Chemistry 101

ntenny · Sep 29, 2011

ChristopherCoy said:
So basically,

-dont drink your fixer
-dont take a bubble bath with your developer
-and don't go mixing things in manners the instructions don't tell you to.

Isn't all of that known as common sense?

You'd think so, but there's a certain DIY ethic that legitimately clashes with that third bullet point. I mean, the instructions don't tell you to mix coffee and washing soda to make developer, either, but it's pretty well established that nothing bad happens as long as you don't drink the result. So a more realistic guideline might be "don't go mixing things unless you know what to expect", but that's also easier for a reasonable person to mess up ("well, I *thought* I knew!").

By the way, the mnemonic I learned in chemistry class was "do what you oughter: add acid to water", which is goofy but memorable.

I like the idea of a sticky "elementary darkroom chemical safety" document.

-NT

Gerald C Koch · Sep 29, 2011

ChristopherCoy said:
So basically,

-dont drink your fixer
-dont take a bubble bath with your developer
-and don't go mixing things in manners the instructions don't tell you to.

Isn't all of that known as common sense?

Let me add that it is wise to use eye protection when diluting concentrates such as developer and stop bath. Most people have no idea of what to do if a chemical should get in the eyes.

Darkroom chemicals are not innocuous and many are dangerous if handled incorrectly. Always read the warnings on the label.

The main problem with common sense is that it is not at all common!

Vaughn · Sep 29, 2011

It is nice working for a university with a friendly Chemistry Dept. I have a pound of Potassium clorate that is one semi-solid chunk. When I needed a small amount, I gave a call over to the Chemistry folks to 1) make sure that its age would not be a factor and 2) if it was safe to knock off a chunk. I was told it would be fine, and not to use too big of a hammer.

Kodak Rapid Fixer Part B (hardener) will eat thru your clothes nicely -- lost a pair of jeans that way years ago.

Klainmeister · Sep 29, 2011

Wait wait wait.....I thought that hypo-clear was great for cleaning my contacts, and pyro is a great base for my Pyro Hot Sauce (copyright pending). I think you're all just being sissy-nannys.

michaelbsc · Sep 29, 2011

K-G said:
Correct , but the total amount of common sense seems to be shrinking at the same pace as the polar caps do.

Karl-Gustaf

Nah. I think common sense is receding far faster than the ice caps. Have you seen what's going on in Washington lately? How much common sense can be left?

Roger Cole · Sep 29, 2011

Some of this is just sensible, and some sounds more than a bit alarmist to me. Rapid Fix part B, the hardener, contains sulfuric acid. Sure it will eat through your clothes. So will battery acid. I've lost jeans to battery acid when working on the battery connections to a diesel generator where I used to work, but I've never lost clothes to fixer hardener, because it comes in a nice little bottle that's a lot easier to handle. I knew what the battery acid would do to clothes and wore old clothes I didn't care about and tried not to get any on them, but sometimes it happened. I'm not about to drink either one, or wash my hands in them.

Some of this honestly strikes me as, "if you're dumb enough to do that, let Darwin have his say."

K-G · Sep 29, 2011

michaelbsc said:
Nah. I think common sense is receding far faster than the ice caps. Have you seen what's going on in Washington lately? His much common sense can be left?

True ! I do hope the polar caps will hang in longer than common sense on Capitol Hill .

Karl-Gustaf

Vaughn · Sep 29, 2011

Roger, our Part B use to come in 5 gallon cubetainers (now in 76oz bottles)...and someone else spilled it along the edge of the sink's countertop, thus when I leaned across the counter, I thought is was just water.

I mentioned it because unlike battery acid, "Part B" does not sound very dangerous.

Photo Engineer · Sep 29, 2011

Vaughn said:
It is nice working for a university with a friendly Chemistry Dept. I have a pound of Potassium clorate that is one semi-solid chunk. When I needed a small amount, I gave a call over to the Chemistry folks to 1) make sure that its age would not be a factor and 2) if it was safe to knock off a chunk. I was told it would be fine, and not to use too big of a hammer.

Kodak Rapid Fixer Part B (hardener) will eat thru your clothes nicely -- lost a pair of jeans that way years ago.

