I did the sensible thing... just sent an email off to an Adorama rep for clarification. According to the manufacturer's SKU listed, and cross referencing it to PF site, it appears to be just a regular hydroquinone.

Apparently, people use residual hydroquinone, whatever it is, to make skin whitening cream. I wonder if they have to bathe in fixer to make that permanent? Looking at MSDS, this stuff isn't entirely harmless at higher concentrations....