Knowledge

The History of Coolants

The first engine coolant was invented in 1929 by BASF under the brand Glysantin, marking a significant advancement in vehicle maintenance. Before coolant, engines were almost exclusively cooled by water, which required draining before cold nights to prevent freezing and damage to the cooling system. In the mid-1920s, BASF's director asked Dr. Otto Jordan to develop an antifreeze solution that would protect the increasingly complex engine cooling systems in use.

Interactive Timeline of Coolant Evolution

• 1929: Introduction of Glysantin (BASF)
• Mid-20th Century: Transition from pure water to glycols and IAT coolants
• 1980s-1990s: Development of OAT, HOAT, and long-life coolants
• 2010s-Onward: Rise of EV coolants and eco-friendly formulations

Why Is Coolant Important?

Whether your goal is lowering fuel costs or reducing emissions, maintaining your vehicle's cooling system is crucial to reaching those objectives. Coolant plays a critical role in:

• Heat Regulation: Transfers heat away from your engine, maintaining optimal temperatures for peak performance.
• Protection Against Corrosion and Scaling: Shields the cooling system from corrosion and scaling that could lead to long-term damage.
• Longevity and Consistency: By preventing corrosion, coolant helps maintain consistent vehicle performance, letting you drive longer with fewer repairs.

Low-quality coolant can cause your cooling system to rust, leading to engine overheating—risks that not only threaten road safety but could also mean costly repairs.

What Is Antifreeze?

Antifreeze, or engine coolant, is a liquid formulated with water and chemicals like ethylene glycol to maintain stable engine temperatures in extreme weather conditions. By mixing antifreeze and water (usually at a 50/50 ratio), your engine can handle both high and low temperatures. Ethylene glycol, the primary ingredient in most coolants, lowers the freezing point and raises the boiling point of the coolant mixture, which helps in regulating the engine's operating temperature.

Regardless of the coolant color (green, pink, or orange), they share the same ethylene glycol base. It’s essential to check your coolant levels regularly, at least twice a year—ideally before summer and winter—to ensure optimal performance and avoid overheating or freezing. Consult your vehicle's manual for specifics on when to replace or flush the coolant.

Coolant Colors

The color of the coolant is simply a dye and does not indicate the coolant type or quality. Coolants are generally labeled as Type “A” or Type “B”.

Types of Engine Coolants

Coolants come in various formulations, each with specific properties suited for different engine needs. Below are the main types of coolants and additives:

1. Ethylene Glycol: Lowers the freezing point and is commonly used in coolants.
2. Propylene Glycol: Less toxic than ethylene glycol but slightly less effective in lowering freezing points.
3. Organic Acid Technology (OAT): Long-lasting, corrosion-resistant coolants that rely on carboxylate technology.
4. Inorganic Additive Technology (IAT): Conventional coolant with ethylene glycol, requiring more frequent replacement.
5. Hybrid Additive Technology (HOAT): Combines conventional inhibitors and organic salts for broader compatibility and extended life.
6. Conventional Coolants: Often include silicates and may have extended additives to enhance lifespan.

Common Coolant Additives

Engine coolants often contain additional compounds to improve performance:

• Organic Acids
• Silicates and Phosphates
• Nitrites
• Defoamers
• Bittering Agents
• Borates

Key Characteristics of Coolants

OAT Coolant

• Low Inhibitor Depletion: Long-life, "fill for life" coolant.
• Temperature Stability: Performs well in high-temperature conditions.
• Heat Transfer: Ensures efficient heat dissipation.

Hybrid Coolant

• Corrosion Protection: Nitrites create a protective layer to prevent cavitation and scaling.
• High Reliability: Proven effectiveness in diverse cooling system designs.
• Extended Change Intervals: Requires less frequent replacement.

Ethylene Glycol (MEG) Content

An ideal coolant mixture contains between 33% and 50% ethylene glycol for optimal performance:

Understanding Coolant Colors

Coolant colors (green, blue, orange, red) traditionally indicate specific types but are not reliable indicators of coolant formulation. Follow your vehicle manufacturer’s recommendations when selecting a coolant to ensure compatibility.