You are a very lucky guy. If there were any organic contaminants in the Chlorate and you had hit it hard enough, you would not be around to tell the story. I split a Railroad Tie with Potassium Chlorate once by hitting a contaminated sample with a hammer.

PE

Gerald C Koch · Sep 29, 2011

Roger Cole said:
Some of this is just sensible, and some sounds more than a bit alarmist to me.

I don't think that saying people should be careful and always know what they are doing is in any way "alarmist."

Vaughn · Sep 29, 2011

Photo Engineer said:
You are a very lucky guy. PE

I am even a bit nervous just having in my office -- which is why I called the Chemistry Dept...and I did not hit it hard! It is stored away from any other of the chemicals I have in here.

Roger Cole · Sep 29, 2011

Vaughn said:
Roger, our Part B use to come in 5 gallon cubetainers (now in 76oz bottles)...and someone else spilled it along the edge of the sink's countertop, thus when I leaned across the counter, I thought is was just water.

I mentioned it because unlike battery acid, "Part B" does not sound very dangerous.

Sorry Vaughn, not picking on you. It is indeed easy to mistake a clear liquid like water along a sink where one would expect water for being water, whereas drops on a wet cell battery one pretty well assumes to be battery acid. That's a good point.

Roger Cole · Sep 29, 2011

Gerald C Koch said:
I don't think that saying people should be careful and always know what they are doing is in any way "alarmist."

Well of course not. But that's not how some of this comes across, at least to me. And I have no issue with your original post either. I'd have to go back through the thread to find examples that sound over the top to me. If they don't to someone else, fine.

And why, for the ten thousandth time, is APUG the only vBulletin site I use that doesn't allow multiquoting? Argh.

Gerald C Koch · Sep 29, 2011

This might prove useful for those experimenting. The American Chemical Society has assigned each chemical with a unique number, the CAS number. If you have any doubt as to whether two names apply to the same chemical look at the two CAS numbers. If they are not identical then the chemicals are not identical.

There is a classical chemistry demonstration as to the difference between silver cyanate and silver fulminate. Both substances have the same emperical formula. One is extremely explosive and the other is not. The different CAS numbers show that they are different.

Photo Engineer · Sep 29, 2011

I think that due to some recent posts and threads here on APUG, it became obvious that people are doing a lot of "experimenting" who have no knowledge of chemistry at all and Jerry has jumped in to help save them from possible grief.

I myself, have tried to prevent accidents when people were advised to heat chemicals in cook pots on the stove and etc..... Or, even heating chemicals in the microwave. All of these are dangerous practices that should not be done, especially for the average unprepared person. After years in the lab and seeing many accidents happen even to trained professionals, I advise caution of you are going into the "unknown" and ask the experts for advice.

PE

Rudeofus · Sep 30, 2011

Roger Cole said:
Gerald C Koch said:

I don't think that saying people should be careful and always know what they are doing is in any way "alarmist."

Click to expand...

And why, for the ten thousandth time, is APUG the only vBulletin site I use that doesn't allow multiquoting? Argh.

Works for me .... :munch:

Steinberg2010 · Sep 30, 2011

Surely it's far better to be informed and thus more responsible for your own safety – not to mention those around you who may unwittingly stumble across your chemicals?

~S

Roger Cole · Sep 30, 2011

Rudeofus said:
Works for me .... :munch:

How do you do it??

I can of course copy and paste and add the relevant code myself, but that's a huge PITA and I can't be bothered to do it. All the other vBulletin sites have a button for multi-quote and I can click it beside each post I want to quote and then, when I reply to the last one or hit the reply button at the bottom, all of them are quoted in my text. I can't find such a button here.

Roger Cole · Sep 30, 2011

Rudeofus said:
Works for me .... :munch:

And besides, your quote showed one inside the other, not sequentially, like this (done by copy and paste) of my own post:

Roger Cole said:
How do you do it??

I can of course copy and paste and add the relevant code myself, but that's a huge PITA and I can't be bothered to do it. All the other vBulletin sites have a button for multi-quote and I can click it beside each post I want to quote and then, when I reply to the last one or hit the reply button at the bottom, all of them are quoted in my text. I can't find such a button here.

removed account4 · Sep 30, 2011

Photo Engineer said:
I think that due to some recent posts and threads here on APUG, it became obvious that people are doing a lot of "experimenting" who have no knowledge of chemistry at all and Jerry has jumped in to help save them from possible grief.

