That probably is lime dust. This looks a lot like the funace area of the mill where I work. It is amazing how fast lime dust can build up.

I deal with diferent types of seizures every day> I am the father of an epileptic (LGS) who has anywhere between 3 and 20 seizures a day. She has myclonic, tonic clonic, atonic, partial complex, ocular, and focal seizures.