Shelf life of Metol powder

[snusmumriken]

I use a metol-only developer formula (Barry Thornton’s 2-bath) which has a very long life as working solutions. 6 months can pass before I need to make fresh solutions. It takes aeons before I get through even the minimum purchaseable quantity of metol.

I have not so far had any problem with consistency, but it occurs to me that my supply of metol is now several years old. Reading this thread about phenidone made me wonder what the expected shelf-life of metol powder is, and whether there is any recognised way to extend it?

 

[koraks]

Ah, many years. These chemicals are pretty darn stable unless you allow moisture to get to the dry stuff.

Metol will turn brown and ultimately black. Anything white to tan has been reported to work OK. Mine happens to be more on the tan side of the spectrum.

 

[snusmumriken]

Ah, many years. These chemicals are pretty darn stable unless you allow moisture to get to the dry stuff.

Metol will turn brown and ultimately black. Anything white to tan has been reported to work OK. Mine happens to be more on the tan side of the spectrum.

Thank you! Question answered. That’s a relief. My metol is still a light tan colour.

Reckon this will be the shortest thread on the forum!

 

[koraks]

Reckon this will be the shortest thread on the forum!

You know better, don't you?

 

[Kino]

I have well sealed mason jars of Metol (and other raw chemicals) that are 20+ years old and are light tan and work fine. I was offered pounds of the stuff for free when a photolab was closing it's doors, so I invested in some pvc lids with heavy seals and keep it stored in a box under black paper.

Keep it sealed, dry and in the dark. When in doubt, test it.

Not much more you can do!

 

[John Wiegerink]

You know better, don't you?

Just to keep this going, I have some that is 30+ years old, and it still seems to work just fine. About three years or so back I was starting to wonder about my old metol, so I bought a small amount of new metol. I did test the old vs the new and can say for fact that I didn't need to buy the new metol. Better safe than sorry!

 

[RalphLambrecht]

Ah, many years. These chemicals are pretty darn stable unless you allow moisture to get to the dry stuff.

Metol will turn brown and ultimately black. Anything white to tan has been reported to work OK. Mine happens to be more on the tan side of the spectrum.

+1

 

[Nicholas Lindan]

Mine is ~20 years old and in its original plastic jar from Photographers' Formulary. It has a few black specs in it from a time I put the lid from the S. Carbonate jar on the metol container. Not tan yet, works fine.

Unless it has turned to the brown side of tan I wouldn't have any compunction about using it.

And then there is Cafenol - where the darker the brown the better.

 

[pentaxuser]

Thank you! Question answered. That’s a relief. My metol is still a light tan colour.

Reckon this will be the shortest thread on the forum!

The thread hasn't finished yet .

pentaxuser

 

[Donald Qualls]

I've mixed D-23 both last year and just a few weeks ago from metol that I've had on hand since 2005. Haven't used the new mix, but last year it worked fine. I agree, any metol that's no darker than turbinado sugar is fine, and even as dark as light brown sugar is probably okay. If 1% of the stuff is oxidized, it'll be pretty brown -- and that's too little loss to have any effect on your developer.

 

[relistan]

Reading this thread about phenidone made me wonder what the expected shelf-life of metol powder is, and whether there is any recognised way to extend it?

I wouldn't worry about phenidone, either. My supply is at least a decade old and works great. Keep it as a powder until its nearer time to using it.

 

[Kino]

The thread hasn't finished yet .

pentaxuser