Keeping Dev in the Dark - Truth or Myth?

[Martin Aislabie]

Is this just urban legend or is there scientific proof (or good chemical theory) that Developers (Film & Paper) need to be kept in the dark.

I am not proposing that I store my Developers in the Porch to get the full blast of the sun but does it need total darkness?

Thanks

Martin

 

[Ian Grant]

Conventional wisdom was to store in brown glass bottle, away from direct sunlight. However I store mine (Pyrocat HD) in an old 1 litre Ilford white dev bottle in a room lit by daylight, again usually not in direct sunlight and it lasts the same as if kept in a cupboard.

Ian

 

[Sim2]

Is this just urban legend or is there scientific proof (or good chemical theory) that Developers (Film & Paper) need to be kept in the dark.
Martin

Well, personally I don't tell the dev anything at all, doesn't seem to have affected its confidence one bit!

Sorry, couldn't resist.

Seriously, never thought about keeping dev in the light - usually sits in a cupboard.

Sim2.

 

[ic-racer]

PE probably knows more about this, but Metol decays when exposed to UV. Though the metol is destroyed much, much, faster by oxygen free radicals.

The graph shows Metol without UV or free radical exposure on the top. The next curve is Metol exposed to UV and the lowest curve shows Metol exposed to UV and Free radicals.

Water Research
Volume 34, Issue 2, February 2000, Pages 463-472

 

[BetterSense]

I can't think of any reason at all why developer should be sensitive to light. It sounds like an urban legend to me.

 

[Ian Grant]

And as Glass filters out UV light how well would a clear glass bottle do compared to a brown bottle

It's not an urban myth though, usually if left in sunlight, so exposure to UV light, there's also heat from the sunlight.

Ian

 

[Mainecoonmaniac]

Light will degrade other items also

Light and air will degrade a lot of items. Ask any beer lover, wine lover and folks that deal with food ingredients. Pharmaceuticals also will degrade in light, air and heat.

 

[brianmquinn]

I hand mix most of my developers. I store them in clear glass bottles. That way I can see if they are discolored and going bad if they are an MQ developers. I then store them on an open shelf in a basement darkroom. I have had MQ print devlopers stored this way for several years in full clear glass bottles that worked just fine. But as a chemist I can tell you that I would never store them where they would be expised to direct sunlight (even through a window). UV light will degrade MOST chemicals. Just think of anything you have ever left out it the sun for a summer. It is faded and oxidized by the fall.

 

[Nicholas Lindan]

Developers are organic reducing agents (in common gobbledygook parlance 'anti-oxidants') and are subject to UV induced oxidation, well oxidation isn't exactly the right word but the UV strips away the compounds' reducing capability. All developing agents are similarly sensitive to UV: hydroquinone, metol, vitamin C, phenidone, pyrogalol, cathechol, etc., etc.. 'Oxidizer' doesn't necessarily mean oxygen the element, but a chemical that has the ability to borrow electrons from another chemical that would like to temporarily offload some - the two get combine in a redox reaction. However, the oxygen in air is the usual culprit that causes developer to go bad before use. If you keep developer in plastic bottles you will notice that the bottles get pinched in a few days - this is because the oxygen in the trapped air has been taken up by combining with the sulfite and developing agents.

Liquid developer is packaged in brown bottles to enhance shelf life at the store. When you get it home it sits in the darkroom, which is, well, dark. Brown bottles are a waste of money unless you keep your developer on a sunny window ledge.

'Free radical' is gobbledygook for an oxidizing agent - the concept of a 'bound radical' is an oxymoron, making the concept of a 'free radical' equally idiotic (sorry, it's a soapbox of mine).

 

[Pinholemaster]

"I can't think of any reason at all why developer should be sensitive to light. It sounds like an urban legend to me."

The break down of the developer is called oxidation. Sunlight accelerates the process. Basic chemistry, unless chemistry is an urban myth? HA!

 

[hrst]

For what it's worth, it's a myth in practice.

However, there's a truth behind it. If you stored your developers in very heavy sunlight all the time, there might be a problem. But you usually store them indoors at darkroom...

Clear bottles are better because you can judge solution for color and precipitate/gunk.

This has been discussed many times here.

 

[cowanw]

Ilfosol is sold in white plastic containers and sits on my camera store's shelf for ages.

 

[keithwms]

I generally keep all photo-related chems in fairly dark conditions - in cabinets and such. While this is certainly unnecessary for many chems, why spend the time to sort which ones will and which ones won't oxidize more rapidly.

Of course, if you are an experimentalist, then you can try keeping your chems in the sunlight and, who knows, with just the right mix, you might discover something interesting, just like Scheele did.

 

[MartinCrabtree]

Not to mention heating/cooling cycles cause other issues as well.

 

[wclark5179]

I'm in the dark on this one. Had to say it!

I keep my photo chemicals in a cabinet that is dark. I believe that light and ambient temp. has an effect on the life of photo chemicals.

Maybe that's why they have a long life here as cool Minnesota dark cabinet for storage = long life.

I do use mt 2 liter soda containers and I think that the good seal the cap provides also helps as well as the type of plastic the bottles are made makes for long life of photo chemicals.

Have our grand children here since July 4th and have 14 rolls of 120 B&W (FP4 & D-400) to develop! Plan to make more pics today as they leave this evening to go home. Smiles & Fun!

 

[Nicholas Lindan]

Ilfosol is sold in white plastic containers

Plastics absorb UV - to keep the plastic from being degraded most plastics also contain UV blockers. Chances are the bottle lets through very little UV.

 

[Martin Aislabie]

So, what I have picked up so far is:-

• UV in direct sunlight is bad for chemical storage.
  
• However, as Glass (windows) absorb a fair amount of UV, indoor ambient light (not direct sunlight) is OK~ish
  
• White HDPE Plastic bottles (the same as those developer comes in) are about as good as Glass for Developer Storage

Is this a reasonable summary?

Is there any more to add ?

Martin

 

[fotch]

My understanding is after you mix the developer, HDPE Plastic bottles is not the best for storage. Pet 1 (I think its called) that water and soda comes in is suppose to be good. I use amber glass with gas.

 

[Monophoto]

There are 8760 hours in a year.

The lights are ON in my darkroom for a total of about 10 hours a year. So regardless of the color of the container that developers are stored in, they are effectively stored in the dark.

Much ado about nothing?