I am concerned that all those responding so far have accepted the possibility of this reaction being caused by concentrated sulfuric acid or iodoacetic acid, or a combination, without commenting on the very long delay between the putative skin contact and the appearance of the blistering without intervening itching or other issues, and the extended period of expansion of the blustered skin area beyond the putative area of exposure.  I was not aware that sulfuric acid alone exhibited such a long delayed response with extended expansion of the responding area – especially when, presumably, at least initially, the student had washed her hands.

I have not dealt with iodoacetic acid, but a cursory search reveals it to be highly corrosive, especially to the eye, even via systematic transport. But I have found nothing that suggests a delayed response.

My first thought on reading the request was that something like HF was involved, but the nature of the blistering as described does not seem to be consistent with HF burns.

A closer review of other potential exposures, occurring after the procedures described, may be appropriate.

Peter Zavon, CIH
Penfield, NY

PZAVON**At_Symbol_Here**Rochester.rr.com

Howdy folks,

Asking this question on behalf of a colleague from another university (so if there are follow-up questions, there may be a communications delay in answering them):

What kinds of delayed reactions are known for iodoacetic or concentrated sulfuric acid?

Here’s the background:

A graduate student was working with concentrated sulfuric acid to acidify wastewater (wastewater treatment plant effluent) samples, and spiking them with iodoacetic acid (small quantities, since it was a spike). An experienced student, who had done this before , she was wearing nitrile gloves (the typical disposable type). To the best of her knowledge, she had no skin contact with the chemicals she was using and used proper glove removal technique.

Approximately a day or so later, she noticed a blistered looking patch on the back of her hand, near the joint of the thumb and first finger bones – about the size of a nickel. It spread, and by about four days after the presumed exposure, covered approximately half of the back of the hand. On-campus medical referred to a more experienced doctor, who ended up referring the student to a hospital with burn expertise (including chemical burns). The campus EH&S felt the response was due to the sulfuric or maybe the iodoacetic acids; the hospital agreed it looked like a chemical burn. The assumption is that acid penetrated the gloves or fell off the gloves onto skin during removal.

Treatment ended up including cadaver skin transplant; the student seems to be recovering well and doing fine. However, all involved would like a better understanding of what might have happened.

Information related to the question above, or other ideas as to what else you might consider checking for possibilities, is welcomed.

Thanks,

Sue

___________________________________

Susan D. Wiediger, Ph.D.

Professor of Chemistry

Southern Illinois University Edwardsville

swiedig**At_Symbol_Here**siue.edu          618-650-3088

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