calcium hydroxide. Glycolic acid’s alpha-hydroxy group pulls electron density away from the carboxyl group, making it a stronger acid with better reactivity against concrete’s calcium compounds.

Its small molecular size adds a second advantage. Glycolic acid penetrates into the pores and microcracks of hardened concrete, reacting with calcium from within the residue rather than only working the exposed surface. Larger molecules like phosphoric acid and nonionic surfactants can’t get into those tight spaces. When paired with a cosolvent like glycol ether DPM, glycolic acid formulations dissolve hardened concrete from tools, trucks, scaffolding, and equipment without scrubbing.

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Why Use Glycolic Acid Instead of HCl for Concrete Removal?

Muriatic acid (hydrochloric acid / HCl) has been the default choice for concrete removal in construction for decades. It’s cheap and fast-acting, but the trade-offs are real: it’s highly corrosive to metal equipment, it produces strong fumes, and the chloride content complicates disposal. On jobsites with painted surfaces, aluminum scaffolding, or enclosed spaces, HCl creates problems that glycolic acid avoids entirely.

Glycolic acid is nonflammable, has negligible odor and very low vapor pressure, and contains no chlorides. It’s biodegradable, low in toxicity, and safe enough to handle without the extensive PPE that HCl demands. For contractors and fleet operators cleaning concrete off trucks, mixers, and tools daily, those handling advantages compound quickly.

The corrosion difference tells the story clearly. In 48-hour immersion testing at 23°C, glycolic acid caused just 0.17% weight loss on 1018 carbon steel. Phosphoric acid caused 0.64%. HCl caused 2.03%, roughly 12 times more metal loss than glycolic acid. On aluminum, the gap is even wider: glycolic acid showed 0.009% weight loss compared to 1.39% for phosphoric acid.

Corrosion Rate: Glycolic Acid vs. Phosphoric Acid vs. HCl

Percent weight loss at 23°C (73°F), 48-hour immersion, no agitation

_{*HCl dissolved the aluminum sample completely before the 48-hour mark, so no weight loss percentage could be recorded.}

On stainless steel (304 and 316), glycolic acid and phosphoric acid both show near-zero corrosion. But HCl caused 0.53% loss on 304 and 0.94% on 316, which matters for stainless-lined equipment and mixing vessels. For any application where equipment longevity, worker safety, or disposal simplicity matters, glycolic acid is the stronger choice.

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How Does Glycolic Acid Compare to Other Acids for Concrete Cleaning?

vs. Hydrochloric Acid (HCl / Muriatic Acid): HCl reacts faster but causes 12x more corrosion on carbon steel and destroys aluminum. It produces dangerous fumes, contains chlorides that complicate disposal, and risks etching metal surfaces. Glycolic acid matches HCl’s concrete dissolution at practical contact times (30+ minutes) with dramatically less equipment damage.

vs. Phosphoric Acid: Phosphoric acid is commonly used for concrete etching and cleaning, but it’s far more aggressive on aluminum (1.39% vs. 0.009% weight loss) and nearly 4x more corrosive on carbon steel. Phosphoric acid’s larger molecular size also limits its ability to penetrate hardened concrete pores.

vs. Citric Acid: Citric acid is milder and biodegradable, but it’s a weaker acid with poorer reactivity against calcium compounds. It struggles with heavily cured concrete and thick cement residues.

vs. Acetic Acid (Vinegar-Based Products): Acetic acid is too weak for industrial concrete removal. Consumer-grade vinegar runs 3–5% acidity, and even cleaning-grade vinegar at 8% can’t handle hardened cement.

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Concrete Cleaner and Remover Starter Formulations

The following formulations provide starting points for glycolic acid-based concrete cleaners. Both use a nonionic alcohol ethoxylate surfactant for wetting and a glycol ether cosolvent to boost penetration into hardened concrete.

Standard Concrete Cleaner Formulation

Standard Concentrate		Standard Ready-To-Use (Diluted)		Ingredient Examples
Glycolic Acid, 70% Tech Grade	80.0%	Glycolic Acid, 70% Tech Grade	20.0%	PureTech Scientific Glycolic Acid, 70% Tech Grade
Nonionic alcohol ethoxylate surfactant	4.0%	Nonionic alcohol ethoxylate surfactant	1.0%	Tergitol 15-S-9 (Dow)
DPM Glycol Ether	16.0%	DPM Glycol Ether	4.0%	Dowanol DPM (Dow)
Water	0.0%	Water	75.0	Water

Low/No Corrosion Concrete Cleaner Formulation

This formulation adds a corrosion inhibitor for applications where the cleaner will contact sensitive metal surfaces for extended periods.
 