I myself, have tried to prevent accidents when people were advised to heat chemicals in cook pots on the stove and etc..... Or, even heating chemicals in the microwave. All of these are dangerous practices that should not be done, especially for the average unprepared person. After years in the lab and seeing many accidents happen even to trained professionals, I advise caution of you are going into the "unknown" and ask the experts for advice.

PE

PE

you are funny ... "possible grief"

its like someone brewing their own silver nitrate in their kitchen
because someone on a web forum said it was easy to do ... oh yeah,
by grief you mean "accidental death" ...

to quote: mr j. frank parnell:

Radiation, yes indeed! You hear the most outrageous lies about it. Half-baked goggle-boxed do-gooders telling everybody it's bad for you. Pernicious nonsense! Everybody could stand a hundred chest X-rays a year. They ought to have 'em too. When they canceled the project it almost did me in. One day my mind was literally a-burst. The next day nothing. Swept away... But I'll show them. I had a lobotomy in the end.

i hope no one looks in the trunk !

Photo Engineer · Sep 30, 2011

There are several emulsion formulas floating around on the internet that were compiled by amateurs who know no chemistry. These in particular refer to making an acidified emulsion which uses citric acid during the make, and then which calls for ethyl alcohol to reduce bubbles or to aid in coating the emulsion. Well, this combination of Silver Nitrate, Citric Acid and either Methyl or Ethyl Alcohol is a route to disaster. Under the right conditions, it can form an explosive mixture! That is why I do not use acid in unwashed emulsions and why I use i-Propyl Alcohol.

Now, how many knew that one? Of course I am not aware of any explosions by this route, but then why take the chance. OTOH, maybe we have not heard from people who have had explosions from this reaction as they cannot report their experience to us!

PE

Gerald C Koch · Sep 30, 2011

Photo Engineer said:
There are several emulsion formulas floating around on the internet that were compiled by amateurs who know no chemistry. These in particular refer to making an acidified emulsion which uses citric acid during the make, and then which calls for ethyl alcohol to reduce bubbles or to aid in coating the emulsion. Well, this combination of Silver Nitrate, Citric Acid and either Methyl or Ethyl Alcohol is a route to disaster. Under the right conditions, it can form an explosive mixture! That is why I do not use acid in unwashed emulsions and why I use i-Propyl Alcohol.

Now, how many knew that one? Of course I am not aware of any explosions by this route, but then why take the chance. OTOH, maybe we have not heard from people who have had explosions from this reaction as they cannot report their experience to us!

PE

I don't usually read the emulsion forum so this is scary information.

Photo Engineer · Sep 30, 2011

I advise my students to avoid adding acid to unwashed emulsions and also to ensure that the Nitrate is fully washed out before they heat it up prior to coating. I advise them to use surfactants and not alcohols, although IPA is suitable as is t-Butanol to carry organics and to reduce bubbles. EtOH and MeOH are generally a NO NO.

PE

DREW WILEY · Sep 30, 2011

"Johnny was a chemist, but Johnny is no more; for what he thought was H20 was H2SO4"

RPippin · Sep 30, 2011

OK, so there is some good advice here about us non chemist fooling around with mother nature. From a more present situation, I have to say I'm not one to always take good advice. I'm careful about what and how I mix my chemicals for developer and fixer, but, and this is a big one, I have'nt always been good about wearing gloves when working with developers. My first warning that I wasn't exactly bullet proof came when I accidently got some WD2D+ on the fingers of my left hand. I washed them off right away and continued to work. A couple of days later the skin on my fingertips started cracking and peeling off!! That was nine months ago. I now always wear nitrale gloves when woking with developers, but sometimes they get into the glove on one hand or the other and I still have issues with peeling, blistering and painful skin. Sometimes even the fingers I contaminated nine months ago start cracking and bleeding again. And no, I havn't been to a dermatologist yet. I fear that I have finally hit the saturation point with toxins. I'm 64 years old, and have had a lifetime of exposure to hazards of one kind or another. Be careful out there.

Chemistry 101

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