[gotocake]

I think it's still reasonable to fear some ambient level of this stuff could do us harm over time despite being marketed as 'harmless'. See: asbestos.

Or heroin, cocaine, morphine, OxyContin, radioactive drinking water, bleeding the sick, DDT, Lead drinking vessels and pipes, doctors not washing their hands between an autopsy and a birth, taking antimony pills as a purgative, and... you get the idea.