Medicine. Refers to something used on or applied to the skin. Transdermal refers to something (such as a medication or drug) being delivered through the skin. You may be familiar with transdermal nicotine or motion sickness patches which are applied to the skin. Additional Info: Some chemicals can move through the skin very easily and can carry toxiccompounds along with them that would not ordinarily penetrate the skin by themselves. One such example is dimethyl sulfoxide (DMSO), a common industrial solvent. Always use extreme care around liquids and wear proper gloves for the solvents you are working with. Many chemicals can cause conditions such as dermatitis when they contact the skin. These effects can by chronic or acute depending on the nature of the chemical and the exposure. See: Our entry on cutaneous for additional information. MSDS Relevance: When you See: This word on an MSDS, it is usually describing a possible result of getting the material on your skin. Therefore, be sure to use proper skin protection such as gloves or an apron. The skin is the largest organ of your body. If your body is splashed with ahazardous chemical, it is important to immediately rinse it off, removing affected clothing if necessary. Your workplace should have either drench hoses or an emergency safety shower if you are working with chemicals that can damage the skin. This is especially true for corrosives such as acids and bases or chemicals which readily penetrate the skin such as hydrofluoric acid and phenols. See also: Cutaneous, Dermal Toxicity, Dermatitis, PPE