A year ago when I brought my truck in for its annual inspection I had asked the manager at the garage about replacing my coolant with propylene glycol instead of the traditional ethylene glycol based fluids. He had told me that no, it wasn't possible due to fluid disposal issues they had. I suggested to him that it would be great if they considered offering this choice... that pet lovers and the pro-green folks would go for it.

Well here is a year later, and when I dropped off my truck at the same place for inspection and tuneup, lo and behold there was a sign for a coolant change to a propylene glycol based coolant! I was amazed! Such a great coincidence and perfect timing. Of course I had the old coolant flushed out and the ecologoically safer material put in.

Antifreeze (ethylene glycol) is the most common winter poison danger, and can be fatal to companion animals, wildlife, and even children --  especially in the cold north but possible anywhere. I lost a cat to antifreeze ingestion when I lived in Florida.  Ethylene glycol has a sweet taste some dogs and cats can smell at a distance and will actively seek out. A tiny amount can be fatal -- less than two ounces is enough to kill a dog, one teaspoon enough to kill a cat, and as little as two tablespoons can be hazardous to a small child. Most companion animals -- and wildlife -- will rapidly drink many times the fatal dose.

The Humane Society of the U.S. advocates "Better yet, use antifreeze-coolant made with propylene glycol; if swallowed in small amounts, it will not hurt pets, wildlife, or people."

True propylene glycol isn't a perfect substance and can be problematic in large quantities, but it is much safer than ethylene glycol. As long as we drive vehicles that require coolant, we should at least try to have the smallest impact on our environment and other living beings around us.  Check out this Sierra Antifreeze/Coolant web site for more information.