Dear Saket Phadkule, my answer is a general comment since no details are supplied about the environment to which DMSO is in contact. DMSO is a very reactive solvent, which means possible chemical changes occur upon contact with other sources such as compounds with reactive hydrogen, metals, halogens .... The most unpleasant problem is that it is a solvent that may generate peroxides under known conditions. Peroxides in spite of their toxicity, they are extremely reactive, may provoke a runaway and violently reaction. So, if it is to be reused, one may expect surprises. Page 8 in the attached document shed light on some features. My Regards

If it is dry it should be fine, as under most circumstances (not in the presence of strong base) it is very stable, and 45C isn't too hot. If it is impure and bases are present oxidation to dimethylsulfone can occur. If the atmosphere it is exposed to is inert e.g., nitrogen etc and oxygen free. oxidation will not occur