Metol and hydroquinone dry shelf life?

[Jarin Blaschke]

Hi everybody:

I'm printing tomorrow after a long absence, and will making a batch of Ansco 130 in the morning beforehand. I ordered fresh glycin but planned on using my existing Metol and Hydroquinone in the cabinet. However, now I'm suddenly questioning myself and wonder if I need to be safe and run to Freestyle before I go to the darkroom.

My metol I procured in September 2014. It's an off-white to tan color and I don't see any darker specks.
My hydroquinone I procured in July 2013 and it looks the same - long white crystals.

Any input on the shelf life of these chemicals?

Jarin

 

[RalphLambrecht]

Hi everybody:

I'm printing tomorrow after a long absence, and will making a batch of Ansco 130 in the morning beforehand. I ordered fresh glycin but planned on using my existing Metol and Hydroquinone in the cabinet. However, now I'm suddenly questioning myself and wonder if I need to be safe and run to Freestyle before I go to the darkroom.

My metol I procured in September 2014. It's an off-white to tan color and I don't see any darker specks.
My hydroquinone I procured in July 2013 and it looks the same - long white crystals.

Any input on the shelf life of these chemicals?

Jarin

I may be too optimistic but I never replace bulk chemicals with fresh until the existing stock is gone.

 

[Ian Grant]

50+ years with no issues.

Ian

 

[Gerald C Koch]

50+ years with no issues.

Ian

+1

I might add that they should be stored in glass containers (preferably brown glass) in a cool dark place.

 

[mrred]

Yeah, the last time I bought Metol it was a 5 lb jug. There is no way I can burn through this quick. The stuff is ok as long as it's sealed.

Glycin...freeze it and tape around the cap. I have a bottle that I just used the last of it and it was over 5 years old.

 

[Jarin Blaschke]

Ian:

50 year-old Metal and hydroquinone, working fine?

J

 

[Ian Grant]

They work as if new, as does Ilford Phenidone from 1963.

Ian

 

[Gerald C Koch]

If these two chemicals are exposed to light they will turn a light purplish-gray in color. Their activity is not affected.

The following developing agents have a limited life.

o Glycin, solid oxidizes rapidly when exposed to air.
o p-aminophenol, either as the free base or the HCl salt
o p-phenylenediamine, either as the free base or the HCl salt
o Amidol
o pyrogallol
o ascorbic acid, solid oxidizes when exposed to air. Keep well sealed and away from light.

 

[destroya]

If these two chemicals are exposed to light they will turn a light purplish-gray in color. Their activity is not affected.

The following developing agents have a limited life.

o Glycin, solid oxidizes rapidly when exposed to air.
o p-aminophenol, either as the free base or the HCl salt
o p-phenylenediamine, either as the free base or the HCl salt
o Amidol
o pyrogallol
o ascorbic acid, solid oxidizes when exposed to air. Keep well sealed and away from light.

so what would you say the shelf life of properly stored pyrogallol is?

 

[Gerald C Koch]

so what would you say the shelf life of properly stored pyrogallol is?

Unlike some of the other developing agents I personally have no information to give a figure. I consider it too toxic to keep around the house. But in a well sealed glass bottle I would say a few years. But certainly not 50. This takes into account the increased activity over hydroquinone and catechol. The solid also easily turns brown on exposure to air. Keep it well sealed, away from heat, light and moisture.

There are two forms of pyrogallol sold. One form consist of small chucks and the other a feathery powder. Avoid the powder form as it becomes airborne too easily making it more dangerous.

 

[ritternathan]

Any idea as to how long p-aminophenol base will last in a mason jar in a cool, dry, dark place? I've got about 300g of it and don't know when I will use it again. Thanks, Nathan

 

[DREW WILEY]

I have no idea. I buy this stuff in bulk and am still using some powder probably twenty years old for MQ formulas, and it's fine. I keep it dry.
Glycin is a different subject. It oxidizes and changes. So I keep the reserve bottles of that sealed and frozen.