In my Younger daze as a "Forced Labor" employee at my dads Tire store, (after all...that's why we had kids, right?) I can state without doubt that all new tires off the rack have rubber dust on them. I often came home covered in the stuff and my mom would complain about having to clean it out of the showers almost daily. It is by-product of the manufacturing process, and when it gets washed off after a while, people want to get that new tire look back by slapping armour-all on it. Which destroys the surface over time.
2002 Ford F-250 7.3 PSD CrewCab. 18K Pullrite Super glide, DP F6 Tuner, Ride Rite Air Bags, Torklift Stableloads, 2011 Crusier CF31REP Patriot