Metol storage, should I...

paul_c5x4 · Jul 2, 2014

Got hold of some metol and have decanted it in to smaller containers - Small tubs, 25g batches, then vacuum sealed inside plastic bags (double bagged).

I'm not going to be using this stuff at a great rate (the last 25g batch I had took over a year to use up), so I'm thinking of storing the bulk of it in the freezer - Is this a sensible idea ?

AgX · Jul 2, 2014

The driest and coldest place you got. Seems right if perhaps not too much than necessary.

AgX · Jul 2, 2014

The driest and coldest place you got. Seems right if perhaps not too much than necessary.

If this is your general freezer than of course all safety measure against contact between foodstuff and chemicals apply.

AgX · Jul 2, 2014

The driest and coldest place you got. Seems right if perhaps not too much than necessary.

If this is your general freezer than of course all safety measure against contact and mixing up between foodstuff and chemicals apply.

Ian Grant · Jul 2, 2014

Metol keeps well, I have a few Kilos and although some is possibly 50 years old it's as good as when made. Store in a dry, dark place.

Ian

Gerald C Koch · Jul 2, 2014

Ian Grant said:
Metol keeps well, I have a few Kilos and although some is possibly 50 years old it's as good as when made. Store in a dry, dark place.

Ian

Same here, I too have some that is over 50 yeas old. It keeps very well. Keep it in a dark place as exposure to light will cause the normally white crystals to take on a purplish or grayish tinge with a small change in solubility. Keeping it in bags is not a good idea. A brown glass jar is a better choice. No need to keep it in the freezer.

AgX · Jul 2, 2014

What would be the disadvantage of a sturdy, well welded bag, aside of the better handling with a glass bottle?
Yes, the bottle will not be punched , have no static, keeps its form.

AgX · Jul 2, 2014

What would be the disadvantage of a sturdy, well welded bag, aside of the better handling with a glass bottle?
Yes, the bottle will not be punched , have no static, keeps its form.

But the question is about long term storage, not the stock for weekly use.

Gerald C Koch · Jul 2, 2014

A chemical's MSDS usually contains some general storage information such as "store in a cool, dry place protected from light" or "protect from excess heat." I encourage people to always read this information thoroughly when dealing with a new chemical.

Gerald C Koch · Jul 2, 2014

Plastic bags are permeable to oxygen and moisture which is never good for the storage of developing agents. They also can leak or break. The general rule with chemicals is to leave them in their original containers unless there is some important reason to transfer them. This would include a damaged container or a plastic one for air sensitive chemicals. Unfortunately companies are more concerned with shipping weight than with proper storage. Metol is a possible skin and eye irritant and this should always be considered in its storage. The less you handle this chemical the better.

AgX · Jul 2, 2014

Yes, I got itching blisters from seconds of contact wich Metol-containing developer concentrate.

Xmas · Jul 2, 2014

paul_c5x4 said:
Got hold of some metol and have decanted it in to smaller containers - Small tubs, 25g batches, then vacuum sealed inside plastic bags (double bagged).

I'm not going to be using this stuff at a great rate (the last 25g batch I had took over a year to use up), so I'm thinking of storing the bulk of it in the freezer - Is this a sensible idea ?

Some photo chemicals are dangerous.
It's not like making wine or beer.

lm shooting beside a stranger in street market and notice he has a pro DSLR and lens.
'Is that VR?'
'Yes I need it for the Parkinson's'
'In family?'
'The 2nd question the consultant asked was have you handled photo chemicals.'

@Paul

No it is toxic and needs to be in original container.
As dry power it is stable long term - decades
If you don't understand the hazchem label use a lab.

@AgX

Suggest you need to avoid all Metol in future. PQ in place of MQ. MICROPHEN in place of d76.
And you need to use barrier cream and inspection gloves with any cyclic chemicals in future. Face mask and goggles with powders.
The reaction may be no different from a food allergy or wasp sting.
It may only be the high pH and skin cracks but Id not risk myself.

dynachrome · Jul 2, 2014

Many years ago I discarded the better part pf a pound of Kodak Elon. I had been using it to make mostly D-23. I wish I still had it.

Gerald C Koch · Jul 3, 2014

AgX said:
Yes, I got itching blisters from seconds of contact wich Metol-containing developer concentrate.

My problem is with p-phenylenediamine and the color developing agents based on it. The last time I did any color printing I got blisters the size of peas n my hands that itched intensely for days. I had to abandon color printing.

Xmas · Jul 3, 2014

Gerald C Koch said:
My problem is with p-phenylenediamine and the color developing agents based on it. The last time I did any color printing I got blisters the size of peas n my hands that itched intensely for days. I had to abandon color printing.

Hi Gerald

Please also see advice for AgX above.

