Is there a chemist in the house?

[Calamity Jane]

(Hummm, we don't really have a category for this so we'll try "techniques"....)

I posted this on another (smaller) board but I know we have a wealth of scientific knowledge here so I thought I might reach more knowledgable folks by posting here.

I am planning to get into wet plate collodion (See, it IS LF related!) and I was reading about ethel ether and its propensity to form peroxides once the container has been opened and the contents exposed to air. The peroxides of ether are listed as a primary explosive. 8-O

Are there any chemists in the house who can speak scientifically on the storage of ether and the prevention of peroxides?

Thanks!

[Ron Marshall]

Here is a link: http://64.233.161.104/search?q=cache:jmVMEEALksEJ:ehs.ucsc.edu/Lab_Research_Safety/Pubs/Facts/Peroxides.pdf+ethyl+ether+peroxide+&hl=en

Also be very carefull to avoid flame or sparks with ethers.

[Jason Greenberg Motamedi]

www.cwreenactors.com/collodion/collodionforum/DCForumID1/1221.html (http://www.cwreenactors.com/collodion/collodionforum/DCForumID1/1221.html)

I think the best solution is a small refrigerator to store your collodion and ether.

[Scott Davis]

Also contact Rob Gibson about techniques - he is a big-time wet-plate collodion guy, and has been working with it for a very long time. He was one of the keynote presenters at the Large Format Photography Conference in Springfield, Mass this year. He's based out of Gettysburg, PA. He's very willing to share technique and information. I dropped in his studio one weekend and he was very willing to walk me through the whole process and let me watch him work. Everything from coating a plate to final fix and wash. Jason is correct about storing your chems in a fridge. Keep in mind you will need to warm them to room temperature when you are going to use them. Also make sure to work in a well-ventilated area. The ether fumes can get to you very quickly.

[Brian Vuillemenot]

...two bags of grass, seventy-five pellets of mescaline, five sheets of high-powered blotter acid, a salt shaker half-full of cocaine and a whole galaxy of multicolored uppers, downers, screamers, laughers.....also a quart of tequila, a quart of rum, a case of Budweiser, a pint of raw ether, and two dozen amyls...but the only thing that worried me was the ether. There is nothing in the world more helpless and irresponsible than a man in the depths of an ether binge...
----Hunter Thompson, Fear and Loathing in Las Vegas

[Dan Jolicoeur]

Remember the answers you gave in this thread?

http://largeformatphotography.info/lfforum/topic/502353.html#555933

[Eric Rose]

Ya gotta love Hunter S. My his tortured soul rest in peace.

[Calamity Jane]

Dan Jolicoeur: What's your point?

If you are referring to the comments about "hoarding information" I assume you mean that because I refused to fully disclose detailed information about a specific process I was developing that I am not entitled to ask any questions on this board?

If that is the case, I have a couple of words for you but they're not very nice.

[Mark Sawyer]

You sound as though you're aware of this, CJ, but a quick reminder for everyone; just as daguerreotypists used to go mad from the mercury vapors, wet plate photographers and tin-typists used to go "poof!" from the collodian and ether. (Then there was magnesium flash powder and cellulose nitrate negatives... )

[ronald moravec]

If you want to do some real damage, try mercury vapor intensification. Ether will just put you on the floor, maybe toss your cookies.

[Donald Qualls]

Jane, I, too have heard/read about the peroxide formation on stored containers of ether.

Worthy of note is *where* I've read about it: in relation to bottles/cans found on back shelves of high school chemistry or biology labs, for the most part, where a forgotten container has had literally years to sit and oxidize. If the container is well sealed, the formation of peroxide is quite slow, and if you're using the ether rapidly enough to go through a container in less than, say, a year, you're in much more danger from accidental ignition of the vapor than from formation of the peroxide.

If you see a white crust around the stopper, call the bomb squad; do NOT attempt to open, move, or dispose of the container. But if you rotate your supply you'll never see that white crust.

[Dan Jolicoeur]

Calimity; God Bless You!

[Calamity Jane]

Thanks Donald! Some good, to the point information!

