Ethylene Glycol Corrosiveness: Causes, Risks, and Prevention

Ethylene glycol corrosiveness is a major concern in systems that rely on glycol for heat transfer or freeze protection. While pure ethylene glycol is not aggressively corrosive, it can become corrosive when mixed with water, exposed to contaminants, or subjected to heat. This blog explains what increases ethylene glycol corrosiveness, how it affects metals, and what steps can prevent system damage. It also highlights why regular monitoring and proper inhibitor use are essential to maintaining equipment reliability.

Understanding Ethylene Glycol Corrosiveness in Industrial Applications

Ethylene glycol (EG) is a drab, odorless liquid with a candy flavor. Its chemical system is C₂H₆O₂ and it has an excessive boiling point and a low freezing point. Therefore, it is ideal for numerous industrial applications. For example, it is commonly used to prevent freezing and overheating in cooling systems.

Common Uses of Ethylene Glycol

Ethylene glycol is primarily used as an antifreeze in cooling and heating systems. Additionally, it plays a critical role in manufacturing plastics, paints, and cosmetics. Furthermore, its versatility extends to the oil and fuel industry, where it is used as a dehydration agent in herbal gas processing.

Safety Considerations for Ethylene Glycol

While ethylene glycol is undeniably useful, it is equally important to handle it with care. For instance, it is toxic if ingested and may cause severe health issues. As a result, proper storage and handling are essential to ensure employee safety and prevent accidental exposure.

Ethylene Glycol and Corrosion

How Corrosive is Ethylene Glycol?

Ethylene glycol itself is not distinctly corrosive. However, under certain conditions, it may promote corrosion. For example, impurities, water, and high temperatures can enhance its corrosiveness, potentially causing harm to metallic surfaces.

Corrosive Properties of Ethylene Glycol

The corrosiveness of ethylene glycol is largely influenced by its chemical interactions with metals. When mixed with water, it can form acidic byproducts that accelerate corrosion. Moreover, the presence of oxygen and elevated temperatures further exacerbate this effect.

Factors Influencing Ethylene Glycol Corrosiveness

Several factors influence the corrosiveness of ethylene glycol, including concentration, temperature, and the presence of contaminants. Consequently, understanding these elements is crucial for implementing effective measures to mitigate corrosion.

Ethylene Glycol and Metal Corrosion

Impact on Steel and Iron

Ethylene glycol can corrode steel and iron, particularly in systems where the solution is not frequently monitored or maintained. To minimize this impact, corrosion inhibitors can be introduced, which help extend the lifespan of the equipment.

Corrosion of Aluminum by means of Ethylene Glycol

Does ethylene glycol corrode aluminum? Yes, aluminum is vulnerable to corrosion when exposed to ethylene glycol, especially in high-temperature environments. This exposure can lead to pitting and the weakening of aluminum alloys.

Why Ethylene Glycol Corrosiveness Must Be Managed Carefully

Ethylene glycol corrosiveness is an important factor when maintaining coolant systems, heat exchangers, industrial equipment, and other glycol-based applications. When left unchecked, ethylene glycol corrosiveness causes pitting, rust formation, reduced efficiency, and premature equipment failure. Understanding what triggers corrosion—and how to prevent it—ensures safer operations, longer equipment lifespan, and more reliable performance.

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Frequently Asked Questions

1. Does ethylene glycol always cause corrosion?

Ethylene glycol alone is not aggressively corrosive, but ethylene glycol corrosiveness increases when water, oxygen, heat, or contaminants enter the system.

2. What metals are most affected by ethylene glycol corrosiveness?

Steel, iron, aluminum, copper, and brass are vulnerable, especially when inhibitors are depleted or glycol is poorly maintained.

3. How can I reduce ethylene glycol corrosiveness in my system?

Maintaining the proper glycol ratio, monitoring pH, using corrosion inhibitors, and preventing contamination are the most effective strategies.

4. Can degraded glycol be restored?

Degraded glycol may sometimes be filtered or reconditioned, but severe cases require replacement to avoid corrosive damage.

5. What causes ethylene glycol to become more corrosive?

Heat, oxygen exposure, water dilution, impurities, and chemical breakdown all contribute to increased ethylene glycol corrosiveness.

6. How often should glycol be tested?

Most systems benefit from routine testing during scheduled maintenance to track glycol concentration, pH, and inhibitor levels.

7. Is aluminum more sensitive to ethylene glycol corrosiveness?

Yes, aluminum corrodes quickly under acidic glycol conditions, making inhibitor protection crucial.

8. What happens if ethylene glycol corrosiveness is ignored?

Ignoring ethylene glycol corrosiveness leads to leaks, scaling, blocked passages, decreased efficiency, and costly equipment failure.

Key Takeaways

• Ethylene glycol corrosiveness increases when glycol is diluted, contaminated, or overheated.
• Metals such as aluminum, steel, and copper are highly vulnerable to corrosive glycol conditions.
• Regular testing, proper inhibitors, and correct glycol ratios dramatically reduce corrosion risk.
• Early detection of ethylene glycol corrosiveness prevents equipment failure and improves system longevity.
• Engineered solutions from RedRiver LLC support safer, longer-lasting system performance.