Noel

paul_c5x4 · Jul 3, 2014

Xmas said:
No it is toxic and needs to be in original container.
As dry power it is stable long term - decades

The "original container" was a ziplock bag - Far from ideal. It is now decanted in to small pots of 25g each and vacuum sealed inside some sturdy bags. Stored alongside the film & paper in a freezer set aside specifically for the purpose, so contamination of food is minimal. That said, I have other things that will kill long before exposure to a bit of metol.

Gerald C Koch · Jul 3, 2014

paul_c5x4 said:
The "original container" was a ziplock bag - Far from ideal. It is now decanted in to small pots of 25g each and vacuum sealed inside some sturdy bags. Stored alongside the film & paper in a freezer set aside specifically for the purpose, so contamination of food is minimal. That said, I have other things that will kill long before exposure to a bit of metol.

I think the point of some of the posts was to transfer that bag's contents to a brown glass jar and not worry further. Transferring it to a number of small bags is unnecessary. The Metol will be fine at room temperature. I personally would nor store developing agents alongside paper and film.

Rudeofus · Jul 3, 2014

Gerald C Koch said:
My problem is with p-phenylenediamine and the color developing agents based on it.

This should not come as surprise, and from what I read the actual compound causing allergic reactions to Metol is some PPD impurity. I am, though, a bit surprised that modern color developers cause you so much trouble, IIRC they were designed/chosen specifically for being less of an allergen. I guess you became sensitized by exposure to straight PPD and now your immune system responds violently to anything that looks similar.

All this shouldn't prevent you from color printing, though. I process my RA4 prints in drums on a Jobo CPE-2 with lift arm, and never have any direct contact with the processing liquids. I personally would not want to work with trays in complete darkness.

AgX · Jul 3, 2014

Rudeofus said:
I personally would not want to work with trays in complete darkness.

Well, there still are those vertical/oblique slit tanks by Nova or Jobo. And there is sodium-vapour lighting.

Xmas · Jul 3, 2014

paul_c5x4 said:
The "original container" was a ziplock bag - Far from ideal. It is now decanted in to small pots of 25g each and vacuum sealed inside some sturdy bags. Stored alongside the film & paper in a freezer set aside specifically for the purpose, so contamination of food is minimal. That said, I have other things that will kill long before exposure to a bit of metol.

My Metol came in a solid sealed container with hazchem barcode etc.
Ziploc seems incautious.
Id have repacked too.

Xmas · Jul 3, 2014

Rudeofus said:
This should not come as surprise, and from what I read the actual compound causing allergic reactions to Metol is some PPD impurity. I am, though, a bit surprised that modern color developers cause you so much trouble, IIRC they were designed/chosen specifically for being less of an allergen. I guess you became sensitized by exposure to straight PPD and now your immune system responds violently to anything that looks similar.

All this shouldn't prevent you from color printing, though. I process my RA4 prints in drums on a Jobo CPE-2 with lift arm, and never have any direct contact with the processing liquids. I personally would not want to work with trays in complete darkness.

Yes there is a serious risk of sensitization with many of the cyclic chemicals.
But I thought the colour developers were as exposed as metol?
If you are sensitized you may not be able to tolerate traces of metol or similar agents.

http://www.ncbi.nlm.nih.gov/m/pubmed/6734190/

David Lyga · Jul 3, 2014

Bought some metol in 1974. STILL GOOD. Stored in a plastic bottle, certainly not full. No problem. Keep away from excess humidity. Hydroquinone a bit trickier (more hydroscopic) but still, again, no problem storing that way, for that long. - David Lyga

Rudeofus · Jul 4, 2014

Xmas said:
Yes there is a serious risk of sensitization with many of the cyclic chemicals.

Just because a compound is cyclic doesn't mean it is toxic or and allergen. Just look at Ascorbic Acid or beta-Carotene, which you (hopefully) eat every day ...

Xmas said:
But I thought the colour developers were as exposed as metol?

The primary culprit is PPD, which is also a (very poor) color developer (still contained in today's hair dyes AFAIK). It is contained as trace impurity in Metol, and it is the main reason why people are sensitive/allergic to Metol. Today's color developers are said to be a lot less problematic than PPD and shouldn't cause these hypersensitivities. I can imagine, though, that someone once sensitized by PPD in Metol or in ancient fine grain developers may now be sensitive to anything resembling PPD, and all of today's color developers (CD-3, CD-4) are similar to PPD.

Ian Grant · Jul 5, 2014

Sensitivity to Metol has been known for decades and to a large extent depends on its purity (as Rudeolfus states), I've numerous adverts extolling the purity of various manufacturers which have no skin sensitivity.

I don't use it much because I prefer Phenidone as it's better (as in gives warmer tones) in Warm tone developers and I now only use Pyrocat HD as a film developer (all formats 35mm upwards).

SO I'll be selling off my at least 75% of my Kilos of Metol soon

Ian

Gerald C Koch · Jul 5, 2014

Some years ago the method of synthesis for Metol was changed and no longer used p-phenylenediamine as a starting point. The resulting product of the new synthesis produces less problems.

Metol storage, should I...

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