I have used ether before (for specialized cleaning, engine starting, etc.) and I am well aware of the immediate hazards. It has its potential hazards but not much worse than some of the other chemicals I have worked with. It is just that I had never heard the warnings about peroxides until I read it in the MSDS data sheets.

The MSDS sheets stated that peroxides begin to form immediately on contact with air but didn't indicate the rate of peroxide accumulation or the amount of peroxide that constitutes an explosion hazard. The data sheets also talk about how to neutralize the peroxides.

My local supplier carried ethel ether in 1L bottles, so that's almost 10 batches of collodion (by both Coffer and Osterman) so I am not sure I would get thru a full bottle of ether in one year.

Definately ether will be stored out of doors in my "dangerous goods" cabinet out in the yard!

Thanks for the information guys!

[Harold_4074]

CJ--

There is a wealth of information on the Web about the chemistry and hazards of peroxide-forming chemicals, of which ethyl ether is one of the more problematic. Storage in a refrigerator is not the answer: there is apparently a temperature regime in which the peroxide reaches the saturation limit and crystallizes out, thereby disturbing the natural equilibrium between formation and decomposition. There is also an issue of minor vapor escape from the container building up a dangerous concentration inside the refrigerator, which then takes on some of the characteristics of a bomb.

I recommend the Americal Chemical Society monographs on ether hazards; many of the web sites are alarmist rehashes with little technical content. Why do I know this? Because a while ago I was helping to clear out a basement and came across a gallon jug, three quarters full, labeled in wax crayon "Waste Ether" (the jug itself still had the Merck anhydrous ether label on it). It had apparently been acquired (twenty years ago) by a gunsmith, for degreasing parts; he got it from a dental school....I suspect that the wax content from the dental work was what kept us all from being incinerated. I set the jug down---very, very, gently---and did some serious Web research before advising the owner to let the fire department deal with it ( the house was subsequently sold, intact, so I guess it all worked out).

In the case of collodion, I believe that the solvent is actually a mixture of alcohol and ether (for reasons which I think I understand but don't feel competent to explain). This is probably much less hazardous (but only with regard to peroxidization) than pure ether, so one strategy might be to stock only the mixture, without storing pure ether. (This is where you really need a chemist...)

Whatever you do, please don't abandon a gallon jug of it under the bench....

Good luck!

[Mike Gudzinowicz]

You can acquire ethyl ether stabilized with ethanol which slows peroxide
formation, or you could add 3 to 5 % ethanol to the ether (v/v). Merck sells
test strips (Merckoquant ether peroxide test strips) for peroxides. Ether
with a level of over 50 mg/l should be treated to remove the peroxides. Consult
any standard text on organic chemical purification techniques for methods, however,
the ether should be used immediately after treatment. Generally it is better
practice to buy small quantities of stabilized ether, dispose of the unused
portions of opened containers after a few months, and wash the can or bottle
repeatedly before disposal. You really don't need "pure" ether for your purpose.

Do not store ANY flammable solvents, especially ether, in a home refrigerator.
Explosion proof refrigerators are available for around $2K for a small unit. Home
models are not vented, and any spark from a switch, bulb or motor may cause
an explosion.

[fred arnold]

Let's not forget that ether fumes will also form peroxides with exposed metal in your storage cabinets/refrigerators. When I did wet synthesis we considered any can more than a few weeks old to be suspicious. Probably overly cautious, but we had other interesting chemicals around that could react with an open ether can. It also meant that if the grad student couldn't personally remember opening the can, we weren't going to trust it. Luckily most of our chemistry ran in THF or Chlorobenzene.


You can dry ether over aluminum oxide or sodium/lead alloy to prevent peroxide formation. Otherwise, never let your ether still boil down, as you'll concentrate any peroxides present as the ether boils off. I presume this warning applies to cans of it as well, so that natural evaporation will concentrate any peroxides formed. They also react poorly with strong oxidizers, so be careful with the permanganate, dichromate, and silver nitrate near the ether.


