Dimethyl sulfoxide, or DMSO, has low toxicity in humans. Solutions with concentrations up to 70 percent may be applied to the skin safely, and solutions with up to 50 percent concentration may be applied to the eye, according to the National Institutes of Health's TOXNET.
DMSO is a colorless, odorless liquid used in topical pharmaceuticals for its skin-permeating properties, says TOXNET. It is approved in the United States for osteoarthritis pain treatment. Contact exposure to DMSO most often results in skin irritation and a garlic-like body odor. Overexposure may induce nausea, headache and light sensitivity. DMSO presents a low ingestion hazard, but ingestion still requires immediate medical attention, according to Gaylord Chemical's material safety data sheet. In certain sensitive individuals, 10-percent DMSO solutions may cause skin reactions.