A guess only, the Hydroquinone. Badly oxidized Dektol,
which is a powder, looks like coffee grounds and has a
strong smell which is hard to describe, a sort of
combination of burning electrical insulation and rotting
fish.
  Polymax is a liquid concentrate version of Dektol. Its
not identical in formula but the working solution is the
same in its action. I would dump it.
  Currently, I am using Agfa Neutol Plus. This is a liquid
concentrate using Ascorbic acid and, I am pretty sure,
Phenidone. The concentrate is light orange. It is as active
at the "economy" dilution of 1:9 as Dektol is at 1:2, maybe
more, and seems to have a large capacity. Also, it does not
leave silver deposits on the tray.