[Janeymiddlewife]

I have opened an old tin of this which I used last year when it was rather solidified. It has been kept in the garage until recently, but on opening it has partly liquified. Will it still be effective? Can you still buy it or has it too been outlawed??

[arugula]

It seems to be available quite widely still (info from Google). Regards the efficacy, as it is water soluble, will it not be fine still? 

[Janeymiddlewife]

It seems to be available quite widely still (info from Google). Regards the efficacy, as it is water soluble, will it not be fine still? 

I'll let you know - serves me right for using old compost, most of my dahlia seedlings have succumbed 

[JayG]

Should be OK; active ingredients are the inorganic salts copper sulphate and ammonium carbonate so it is the same type of copper-based fungicide as Bordeaux mixture (although only registered for use for controlling damping off disease in seedlings)

[Goosegirl]

I am guessing that the crystals are deliquescent - i.e. take in water from the atmosphere - that's why it had solidified in the first year then has taken in more water over winter to become partially liquid. Should be ok to use though.