The 8 fl oz unopened bottle of 99.995% pure pharma grade DMSO sold by DMSOstore.com on Amazon, that I put inside a 40 degree F fridge, completely froze with no water seen anywhere inside the bottle. It did take overnight for that to happen, however.
On the bottle label is says the bottle contains only DMSO without additives or water. That means it is not diluted with water; it contains 100% DMSO. Often, you will want to use 70% DMSO plus 30% water dilution. I make bottles with no dilution, 70% and 50% diluted.