Not enough info, the brand would help a lot more. Most vodkas will have a slightly thicker consistency once they’ve been in a freezer over an hour, some (the cheaper brands) will pour with ice particles clogging the neck, really cheap bottles (or ones in a freezer which is colder than usual) will freeze solid.
If it’s a regular vodka the alcohol content should keep it free from any nastiness, although no vodka has lasted more than a few months in my house.
I prefer half-finished. I guess that makes me a Terry Tipler.