watch out for the thiosulfate sulfuring out. Pour it into a separate jug before adding it to the mix. If there is sulfur on the bottom of the bottle, then look to the formula to make your own. The red bottle part of theblix is amm Ferri EDTA, and should still be good. The first developer might be off - llok to see how dark it has gotten. Experiment with a non-critical roll first. I used these up to 3 years out of date and they were ok.