Temperature for storing chemicals

Hello,

Recently I've bought chemistry for film photography (B&W LC29 dev., Ilford Rapid fixer, Fomacitro and Fotonal wetting agent). Also I bought distilled water. I didn't open it yet and I am not sure what is the best storing temperature for them in my situation. My room temperature is from 21.6ºC / ~71ºF to 23ºC / ~73ºF which is a bit too high for storing chemistry. Also I do have some space in my apartment building cellar to store chemistry but the cellar room is not heated and the temperature is not constant. I've checked the temperature two times and here are the results:

On 2023 Nov. 28th at 00:43h the temperature inside cellar room was 14.1ºC / ~57ºF. Outside temperature at that time was -6ºC / 21ºF
On 2023 Dec. 02nd at 16:09h the temperature inside cellar room was 15.4ºC / ~60ºF. Outside temperature at that time was -1ºC / ~30ºF


Question: is it better to store chemistry at over 20ºC / 68ºF but under 23ºC / ~73ºF (average: 21.5ºC / ~71ºF) temperature or is it better to store it at over 14.1ºC / ~57ºF and under ~16ºC / ~61ºF to get the best condition and effectiveness out of chemistry?

Also what humidity temperature is the best for storing chemistry in your opinion?

Thank you!

lukajaku said:

My room temperature is from 21.6ºC / ~71ºF to 23ºC / ~73ºF which is a bit too high for storing chemistry.

Click to expand...

It's just fine.

Don't overthink it.

If you want to get into a deeper layer of complexity:
The fixer, stop bath and wetting agent basically don't care what temperature you store them at, but for the fixer it's a good idea to not go too low. Room temperature in a broad sense is absolutely fine, and it doesn't matter if this is 15C or 30C.

The developer will deteriorate faster at higher temperatures, but what really influences this process is how much contact there is with oxygen. If you want to mimimize this, you could for instance use something like Protectan spray to put a protective 'blanket' of heavier-than-air gas on top of it every time you open the bottle for use. Alternatively, you could decant the contents of the larger bottle into smaller, glass bottles and use those up one by one, keeping the other ones entirely full and tightly capped.

lukajaku said:

Also what humidity temperature is the best for storing chemistry in your opinion?

Click to expand...

These concentrates are pretty humid by themselves. In fact, they're mostly water.
They also come in water-tight containers so humidity of the environment doesn't matter at all. The only thing it'll influence is deterioration of the paper labels/stickers on the bottles.

Room temperature is a subjective issue. When I lived in Turkey most of the year our apartment was around 30ºC, rising to over 40ºC in July/August if we didn't use the air-conditioning. The apartment is ground floor, I stored my film in a bedroom drawer, just above floor level, my digital thermometer was in the same drawer and even on the hottest days never went to more than 21-23ºC. My developer & fixer were stored in the bathroom sink cupboard, most of the year they were at a fairly constant 27ºC, I assume using the hot water tap caused the slight rise,

Heat rises so there can be a steep temperature gradient between floor and ceiling. If you are concerned store on a low shelf.

Ian

The cellar room might be better for film, but both are fine for chemicals.

Ian Grant said:

...Heat rises so there can be a steep temperature gradient between floor and ceiling. If you are concerned store on a low shelf...

Click to expand...

Tangential picayune correction from a pain-in-the-neck engineer. Hot air rises (convects). Heat radiates from higher to lower temperature surfaces.

koraks said:

It's just fine.

Don't overthink it.

If you want to get into a deeper layer of complexity:
The fixer, stop bath and wetting agent basically don't care what temperature you store them at, but for the fixer it's a good idea to not go too low. Room temperature in a broad sense is absolutely fine, and it doesn't matter if this is 15C or 30C.

The developer will deteriorate faster at higher temperatures, but what really influences this process is how much contact there is with oxygen. If you want to mimimize this, you could for instance use something like Protectan spray to put a protective 'blanket' of heavier-than-air gas on top of it every time you open the bottle for use. Alternatively, you could decant the contents of the larger bottle into smaller, glass bottles and use those up one by one, keeping the other ones entirely full and tightly capped.



These concentrates are pretty humid by themselves. In fact, they're mostly water.
They also come in water-tight containers so humidity of the environment doesn't matter at all. The only thing it'll influence is deterioration of the paper labels/stickers on the bottles.

Click to expand...

Thank you for this information. It is very useful to me!

Can I ask for examples of Protectan sprays please?

MattKing said:

The cellar room might be better for film, but both are fine for chemicals.

Click to expand...

Thank you, Matt. Your tips are always useful!

lukajaku said:

Can I ask for examples of Protectan sprays please?

Click to expand...

Google it, it's a specific product name. But anything heavier than air will work. Butane is popular because it's easy to purchase as the gas to refill cigarette lighters.

Ian Grant said:

Room temperature is a subjective issue. When I lived in Turkey most of the year our apartment was around 30ºC, rising to over 40ºC in July/August if we didn't use the air-conditioning. The apartment is ground floor, I stored my film in a bedroom drawer, just above floor level, my digital thermometer was in the same drawer and even on the hottest days never went to more than 21-23ºC. My developer & fixer were stored in the bathroom sink cupboard, most of the year they were at a fairly constant 27ºC, I assume using the hot water tap caused the slight rise,

Heat rises so there can be a steep temperature gradient between floor and ceiling. If you are concerned store on a low shelf.

Ian

Click to expand...

From my experience as a visitor, room temperatures around 60F are considered normal for southern Florida.

The rate of such chemical reactions as might occur in the developer generally increases by a factor of 2-3 for each 10C temperature increase.