University of Alberta has a recommendation for a home-made test, but I prefer Northwestern's approach; commercial test strips, monthly checks, signed dates for those checks attached to the can, and disposed of no later than 6 months after opening. A good rule of thumb is buy as little as possible, use it immediately, and dispose of any surplus.


Politely, may I suggest you look at the book "Primitive Photography" by Alan Greene, and consider doing casein negatives instead of collodion? There are very few milk explosions in a year.

[Paul Fitzgerald]

C.J.,

You can mix 1 tbsp. baking soda with 2 oz. vinegar in a 2 qt. tumbler. When it stops fizzing, 'pour' the CO2 into the ether container, it's heavier than air and will displace the oxygen. Works well for photo chems., paints, varnish, ect. Don't pour in the liquid, just the vapor.

Have fun with it.

[Struan Gray]

Just to reiterate: do NOT store ethyl ether in a domestic fridge, or even a normal laboratory fridge. It evaporates too easily, even at fridge temperatures, and is a significant fire and explosion hazard. The saftey lecture at the lab where I did my PhD always started with an open bottle of ether being put into a fridge (outside on the lawn). At the end of the lecture the door would be opened by pulling on long string and there was always a satisfying bang as the switch for the light sparked and ignited the ether fumes. You wouldn't want to open that door with your hand.

There are specialised fridges for the storage of flammable solvents, but for ethyl ether an outdoors metal cabinet will suffice.

[David Beal]

Jane, do NOT buy gallon bottles of ether. First, what you're buying is not anhydrous, even if it claims to be. It might even be "solvent grade" ether, which is not very clean. Second, glass breaks. A gallon of ether produces a massive amount of vapor, and it dissipates quickly; it also finds ignition sources quickly.

Buy your ether in metal containers, containing less than 1 liter. These should be marked "ACS Reagent Grade." They are sealed with soft metal, and have a plastic overcap.

CAREFULLY puncture the metal cap with a NONSPARKING metal tool, and cap immediately with the overcap. Then, pour out what you need, and use it IMMEDIATELY. All your work should be done in a well-ventilated area, and the ventilation equipment should be certified to be safe to use with flammable vapors. Electrical switches and lights should also be explosion rated.

Your work should not involve any metal trays or tools. Use plastic or glass ONLY.

When you finish your work, take the waste ether and the can of ether outside and pour all the ether into a large tub of water. The ether will evaporate quickly. Fill the can up (even if you used up all the ether) with water, and pour the contents into the tub. Repeat 3 times. Fill the can up with water one more time, and let it sit outside until the water evaporates.

Peroxides are a dangerous and constant problem with ether.

As noted, DO NOT store ether in any kind of refrigerator, even if it in a sealed metal container. Make sure you DO NOT do any work in a basement or area where there might be a water heater or furnace; a pilot light or spark ignitor could cause an explosion.

In my old lab, we worked with ether in fume hoods. The lights in these hoods were enclosed in vapor-proof glass, and the hood was fitted with explosion proof switches.

If this seems like overkill, it isn't. Until you've see how easily an ether explosion can occur, you won't believe it. The old photographers who made plates and didn't get burned up or blown up were incredibly lucky. You may not be.

As a Ph.D. student I worked with Hydrogen Fluoride and Metal Fluorides and made acids that were one hundred million times more reactive than concentrated sulfuric. I synthesized carcinogens and chemicals that were neurotoxic, and studied their reactions with this superacid. I was always very, very careful.

But when it came to using ether, I was fanatically careful.

Good plating.

/s/ David Beal

[Joe Smigiel]

Mike Gudzinowicz stated:

"You can acquire ethyl ether stabilized with ethanol which slows peroxide formation, or you could add 3 to 5 % ethanol to the ether (v/v)... Generally it is better practice to buy small quantities of stabilized ether, dispose of the unused portions of opened containers after a few months, and wash the can or bottle repeatedly before disposal. You really don't need "pure" ether for your purpose."

Whew. The ether-peroxide storage problem sounds scary.

I've skimmed a couple collodion manuals looking for some reason to keep the pure ether around and the only thing I can find is out of John Towler's The Silver Sunbeam regarding the formation of ridges and undulating lines on the finished plate:

"These are caused by the too great consistency of the collodion... The remedy is to add sufficient ether to cause the collodion to flow smoothly, easily, and uniformly over the plate."

