Negs and alcohol

Andy K · Nov 10, 2008

Please be careful when using Isopropyl Alcohol. As well as being a Group 1 carcinogen it carries many other health hazards: http://www.osha.gov/SLTC/healthguidelines/isopropylalcohol/recognition.html

Aurum · Nov 10, 2008

spb854 said:
AAHHH....phenolphthalien.

What fun I had with that when I was a chemistry major. (Decided to go into pharmacy later on.)

It also dissolves in Bacardi 151 rum......just to let you know.

For those that don't..........it WAS the active ingredient in Ex-Lax.

Steve

And still licenced as a vetinarian grade lax.

Photo Engineer · Nov 10, 2008

Andy K said:
Please be careful when using Isopropyl Alcohol. As well as being a Group 1 carcinogen it carries many other health hazards: http://www.osha.gov/SLTC/healthguidelines/isopropylalcohol/recognition.html

Andy;

Please re-read that. It says that there is insufficient evidence for carcenogenic activity of the alcohol, but the manufacturing process produces conditions which can lead to sinus cancer via inhalation.

It seems clear to me from just that reference that IPA is ok if purified, but during the manufacture, workers are exposed to carcenogenic fumes.

Bottom line is that IDK what the article is trying to say other than it acts pretty much like ethyl alcohol on the human body only more so. That is to be expected from the metabolites and the different structure.

PE

eclarke · Nov 10, 2008

Photo Engineer said:
Yeah, the fumes are not good for you and IPA is flammable.

Take care.

PE

My Dad was a chemist and years ago (late 1940s) one of his co workers was setting up an procedure which required 2L of pure alcohol. He broke the flask, wetted his shirt, inhaled fumes and then went to the hallway to smoke, lit up and perished on the spot...Evan Clarke

Photo Engineer · Nov 10, 2008

Evan, very sad story. I'm sorry that such an awful thing happened.

I was pouring Methanol from a 4 L bottle into a flask when a spark ignited it and a flame about 5 feet long shot out of the bottle with a roar. Then it went out. I was lucky!

BTW, heavy angora sweaters and similar fuzzy things are banned at Cape Canaveral, as they tend to adsorb oxygen. During fueling with LOX, a sweater can become saturated with excess oxygen. A person left a pad to go for a smoke and when he lit up, he literally exploded. That was in the very early days, but they lectured us on that event and told us sweaters were among prohibited items.

So, accidents happen, and I always try to be safe. You should see my lab coat and my sweat shirts. Very holy artifacts! I show them in the DVD.

PE

eclarke · Nov 10, 2008

Photo Engineer said:
Evan, very sad story. I'm sorry that such an awful thing happened.

I was pouring Methanol from a 4 L bottle into a flask when a spark ignited it and a flame about 5 feet long shot out of the bottle with a roar. Then it went out. I was lucky!

BTW, heavy angora sweaters and similar fuzzy things are banned at Cape Canaveral, as they tend to adsorb oxygen. During fueling with LOX, a sweater can become saturated with excess oxygen. A person left a pad to go for a smoke and when he lit up, he literally exploded. That was in the very early days, but they lectured us on that event and told us sweaters were among prohibited items.

So, accidents happen, and I always try to be safe. You should see my lab coat and my sweat shirts. Very holy artifacts! I show them in the DVD.

PE

My dad said the man's lungs incinerated instantly, he was gone in microseconds. Chemical safety is important, alcohols, acids, strong bases etc. can really do some damage quickly leaving no time to think especially in closed up little darkrooms. I am pretty safe but don't have a chemical hood with exhaust, I inhaled a small (surprisingly small, no mask) amount of pyrogallol one time and learned my lesson with dry chemicals.

totalamateur · Nov 13, 2008

Another way to get the H20 out of everclear, rather than use benzene, is to get a desicant pack from academy and pour the granules into the alcohol. The desicant is more hydroscopic than the ethanol, and removes the water. This is how a buddy of mine made 95% (cheap) ethanol into Histological grade (not as cheap) for his college chemistry experiments. For photo chemicals, I'm not sure how much, if any, of the dessicant would disolve into solution, and then spot your negative. The dessicant is refreshed by decanting the ethanol, then baking the crystals for several hours at a little above boiling.

Paul Verizzo · Nov 13, 2008

eclarke said:
My Dad was a chemist and years ago (late 1940s) one of his co workers was setting up an procedure which required 2L of pure alcohol. He broke the flask, wetted his shirt, inhaled fumes and then went to the hallway to smoke, lit up and perished on the spot...Evan Clarke

Wow, that's sad! A genuine Darwin moment, for sure.

I was taking HS chemistry, two ditzes used the lab bench behind mine. One day I smelled gas. I turned around and she was about to strike a match, obviously not having shut the gas off of the Bunsen burner when it blew out.
Since the "wall" next to us was all glass, it could have been a spectacular moment.......

Paul Verizzo · Nov 13, 2008

totalamateur said:
Another way to get the H20 out of everclear, rather than use benzene, is to get a desicant pack from academy and pour the granules into the alcohol. The desicant is more hydroscopic than the ethanol, and removes the water. This is how a buddy of mine made 95% (cheap) ethanol into Histological grade (not as cheap) for his college chemistry experiments. For photo chemicals, I'm not sure how much, if any, of the dessicant would disolve into solution, and then spot your negative. The dessicant is refreshed by decanting the ethanol, then baking the crystals for several hours at a little above boiling.

Pretty brilliant! Cheap stuff at Walgreens and those hobby big box stores for drying flowers.

Paul Verizzo · Nov 13, 2008

Paul Verizzo said:
Pretty brilliant! Cheap stuff at Walgreens and those hobby big box stores for drying flowers.

I meant to include in that post that means you can buy 90% ethyl rubbing alcohol for less than $2, dry it, and have a fairly pure product except for the denaturing product.

Photo Engineer · Nov 13, 2008

Drying with dessicant does not work well unfortunately. I've forgotten all of the reasons over the years, sorry to say, but that was covered in one of our classes on azeotropic distillation way back when.

If it did work, absolute alcohol would be made that way.

PE

Negs and alcohol

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