There are five temperature scales one might encounter, but only the first three listed here are of any current significance. Here is a handy calculator to convert between any of these. Specific definitions of each scale are given in the next section. Tip: If you convert a negative temperature, be sure to include the negative sign! For example, -31 oF= -35 oC, but +31 oF = -0.56 oC! Additional Info: Many of the items you will find on an MSDS come in both English (U.S. Customary System) and metric (International System or SI or cgs) units. The metric system has been adopted by almost every country except the United States. Even in the U.S., scientists and technical people use the metric system because of its ease of use. MSDS Relevance: Be very careful to note the units when reading temperatures on an MSDS. These are usually, but not always, in degrees Celsius. Also remember the tip above; when converting between units, be sure to include the negative sign in your calculation instead of (mistakenly) sticking it in at the end. As with any calculation you write out by hand, be sure to write out your units and make sure they cancel to the desired unit. See also: Area Units, Distance Units, Mass Units, Mole, Pressure Units, Temperature Units, Volume Units