Absolutely. I can't find the source, but I remember reading somewhere that the beverage companies put together a "CO2 Purity Requirements" thing, and it turned out industrial CO2 was already way more pure. Surprise!
The purity in gasses mostly refers to the presence of water vapour or machine oils. A great example of machine oil presence is in cheap nitrous canisters. Easy to see, just go find someone hitting the hippie crack at a party, wait till they finish a hit and ask to have a geez at their Bulbinator. Unscrew that bad boy and wipe your finger around the inside of the canister. Will 9 out of 10 times come out with oil residue on it. Nasty shit.