Provided by the Center for Disease Control's (CDC), National Institute for Occupational Safety and Health (NIOSH), this historic image, shot inside a Connecticut hat manufacturing plant, depicted a fur mixing machine. Note PHIL #9677, which showed the chain of events through which the animal fur passes on its way to becoming a hat, and you'll see that the second step after the fur had already been 'carroted' includes, 'Layering, Mixing, and Blowing'. Being that the manufacturing process involves the use of mercury nitrite, if precautions were not taken, such as wearing a filtered breathing mask, or gloves, mercury exposure was quite likely, and could have lead to heavy metal poisoning, with severe pathologic neurological consequences.
CDC/ Barbara Jenkins, NIOSH
November 27, 2012