So it sounds like there is little use for the ether after the initial mixing of the working salted collodion formula, certainly not enough for me to keep it stored about. Most other remedies involve adding more ethanol or an acid to alter the properties of the working solution. Based on this it sounds like it is best to mix the working solution and then safely dispose of any remaining ether instead of attempting to store it. It also would appear one needs to initially acquire less than half a volume of ether compared to the plain collodion amount.

A typical formula for a working wetplate collodion is:

part A:
1.5 gm cadmium bromide dissolved in 3ml distilled water + 2 gm potassium iodide + 100ml pure grain alcohol (190 proof ethanol)

part B: 120 ml plain collodion +50ml ethyl ether

To make a working solution part A is added slowly to part B.

So, if the percentage of ether in a plain collodion is assumed to be about 70 % (from an MSDS) and about 25% ethanol, the working solution above figures to contain roughly about a 49% ether: 47.6% ethanol mix (134 ml ether and 130 ml ethanol in the 273 ml working mixture). This is a much larger percentage than the 3-5% alcohol ratio you suggest adding to the ether to stabilize it. It sounds like such an amount of ethanol would perhaps greatly slow down the rate of peroxide formation making it much safer to store and perhaps giving the opportunity to use up the small amount of mixed chemicals within a years time. If I'm reading you correctly, the mixed working solution of collodion would be much safer than having the separate chemicals in storage. Can you comment on that?

Also, what do you consider a "small amount" of these chemicals?

What do you recommend for storage of the mixed working solutions of collodion ?

Thanks Mike and David, et al, for the advice and comments.

[Calamity Jane]

Thanks David - good post!

My chemical supplier is the same one that supplies my company's Chem Lab (Manitoba Hydro) and the ether is reagent grade. I am sure it is sold in metal cans (since the suppliers don't like to blow themselves up either!) but I am checking with the supplier on that, whether or not is has been "stabalized", and about obtaining smaller quantities.

(Just got an e-mail from them - it IS available in smaller quantities, "anhydrous ACS reagent grade", stabalized with "BHT" - now I gotta find out whatinheck "BHT" is!)

As for working with the ether, I intend to do my initial mixing outside in the wide open spaces. Since the ether gets mixed with equal parts alcohol, I may do that mix right off the bat and store the ether/alcohol compond - I am checking with our senior chemical technician to see what effect that would have on the formation of peroxides.

I am building a "chamber" for the darkroom to contol vapours. It is actually a plywood box with a plexi windshield, holes to stick your arms in, with plexi windows on top so there is no need for electricals inside the box. (Looks like the chambers they use in the Level 4 Bio labs!)

I have installed a 4" exhaust duct from the darkroom directly to the outside and equipped it with an 80 CFM fan with a shaded pole motor (no brushes, no sparks, no source of ignition). This will connect directly to the chamber. With the lower explosive limit of ether being 1.9% I am going to make sure there's a steady wind blowing into the chamber and out the exhaust!

I am also going to add a BIG dry-chem fire extinguisher to the darkroom and a box of impervious disposable gloves! I even thought about a respirator (bottled air) but figured putting the exhaust fan on a UPS (in case of power failure) is probably more logical.

Paranoid? Who's paranoid? I didn't get to be 56 years old working in the sciences by being flippant about materials! If I do one day blow myself up, I want the explosion to be heard for 500 miles! ;-)

[Bob Phipps]

The answer about using a small refrigerator is out of the question. Small home frig. for keeping colas and the like has a major flaw - it is not spark proof. Laboratory refrigerators have special wiring, spark proof insulation, and ventilation for removal of accumulated evaporates before opening the door.

Working in genetic research in college, I used anethitizing either [ not ethyl, but similar properites] which we stored out of the building. We filled our fruit fly sleep jug in the safe building with .1 mL of either and then placed it on ice and came back to the lab. Thankfully by my junoir year a new product was developed that did not use either.

