The CO2 itself should be harmless, but I would be a bit uncertain about the potential for other gases in the extinguisher. If it is not pure, then there’s a chance that it can cause additional problems. Leaving aside the composition of extinguishers (which should be closely matched to pure), they come out at high pressure. This could cause problems with other goods, for example, dislodging them and throwing them on the food. Carbon dioxide is not harmful and doesn't leave any residue. Overall, I’d be fairly confident that it’s safe.