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Sensitization, Part II

November 14, 2011

I read MSDS info (Material Safety Data Sheets) like they were religious documents. It feels like it should go without saying that safety counts for a lot. But, actually, it probably can't be said too often. Everyone needs to know and understand the risks of handling chemistry — and everyone will make a different valuation. I wouldn't use some of the chemicals in published emulsion recipes if a Nobel Prize in Photography were on the line — just as I wouldn't make collodion wet plates if it were the last photographic process on the planet. I garden organically and I think Kool-Aid should come with a health warning, but I work with silver nitrate almost every day and I'm a devoted gum printer, which requires the infamous Chrome VI.

This weekend, I received an excellent admonition/suggestion from Martin Angerman. The reminder to mention safety and working responsibly is very greatly appreciated. Thank you, Martin.

Following Martin's advice is a list of books on sensitization.

From Martin:

"I would recommend extreme caution with the list of sensitizing chemicals in your recent bits and pieces column. My red flag went up when I saw acridine orange on the list. This is a dye that is used for its ability to slip in between the base pairs of DNA. It should be treated like a confirmed carcinogen/teratogen. Out here in California, it requires special hazardous waste handling, for any amount, even the little trips that would come from emulsion making. Most all of the other chemicals would be highly suspect, particularly those with fused rings.

I recommend a special flag that any potential user check the MSDS before ordering. This stuff can be just as dangerous as mercury and cyanide salts.

... I would even treat any gloves used to make up stock solutions as hazardous waste, themselves.

My recommendation for anyone doing the sensitization dye work would be to have all scraps, drips, etc kept in a break-proof bottle. Gloves with concentrated dyes can be kept in Ziploc bags (preferably double-bagged. Large chemical suppliers make PVC coated glass bottles. They are much less likely to spill out contents, when dropped. Label it with all of the nasties that go into it. Most cities have a household hazardous waste event. They will usually take things that are under one gallon, without too many questions. The local environmental health people here in Ventura are very delighted that I call, and work all of this stuff out, ahead of time. Also, I would keep dichromate separate from dyes, etc.

Here is a link to California's Proposition 65 list of cancer/reproductive harm related chemicals. The list of chemicals can be downloaded as either a PDF or XLS format. This should be considered as a list of "red flag" stuff. It is a minimum, not an exhaustive list.

There is also a "arts and crafts" section, which may be useful for anyone doing or planning workshops.

Take care,

Martin Angerman"


A Partial LITERATURE LIST in Chronological Order

1) Photographic Emulsion Technique, by T. Thorne Baker, American Photographic Publishing Co., 1941 and 1948.

2) Fundamental Mechanisms of Photographic Sensitivity — Proceedings of a Symposium held at the University of Bristol in March 1950, Butterworths Scientific Publications, 1951.

3) Photographic Emulsion Chemistry, by G.F. Duffin, The Focal Press, 1966.

4) The Theory of the Photographic Process, chapters 11 and 12, by C.E. Kenneth Mees and T.H. James, The Macmillan Company, 1966.

5) Spectral Sensitization, by Hans Meier, The Focal Press, 1968.

6) SPSE Handbook of Photographic Science and Engineering, edited by Woodlief Thomas, Jr., Wiley-Interscience Publication (John Wiley & Sons), 1973.

7) Introduction to Photographic Theory — The Silver Halide Process, by B.H.Carroll, G.C. Higgins, and T.H. James, John Wiley & Sons, 1980.

8) Photographic Sensitivity, by Tadaaki Tani, Oxford University Press, 1995.

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