E-6 first developer does deteriotate. I have a gallon of the stuff expired 07 gifted to me 08. I now, though trial and error, mix it at 110%of spec concentrate, to process with good results at spec time and temp.

The RB concentrate seems to last. When it poops out on me, I resort to optical reexposure, or use a tiny some of my store of the exotic sodium borohydride to chemically reverse.

Colour Developer- the part with the developing agent I store in small glass bottles in the coor dark of my basement darkroom. They seem to last a few years past expiry if packed if the developing agent is put in glass when still fresh.

Bleach lasts.

Fix concentrate can sulfate out. Other fixes will work, if pH is trimmed to the e-6 spec.