Dimethyl sulfoxide (DMSO) is a chemical compound which is a by-product of wood processing. It is a somewhat oily liquid that looks like mineral oil and has a slightly garlicky odor. It has long been used as a chemical solvent. In the late 1960s, it also became popular as a topical pain relief medication for pulled, strained, and sprained muscles and joints.
May cause skin irritation. Avoid contact with eyes, skin, clothing. Wash thoroughly after handling. In case of contact, immediately flush eyes with water. Call a physician.
Note: Pure DMSO crystallizes at temperatures below 67 F. This does not harm the product. Thaw in a warm place. Keep away from open flames.