No WD40 does not have silicon in it. It is also Non-toxic, although I wouldn't go drinking the stuff and no, there is no Kerosene in it either.
I have a freind at NASA that know a freind and so on, that deveolped this stuff. They needed something to coat satillite parts
in. They tired many formulaes and many compounds and the name "WD-40" was simply "water dispersent test batch No.40". They found it had many other uses over time and NASA found they had made a true miricle product. Unfortunatly, it was never made to be a specific application for many of the things it does get used for, but it does OK. So many products that come along today that are job specific, tend to do the job better and thus WD-40 gets a bum wrap. The initial job it was designed to do was to displace moisture on sensitive electronic parts