Safety Data Sheets

Trade Name The trademark name or commercial trade name for a material or product. Transplacental Through the placenta. When noted on an SDS, the chemical could pass through the placental barrier to cause harm to the developing fetus. Trauma An injury or wound brought about by an outside force. Tremor Involuntary shaking, trembling, or quivering. TSCA Toxic Substances Control Act (Federal Environmental Legislation administered by EPA) regulates the manufacture, handling and use of materials classified as “toxic substances.” Tumor Abnormal mass of tissue that may or may not be malignant. TWA Time-Weighted Average exposure is the airborne concentration of a material to which a person is exposed, averaged over the total exposure time--generally the total workday (8 to 12 hours). Also see TLV. UEL, or UFL Upper explosive limit or upper flammable limit of a vapor or gas; the highest concentration (highest percentage of the substance in air) that will produce a flash of fire when an ignition source (heat, arc or flame) is present. At higher concentrations, the mixture is too “rich” to burn. Also see “LEL.” ug Microgram, one-millionth of a gram. Ulcer The destruction of an area of skin or mucous membrane. Ulceration The formation or development of an ulcer. Ultraviolet Radiation (Light) Electromagnetic radiation with wavelengths shorter than those of visible radiation and longer than those of x-rays; wavelengths 10 -5 cm to 10 -6 cm. Unstable Tending toward decomposition or other unwanted chemical change during normal handling or storage. Unstable Reactive A chemical that, in the pure state, or as produced or transported, will vigorously polymerize, decompose, condense or become self-reactive under conditions of shocks, pressure, or temperature. Urticaria Hives. USDA U.S. Department of Agriculture.