Which type of coolant is not poisonous?

Which type of coolant is not poisonous?

• A. Ethylene glycol based
• B. Propylene glycol based
• C. Alcohol based
• D. Water only

Answer: (B)

The important point is safety and toxicity differences among common coolant chemistries. Ethylene glycol–based coolant is highly poisonous if ingested and is a major health hazard to people and pets. Alcohol-based coolant also poses health risks and is flammable. Water by itself isn’t a practical coolant because it lacks the additives that prevent freezing, boiling, and corrosion inside the engine, so it isn’t used as a stand-alone coolant. Propylene glycol–based coolant is designed to be much less toxic than ethylene glycol, offering a safer profile while still providing the necessary protection for the cooling system. That combination of reduced toxicity and effective cooling protection makes it the best choice in this context.

The important point is safety and toxicity differences among common coolant chemistries. Ethylene glycol–based coolant is highly poisonous if ingested and is a major health hazard to people and pets. Alcohol-based coolant also poses health risks and is flammable. Water by itself isn’t a practical coolant because it lacks the additives that prevent freezing, boiling, and corrosion inside the engine, so it isn’t used as a stand-alone coolant. Propylene glycol–based coolant is designed to be much less toxic than ethylene glycol, offering a safer profile while still providing the necessary protection for the cooling system. That combination of reduced toxicity and effective cooling protection makes it the best choice in this context.