It is a wonder that early photography survived without the knowledge of the explosive dangers of the components of many of the solutions used. Worst of all was the flash powder made from "Lycopodium" spores. Hard to look at ground pine and think of it as explosive. Professor of Plant Physiology class took us to the AROTC rifle range to demonstrate its use.

[Kirk Keyes]

BHT - Butylated Hydroxytolulene, commonly used as a food preservative/antioxidant. See:

http://chemistry.about.com/library/weekly/aa082101a.htm

[Harold_4074]

From post above by Calamity:

"I am building a "chamber" for the darkroom to contol vapours. It is

actually a plywood box with a plexi windshield, holes to stick your arms

in, with plexi windows on top so there is no need for electricals inside

the box. (Looks like the chambers they use in the Level 4 Bio labs!)

I have installed a 4" exhaust duct from the darkroom directly to the

outside and equipped it with an 80 CFM fan with a shaded pole motor (no

brushes, no sparks, no source of ignition). This will connect directly to

the chamber. With the lower explosive limit of ether being 1.9% I am going

to make sure there's a steady wind blowing into the chamber and out the

exhaust!"

The idea is right, but there are a few things to keep in mind:

1) 80 CFM of air (if you actually have that much flow) will bring through your work area all of the dust, lint, etc. contained in 80 cubic feet of air, each minute. There is a class of aerosol collectors referred to as "plate impactors"; you may find that you have constructed one! Inlet filtering, of course, is the answer, but it will likely reduce the flow substantially.

2) Even a fairly small chamber can be hazardous if you are standing next to it and an explosion of any size occurs inside. (Say, some ether vapor ignited by static electricity). It takes only a few PSI of overpressure to accelerate a plastic window to a high enough velocity to cause some real unpleasantness. You might consider "blowout walls" of plastic film on three sides, supported by a light weight grid to resist the negative pressure developed by the fan.

3) A shaded pole motor is sparkless, but any fan can lead to static discharges caused by tribolelectricity (rubbing of dissimilar materials, such as dust and ductwork). If the flow is high enough that an ignitable concentration is never reached, then all is well. However, you should consider the worst case (a spilled bottle?) and plan accordingly. If the fan would take it, a water mist nozzle in the duct, right at the outlet of the work chamber, might be good insurance. In any case, resist the temptation to use PVC pipe or flexible plastic ducting, and electrically bond the pieces of the system.

[Calamity Jane]

Good points Harold! Thanks.

1) Dust. My new basement darkroom is remarkedly dust free (compared to any other room) but a nice intake filter on the chamber is a good idea.

2) Explosion. I had considered vapour barrier sheeting for the sides but didn't know how to stop it from sucking in. You, my friend, have hit on an elegant solution! Black builder's plastic for the sides.

3) Fan/duct. The duct work is all galvanized steel, electrically connected to ground and bonded together. The fan is all metal as well. As to static electricity, I will have to test that this winter when the humidity gets down near single digits. I suspect, with the amount of grounded metal (the ducting) and the low dust levels, there shoudn't be any static, but I will have to verify that.

I don't plan on handling raw ether in the chamber, only mixed collodion, but I will verify the air flow when it's done to know for sure how much ether evaporation is tollerable.

If it wasn't for these darned COLD Manitoba winters, I could work outside! Most chemicals though don't seem to like temperatures below -30 ;-)

[Donald Qualls]

Jane, I think the suggestion for an intake filter was for the entire darkroom -- to prevent the fan exhausting the chemical box from drawing in all sorts of crap that you'll then be constantly having to remove from conventional negatives, lenses, prints, etc. Better even than a simple filter would be a much larger-rated intake fan with filter, so the darkroom as a whole is very slightly pressurized -- then leaks will blow, rather than suck (and a leak that brings in dust really does suck!), and the fan exhausting the box won't be working against a pressure differential.

My experience suggests both ethanol and ethyl ether remain liquid and easily handled at -30 F, but that doesn't mean photographers work well at that temperature.

