Propyl alcohol, 1-propanol (propan-1-ol,IUPAC), is a colorless liquid with an odor similar to ethanol. It is polar, soluble in water, and has a specific gravity of 0.8, which is lighter than water. It is a dangerous fire risk with a flammable range of 2%-13% in air. Vapor density is 2.1, which is heavier than air. Boiling point is 207 °F (97 °C), flash point is 74 °F (23° C), and ignition temperature is 775 °F (412° C). It is toxic by skin absorption with a TLV of 200 ppm in air. The four-digit UN Identification number is 1274. The NFPA 704 designation is health 1, flammability 3, and reactivity 0. The primary uses are in brake fluid, as a solvent, and as an antiseptic. The structure and molecular formula for propyl alcohol are shown in Figure 5.53.