Hi, I'm a 1st-time poster in the chemistry forum. (Only did 1 year of chem at Uni.) I'm trying to understand the content of an organic paint-additive product "Penetrol". http://www.floodaustralia.net/products/paint_additives/penetrol.php The MSDS can be downloaded from this page: http://www.floodaustralia.net/safety/ On the 2nd page of the MSDS, it says the product has 57% "Stoddard solvent", CAS No 64742-47-8 <11% "Mineral spirit", CAS No 8052-41-3 Looking on Wikipedia, i.e., here: http://en.wikipedia.org/wiki/Mineral_spirit , I get impression that "Stoddard solvent", "Mineral spirit", "Mineral Turpentine", and "White spirit" are all the same. But if so, why do they have different CAS numbers? And why list them separately in the MSDS? Can any organic/industrial chemists here shed some light on this?