Review on 👌 High-Quality Kosher Pure Propylene Glycol Quart - Ideal for Various Applications by Robert Pearson

My usage is probably not typical. I have a floor drain with a siphon. The siphon is a U-shaped bend in the drain line. The liquid in the water trap prevents sewer gas from entering the house on the other side of the water trap. If water does not enter the sewer system for several weeks, the water will evaporate to a level sufficient for gases to pass through. So I have to fill the trap with a liquid that won't evaporate. A readily available liquid with a very low evaporation rate is automotive antifreeze such as ethylene glycol. However, when the water eventually ends up down the drain, the antifreeze will be flushed down the drain. Since ethylene glycol is toxic, I use non-toxic, low evaporation rate propylene glycol instead.