This article is from the Bicycles FAQ, by Mike Iglesias with numerous contributions by others.
From: email@example.com (Rich Gibbs)
Date: Wed, 09 Sep 1998 04:03:00 GMT
There have been many opinions posted here on WD-40's composition, but
here is what the Material Safety Data Sheet [MSDS] says (it's from Oct
93, the latest I could find):
50% Stoddard solvent (mineral spirits) [8052-41-3]
25% Liquified petroleum gas (presumably as a propellant)
15+% Mineral Oil (light lubricating oil) [64742-65-0]
10-% Inert ingredients
(The numbers in square brackets '' are the CAS numbers for the
ingredients, as listed in the MSDS.)
Mostly, WD-40 is a solvent, with a bit of light oil mixed in. It
doesn't contain wax (except incidentally, since it's not exactly a
Personally, I use it sometimes for small cleaning jobs, but it's not a
particularly good lubricant for anything that I can think of, offhand.