On 6/21/23 01:50, Christian Corti via cctalk wrote: > On Tue, 20 Jun 2023, Chuck Guzis wrote: >> the cookie to a clean jacket after cleaning. If it's oxide shedding, I >> use a couple of drops of cyclomethicone on each side. > > Is it essentially the same as silicone oil? Because cyclomethicone is > just a category for three different cyclic siloxanes (D4, D5 and D6), > namely cyclotetrasiloxane, cyclopentasiloxane and cyclohexasiloxane. > D4 and D5 have been put on the ECHA list of forbidden substances in 2018. > So, what exactly do you use? ;-)
This stuff: https://pubchem.ncbi.nlm.nih.gov/compound/Decamethylcyclopentasiloxane The ECHA documents are linked. As far as I can determine, use has been restricted, not forbidden in the ECHA. The cosmetics industry would likely go bankrupt without it. I'm not suggesting that anyone drink it or bathe in it (although it is used in many shampoos), but then, neither am I suggesting people bathe in petrol either, although it's useful and carcinogenic. Manufacturing data shows that at least a hundred million tons of the stuff is manufactured yearly. I use it on disks and tapes because it's a lubricant that's both chemically inert and volatile; that is, after using, it evaporates and leaves the medium unaffected. Make your own decisions. --Chuck
