John, Yes very unpleasant indeed. I'm using a respiratory and I'm gloved when handling it. The darkroom is very well ventilated with a good filtered fresh air supply. So I'm pretty comfortable working with it. You are also correct as to hardening the sizing. My question is.. what is the sediment? If it not suppose to be there then should I even consider using it? ThanksNo, you shouldn't have anything at the bottom. Formaldehyde is actually a gas at 20 deg C, you have 37% formaldehyde solution, sometimes called Formalin (a trade name). The fumes are dangerous as well as unpleasant so don't try and filter it, certainly not outside of lab conditions. I'm guessing from you posting in the alt process forum you're using it to harden gelatine sizing. I would pipette off what you need as and when just leaving the sediment.
Michael, I'm using a double cannister half face respirator. But I didn't realize that there are special cartridges for formaldehyde and that they last only 3 hours.The cartridges that are in mine are: R51A chemical cartridge for organic vapors. The paper work that came with the cartridges is long gone so I'm not sure if they are rated for formaldehyde gas so I'll replace them. Thanks, RobertRobert,
Go to the nearest tool rental place (United Rentals, or whatever you have near you) and get a good half face respirator and also the cartridges that are suitable for formaldyhide if you don't have one already. The cartridges are good for about 3 hours. I write on the cartridge the total time I have it on so I know when to replace.
As John says, formaldehyde is a gas, so the sediment is not what you want, and it is probably nothing to worry about as long as there isn't too much of it. Pour off the top or pipette from the top and you'll be fine. I poured a bit into a bottle with a dropper and use it that way.
One time using that stuff with a mask will convince you to get one...
---Michael
Robert,
Go to the nearest tool rental place (United Rentals, or whatever you have near you) and get a good half face respirator and also the cartridges that are suitable for formaldyhide if you don't have one already. The cartridges are good for about 3 hours. I write on the cartridge the total time I have it on so I know when to replace.
I wonder whether a half face respiator provides adequate protection.
A few years ago I met a Dutch Leica collector who used to work in a hospital, where he suffered overexposure to formaldehyde gas. This caused such damage to his eyes that he has become an invalid. I would be extremely careful with this stuff.
Gerald, I just spoke with a scientist at Fisher Scientific and he said the exact same thing, that formaldehyde polymerizes to a substance known as paraformaldehyde which will never go back into solution. He said that this is usually accelerated by improper storage. A warehouse where the temp has dropped below 20C (I think that was the temp he cited) will cause this almost immediately. I asked what he would recommend and he said "dump it, it is no longer a 37% solution because of the polymerization" I called Science Lab Chemicals and Laboratory Equipment Co. in Houston, Texas and they refuse to make good on the purchase. They also didn't ship it Hazmat like they should. And some of the formaldehyde leaked around a cap that wasn't properly sealed.(no inner seal inside the cap). It is scary to think these people are handling these types of chemicals so unprofessionally. I guess I'm out the price of a liter of formaldehyde. But just a warning to others not to buy from these people. Fortunately here in the small town where I live the local pharmacist said he will order the formaldehyde for me.After a period of time the formaldehyde in solution polymerizes to a substance known as paraformaldehyde which is insoluble in water. This is the sediment that you have noticed.
When I was in high school most everyone had to take biology and dissect a dead frog. The classroom reeked of formaldehyde, bo one died. Unfortunately, today, everyone is afraid of chemicals (stage director, please insert creepy music here). Nothing is kept in perspective.
The last MSDS that I read said that formaldehyde was a possible carcinogen. While it is irritating in higher concentrations, it should be safe for occassional use for photographic purposes such as hardening baths.
I wonder if the EPA ever did a followup study on morticians to see if there was any increase in cancer with members of that profession.
Kerik, That may be a good idea. I went and dug out the box and paper work to make sure I didn't miss anything. The formaldehyde was shipped without a hazardous materials shipping paper. It was shipped UPS ground and the only other identifying label is a small blue sticker that says "consumer commodity ORM-D"Robert,
If you want to push it with Science Lab Chemicals, you could let them know you expect a full refund otherwise you will report them to the shipper for improperly shipping hazardous materials. If they're smart, they'll avoid the hassle and return the money you are owed.
Whether something must have hazmat shipment depends on the substance and the amount. For example, one pound of sodium hydroxide (lye) does not required a permit while two pounds does. However, you can order as many pounds as you wish provided each pound is in its own package.They also didn't ship it Hazmat like they should.
Michael, You are probably right. It is not worth the hassle although I would like my money back. There is about an 1 1/2" of sediment in the bottom of a 1 liter bottle. Is this a lot? I don't know. I have nothing to compare it to because I've never seen this before and all the formaldehyde I have seen has been water clear. It is nice to get a lesson in polymerization but not at 60.00 a lesson. With that much sediment I'll just have my pharmacist order me some. I'll feel more comfortable using formaldehyde that I know is good. No sense in introducing any future problems into the process by using a chemical I'm not sure about. So I'll just chalk it up to experience. PE, I'm sure what you're saying is true. But I'm using such small amounts that a liter will last a very very long time. If I was using larger quanities then I may consider trying mixing and reheating. But even though I have a pretty good ventilated darkroom I wouldn't feel comfortable reheating formaldehyde with the family upstairs. The risk outweighs the costs. Thanks guys, RobertRobert,
Unless there is a lot of sediment, the reduction in solution percentage is probably of no importance for hardening gelatin. Rather than fight with the supplier, I would try it, and if it works fine, then don't bother.
There's too many things in the world to get worked up over, and this one doesn't sound like a problem worthy of the hassle.
---Michael
I'll send you a PM with some info I found on formalin...
I'll never use glyoxol again. Works fine if it is very fresh, but as the bottle ages, it causes the gelatin to yellow unacceptably, regardless of the time delay between sizing and printing the first layer.
Jeremy, unless you can't adequately handle it, I would dispense with the glyoxol and go straight to the formalin. There are some sources out there for it, but I am not going to publicly point people to them as it is a chemical used in the grug trade (at least I've been told) and is a SOB to boot, so I don't want people to casually get their hands on it.
---Michael
A 2.5% solution of gluteralhyde works great, never yellows, and leaves the paper smooth as a babies butt.I'll never use glyoxol again. Works fine if it is very fresh, but as the bottle ages, it causes the gelatin to yellow unacceptably, regardless of the time delay between sizing and printing the first layer.
Jeremy, unless you can't adequately handle it, I would dispense with the glyoxol and go straight to the formalin. There are some sources out there for it, but I am not going to publicly point people to them as it is a chemical used in the grug trade (at least I've been told) and is a SOB to boot, so I don't want people to casually get their hands on it.
---Michael
A 2.5% solution of gluteralhyde works great, never yellows, and leaves the paper smooth as a babies butt.
That's not been my experience with it. I use very small amounts and keep containes closed.And, it smells up the DR as bad or worse than formalin. There is a law suit in Australia over glutaraldehyde.
PE
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