I wonder, occasionally, why collodion photographers haven't changed to working with nitrate lacquer, aka glider dope or nitrate dope -- it's almost identical to collodion, but the thinner contains neither ether nor acohol, isn't prone to peroxide formation, won't anesthetize the user (or at least not the way ether can), and is much less flammable than ether. There may be good reasons this close relative to collodion isn't used -- but I don't know what they are. Seems to me it might be worth looking into -- glider dope and its thinner are both a great deal cheaper than collodion and ether, too.

[Struan Gray]

Handling volatile solvents outdoors in extreme cold can give you frostbite. Loosely-fitting gloves you can shake off quickly are a standard precaution.

If you're really unlucky, you'll have cold burns to your hands, and flash burns to your face. :-)

[Harold_4074]

"My experience suggests both ethanol and ethyl ether remain liquid and easily handled at -30 F, but that doesn't mean photographers work well at that temperature."

Hmmm...ethanol is a pretty good antifreeze, but maybe handling ether while maintaining a high enough blood alcohol level to keep you from freezing at -30F wouldn't be such a great idea...

Regarding filtered positive-pressure air for the entire darkroom: this is actually a great idea if it can be pulled off, but I was actually referring to all of the lint, cat hair, etc. that would otherwise end up either as dust bunnies in the corners or in the lint trap of the clothes dryer. I would probably think in terms of a good, high-flow filter for the box, and some elastic-cuffed sleeves to seal between my wrists and the box wall (sort of like glovebox gloves, but without the loss of touch and dexterity). Collodion is a traditional wound dressing (liquid Band-Aid) so I wouldn't worry too much about working barehanded and the sleeves would keep all the crap on my clothes from winding up on the plates.

[Harold_4074]

Allow me to add: before someone becomes upset over the notion of working barehanded with wet-plate coating chemistry, I should point out that it may indeed contain unhealthy things not found in wound dressings (like cadmium bromide, perhaps).

On the other hand, anyone without the competence and/or sense to observe standard laboratory hygiene practices (washing hands, not tasting the chemistry, etc.) probably shouldn't be in a darkroom anyway.

(I have no reservations about Calamity Jane's ability to do these things safely---I checked out her website, and read about some of her other hobbies...)

[Mike Kovacs]

I didn't read the entire thread, so apologies if I'm repeating information. I am a chemist by training and run a research lab.

1. We are required to test our diethyl ether for peroxides yearly. The cans are dated when opened so we know when. Normally, we would use the entire volume up before the year elapsed. There is another flavour of ether that needs to be tested every 3 months that we do not stock.

2. Someone suggested to store diethyl ether in the refridgerator. There are explosion proofed refridgerators used in labs to do this. Not a good idea to do this at home folks, unless you physically modify it to locate the thermostat OUTSIDE the fridge. You could easily cause a nasty explosion.

My advice is to work in an extremely well ventilated area, think long and hard about any possible ignition sources (e.g. electric devices) and buy the ether in small bottles so you use them up well before peroxide formation becomes and issue.

[Calamity Jane]

Thanks for the additional comments gang.

Regarding handling ether at low temps - just so folks are aware - or any other liquid that evaporates quickly can cause frost bite if spilled on the hands. The cold liquid not only steal warmth from the skin immediately but the evaporation also has the effect of cooling the skin below the ambient air temperature!

(I use gasoline for cleaning some particularly dirty mechanical parts. The gasoline is stored in an old fridge (not plugged in) on the north side of the shop and I have a small bench outside specifically for parts cleaning. I learned the hard way how fast liquid at -30 can steal heat from your hands!)

I don't know how it will work out but I intend to wear gloves while handling wet plate chemicals (as much as possible). I hope to avoid the discoloured fingers! I'll also wear gloves to avoid transferring the chemicals to my clothing, etc. (and my cigarettes!)

Mike: It's good to know that labs aren't worried about peroxide formation until the ether has been un-corked for 1 year. Us amateurs should be safe if we allow 6 months before disposing of any unused ether.

Very interesting thread - thank you all!

[Mike Kovacs]

I think 1 year is still OK. In testing in 1 year intervals, I have never had it come back positive.

[Mike Kovacs]

I think 1 year is still OK. In testing at 1 year intervals, I have never had it come back positive.