A versatile liquid listed as safe for human consumption by the Food and Drug Administration, glycerine is viscous, colorless, and has a slightly sweet taste. Food and drug makers use it in everything from candies to toothpaste. It can both dissolve and be dissolved by many substances. Glycerine lowers the freezing point of water, and it can be used as a lubricant for applications where oil isn’t suitable.
Glycerine is completely colorless, having a clear appearance similar to water and alcohol. Its index of refraction is 1.49, which is somewhat higher than water. This value is close to that of crown glass or an 80% sugar solution. Gycerine’s lack of color makes it useful as an additive with other substances. It gives products a glossy appearance but adds no coloration of its own.
According to the Hyperphysics web site, glycerine is almost over 1500 times more viscous than water. This means, when glycerine is a liquid at normal temperatures and pressures, it flows and pours very slowly. This property makes it useful for making a variety of food products that need extra body, such as candy and icings, as well as products like toothpaste.
According to Sevas Bioinformatics, glycerine dissolves completely in both water and alcohol. While many solvents dissolve either polar or non-polar substances, glycerine does both. It can also dissolve many organic and inorganic substances. Its versatility as a solvent and its relative safety makes it useful for producing pharmaceuticals.
More resistant to oxidation than mineral oils, glycerine is used as a lubricant. It can be used where mechanical parts are exposed to benzene or gasoline, as these substances won’t dissolve glycerine as they would dissolve oil. You can mix graphite powder into glycerine to further improve its lubricating properties. If its viscosity is an issue, glycerine can be mixed with water or alcohol to thin it, making it flow more quickly around lubricated parts.