Low/ No Corrosion Concentrate		Low/ No Corrosion Ready-To-Use (Diluted)		Ingredient Examples
Glycolic Acid, 70% Tech Grade	76.0%	Glycolic Acid, 70% Tech Grade	20.0%	PureTech Scientific Glycolic Acid, 70% Tech Grade
Nonionic alcohol ethoxylate surfactant	4.0%	Nonionic alcohol ethoxylate surfactant	1.0%	Tergitol 15-S-9 (Dow)
DPM Glycol Ether	12.0%	DPM Glycol Ether	4.0%	Dowanol DPM (Dow)
Corrosion Inhibitor	8.0%	Corrosion Inhibitor	2.0%	Rodine 103
Water	0.0%	Water	73.0%	Water

How to Use Glycolic Acid Concrete Cleaners

These instructions apply to the ready-to-use (diluted) formulations above.

1. Dilute with tap water before use 1:4 (For ready-to-use formulations only).

2. Spray the solution onto the surface or substrate where concrete needs to be removed.

3. Allow at least 30 minutes of contact time (For heavy buildup, leaving the solution to react overnight or between shifts is acceptable).

4. Power-wash the equipment and parts to remove the dissolved concrete residue.

5. For extremely heavy residuals, a second treatment may be needed

Wear appropriate personal protection equipment. As with all acids, do not spray on hot surfaces.

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Where Glycolic Acid Concrete Cleaners Are Used

Glycolic acid-based concrete cleaners serve a range of construction, industrial, and fleet maintenance applications. Concrete truck and mixer washout is one of the most common uses: glycolic acid dissolves hardened cement from drums, chutes, and hoppers without damaging the metal underneath. Tool and equipment cleaning is another natural fit, especially for small parts, scaffolding hardware, and forming equipment where concrete builds up in tight joints and moving parts that larger acid molecules can’t reach.

Masonry surface cleaning is the third major application. Glycolic acid removes cement haze, grout residue, efflorescence, and mineral deposits from brick, block, and stone surfaces. Its low corrosivity means it won’t etch or discolor most substrates the way HCl can. Fleet operators also use glycolic acid cleaners to remove concrete splatter from truck bodies, undercarriages, and painted surfaces without stripping paint or corroding metal.

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Why Formulators Choose Glycolic Acid for Concrete Cleaning Products

Glycolic acid brings a combination of performance and practical advantages that other acids can’t match in a single product. It penetrates and loosens hardened concrete with strong calcium complexing and efficient mineral dissolution, while its low corrosion profile protects metal equipment, coatings, and painted surfaces. It sequesters hard water salts including calcium, magnesium, and metasilicates, and it rinses clean with minimal residue on the substrate.

From a formulation standpoint, glycolic acid is highly water-soluble and readily dilutable to any target concentration. It’s compatible with other acids for blended formulations, and it works well with standard cosolvents and surfactants. It’s biodegradable, nonflammable, low in toxicity, has negligible odor, and is VOC exempt in California. Those handling and environmental properties simplify safety compliance, disposal, and jobsite logistics for the end user.

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Frequently Asked Questions

What acid dissolves concrete without damaging metal?
Glycolic acid dissolves hardened concrete by reacting with calcium compounds to form water-soluble calcium glycolate. In corrosion testing, it caused just 0.17% weight loss on carbon steel at 23°C over 48 hours, compared to 2.03% for HCl. It’s safe on stainless steel, aluminum, copper, and most coated surfaces.

Is glycolic acid better than muriatic acid for concrete removal?
For most equipment and surface cleaning applications, yes. Glycolic acid matches HCl’s cleaning performance at practical contact times while causing roughly one-twelfth the corrosion to carbon steel. It also eliminates the chloride risk, strong fumes, and disposal complications that come with muriatic acid.

How long does glycolic acid take to dissolve concrete?
Contact time depends on the thickness and age of the concrete residue. For light to moderate buildup, 30 minutes of contact followed by pressure washing is usually enough. Heavy residuals may need an overnight soak or a second treatment.

Can you use glycolic acid on painted surfaces?
Glycolic acid’s low corrosivity makes it safe on most painted surfaces and coatings when used as directed. It won’t etch or strip paint the way HCl or muriatic acid can. As with any acid cleaner, testing on an inconspicuous area first is good practice.

What concentration of glycolic acid is used in concrete cleaners?
Starter formulations typically use Glycolic Acid Tech 70% as the active ingredient, diluted with water and cosolvents to the target use concentration. A common ready-to-use dilution is 1:4 with tap water, resulting in approximately 14% glycolic acid at point of use.

Is glycolic acid biodegradable?
Yes. Glycolic acid is readily biodegradable, nonflammable, and low in toxicity. It contains no phosphates or chlorides, which simplifies disposal and reduces environmental impact compared to mineral acids like HCl and phosphoric acid.