Yes, there is a small amount of anti-caking agent in it but it
does not affect it's use as a flux.
Generically speaking: If you’re in a chemistry lab and you want
acetone (or borax), you are likely using it to do chemistry - atoms
and molecules bonding together to form new molecules - and any
impurities are going to affect or even destroy the outcome. Those are
the high purity chemicals, and why they are needed.
When you are using acetone to clean a paintbrush or borax on a
casting, just about any old reasonable purity will do - 20 mule team
borax, hardware store acetone, all of which is actually “technical
grade”. In jewelry it’s rare that we need any higher purity than
that. You might buy reagent ammonia or nitric out of convenience or
necessity, but you don’t NEED it like a chem lab does. If you’re
doing something that requires high purity, you’ll probably know it,
and know why, already.