Yeah, I also go by the petroleum distillates content. If it contains it, I'd say the dressing is not water based, and therefore is not a PDMS dressing like we try to use. PDMSs also look milky white in appearance. You can also usually open up these bottles and take a peek and whiff.
I'd be wary of clear dressings with pet. distillates, but I'm not sure any modern water based dressing would contain so-called "bad" silicones anymore.... Personally, I don't sweat it and just stay away from the pet. distillates and the clear stuff. BTW, PDMS is a "silicone", just not one we should worry about.