• Green & Blue: Commonly used in IAT coolants, these colors are often found in older vehicles and need changing every two years.
• Orange & Red: Extended Life Coolants (ELC), offering intervals of up to seven years or 300,000 km, thanks to added corrosion inhibitors.
• Other Colors: Yellow, purple, pink, and turquoise may represent different chemical compounds, like HOAT phosphate coolant, but color alone does not define coolant composition.

Mixing Different Coolant Colors

Mixing coolants of different colors is generally discouraged since they contain unique additives and inhibitors that can react negatively when combined. If needed, drain the existing coolant completely before refilling with a different type.

Coolant in Electric Vehicles (EVs)

With the rise of electric vehicles, OEMs face the challenge of keeping batteries cool to maintain performance, charging speed, and lifespan. Initially, EV batteries were air-cooled, but modern electric vehicles use liquid cooling systems with a mixture of glycol and water, similar to internal combustion engines.

Key Characteristics of EV Coolants

1. Thermal Conductivity: Efficient heat transfer to keep batteries at optimal temperatures.
2. Electrical Insulation: High dielectric strength to prevent electrical shorts.
3. Low Freezing Point: Essential for colder climates.
4. Anti-Corrosion: Protects sensitive EV components over time.
5. Eco-Friendly and Durable: Designed to be long-lasting and environmentally responsible.

Environmental Impact & Recycling of Coolants

Coolants play an essential role in vehicle operation, but their environmental impact is significant, especially if they’re not disposed of or recycled properly. Traditional engine coolants like ethylene glycol can be toxic to both humans and wildlife, making responsible coolant management crucial.

Waste antifreeze may contain heavy metals such as lead, cadmium, and chromium in high enough levels to make it a regulated hazardous waste. Hazardous waste may never be dumped on land or discharged into a sanitary sewer, storm drain, ditch, dry well, or septic system.

Environmental Concerns with Coolants

1. Toxicity to Wildlife
   Ethylene glycol, the primary ingredient in many coolants, is toxic to animals and aquatic life. It has a sweet taste, which can attract animals if spilled or improperly disposed of, leading to accidental ingestion and fatal poisoning.
2. Soil and Water Contamination
   Improper disposal can contaminate groundwater and soil. Toxic compounds from used coolants can leach into surrounding environments, where they persist and accumulate, potentially impacting local ecosystems and drinking water supplies.
3. Air Quality and VOC Emissions
   Some coolants contain volatile organic compounds (VOCs), which can evaporate and contribute to air pollution. VOCs react with nitrogen oxides in sunlight to create ground-level ozone, a major component of smog.
4. Carbon Footprint and Production Impact
   The production of ethylene glycol and propylene glycol involves energy-intensive processes that contribute to CO₂ emissions. Alternative, eco-friendly coolants with bio-based additives are emerging, but adoption is still limited

Recycling and Disposal of Coolants

With a growing focus on sustainable practices, recycling and safely disposing of coolants is essential:

1. Coolant Recycling Process
   Recycling facilities process used coolant through filtration, distillation, and chemical treatments. This process removes contaminants like heavy metals, acids, and glycol breakdown products, making it safe for reuse. Recycled coolants can meet or exceed the performance standards of new coolants, reducing waste.
2. Glycol Recovery and Reuse
   Glycol, the active component in many coolants, can be recovered from used coolants and purified for reuse. This reduces demand for new glycol production, cutting back on both resource extraction and environmental emissions.
3. Safe Disposal Practices
   When recycling isn’t an option, proper disposal is critical:

• Licensed Facilities: Take used coolant to a licensed disposal or recycling facility. Many automotive repair shops, recycling centers, and waste disposal facilities accept used coolant.
• Never Dispose of Coolant in Drains or on the Ground: Pouring coolant into sewers, drains, or soil can lead to contamination of waterways and groundwater, impacting ecosystems and human health.

More on Modern Additive Technologies

• Glycerin-Based Coolants: Glycerin is a less toxic alternative to ethylene glycol and has recently gained traction as a safer, eco-friendly coolant.
• Advanced HOAT and POAT Coolants: Including details on Phosphate Organic Acid Technology (POAT), used in Japanese and Asian markets, and other hybrid formulations that combine silicates or phosphates with OAT to extend lifespan and compatibility.