On Mon, 26 Jan 1998, Richard Sullivan wrote:
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> I don't see any practical way to do tray developed pyro without wearing
> gloves, unless your goal is to look like an old timey photog and risk life
> and limb in the process. The nitrile gloves sound like a good bet, though I
> would not be too prone to lose any sleep over using regular latex gloves
> for developing a 7 minute pyro run. On the other hand, at that price, why
> not get a 100 box of the good ones.
Appended to Sullivan's message was another from Larry Gustafson, which I
also include...
But my questions first:
1. what is nitrile?
2. Does "the good ones" mean the box of 100 for $15 mentioned below?
3. I gather from recent posts that few people now do pyro development in a
tray.... or have I leapt to a conclusion?
4. What is phenolic?
Judy
message from Gustafson re gloves for pyro:
> >Pyro is extremely toxic and not just any glove will work. Latex gloves may
> >be permeable to the pyro. Nitrile gloves may work better. Below are some
> >comments from another list server on using gloves with phenolic based
> >developers (note: the writer had not tested pyro):
> >-----------------
> >......... Best Glove had no data on photographic chemicals in their
> >files. They did NOT recommend the use of latex gloves with developers such
> >as pyro. Their first choice would be their N-Dex nitrile gloves for short
> >term intermittent contact. I have run a check on the N-Dex 7005 (4 mil
> >nitrile industrial disposable) glove using a Q&D test procedure that they
> >recommended for screening using Windisch modified catechol developer (and
> >the catechol stock solution) and did not observe any break-through after 4
> >hours. Looks like these gloves will work.
> >
> >Best has a web site (www.bestglove.com) with a listing of distributers of
> >their gloves. The N-Dex 7005 list for about $15.00/box of 100 in Fischer
> >Scientific.
> >
> >The test procedure that they suggested was to cut off a glove finger, turn
> >it inside-out, fill with the test solution, and then close with a paper
> >clip. Hang the filled glove finger in a 35mm film container that contains
> >some distilled water and see if the pH of the water changes with time. If
> >something is permeating the glove, the pH of the water should change. It is
> >suggested to run a distilled water control to eliminate changes in water pH
> >from the glove material.
> >
> >Following this procedure, the working strength Windsich developer (strongly
> >basic but not measured - sodium hydroxide is the base) and the DI water
> >control did not change the pH of the water on the outside (stayed at 5.5)
> >for at least 4 hours. The catechol stock solution (pH 8.5) also did not
> >change the water pH over about 2 hours and the test is continuing overnight.
> >
> >Hopefully this will be one way to minimize exposure to pyro and other
> >phenolic based developers.