Paraffin is a petroleum distillate. If you buy it at the supermarket (get the type used to seal jelly jars), it is relatively free of additives, since it's meant to be in contact with food.
If you're British, don't use paraffin to lubricate your zipper, as to a Britishperson, paraffin is a liquid fuel used in jet aircraft.
For non-British bicyclists (especially in dry areas), paraffin wax is one of the preferred chain lubricants, as it doesn't pick up dirt/dust/etc.
Beeswax tends to be softer than paraffin wax.
Carnauba wax (most often used as furniture or car wax) is harder than either beeswax or paraffin, and can also be used as a lubricant. (I apply a thin coat of Carnauba wax on the ways of a wood lathe, for example). At room temperature, beeswax is a better lubricant than paraffin wax, which is a better lubricant than Carnauba (better is defined as lower friction).
Carnauba is of vegetable origin; beeswax of animal origin, and I suppose you could say paraffin is of dead dinosaur origin
(mineral, if you must).
All petroleum distillates will damage latex rubber to some degree. Synthetic rubbers (e.g. neoprene) are more resistant to petroleum products. All waxes (and oils, whether animal, vegetable, or mineral) shed water. Some animal and vegetable-based waxes (and oil) are actually fatty acid esters, and can cross-link or go rancid on you with age. Most (if not all) mineral-based oils & waxes will keep forever.
That said, if you buy a pound of paraffin at the supermarket, and you only use it to lubricate zippers, it will last you until you misplace the wax!
