Glycerol
Chemically
Glycerol - a clear, viscous, odourless, slightly sweet, non-toxic, liquid
- used e.g. as a humectant, a solvent, a sweetener, a preservative, a thickening agent
- has some anti-freeze properties
- has a few medical uses
- A specific compound (C3H8O3), and technically a triol (with three OH groups)
Glycerol and glycerin (US) / glycerine (UK) refer to the same molecule, but glycerin is a commercial term that typically refers to mixes that are mostly (>95%) glycerol.
See also:
More widely, you can look at diols and triols.
You may see the term glycol[1], which is the property/grouping of aliphatic diols, where
- aliphatic = non-aromatic
- diol = alcohols with two OH functional groups (triols have three)
Some compounds in this area include (but are certainly not limited to)
- glycerol (E422), as mentioned
- propylene glycol, somewhat similar to glycerol
- E1520 when used for food
- E490 when used for cosmetics
- ethylene glycol (used in classical antifreeze, and toxic)
Uses
Smoke machine fluids were often basically just glycerol (sometimes other glycols, but not ethylene glycol) and water, though there appear to be some newer formulations that leave less residue(verify).
Vaping liquid has a base that is often a mix of part glycerin (smoother, cloudier) and propylene glycol.
Used as a sweetener, humectant, preservant, and is used in personal lube.