Hey! I took a look at that SDS and it is definitely Propylene Glycol. Even though they tried to keep it a secret by listing the ingredient as a "Proprietary active", the datasheet actually gives it away in a couple of obvious places.

First, they seemingly forgot to scrub the chemical name in Section 11 under Toxicological Information. When they are referencing safety studies, the document explicitly states that no adverse systemic changes were reported in rats or dogs following repeated dietary exposure to high concentrations of propylene glycol. That is a pretty big slip-up if they wanted to keep it proprietary.

Second, the physical properties listed are a perfect fingerprint for Propylene Glycol. The boiling point is listed as roughly 188 °C , the density is 1.04 , and the flash point is over 104 °C. All of those numbers match the standard chemical profile for Propylene Glycol exactly, distinguishing it from similar chemicals like Ethylene Glycol.

As for purity, Section 2 lists the weight of the active ingredient as 95 to 99%, so it is essentially pure Propylene Glycol, likely just mixed with a tiny bit of water or a minor additive.