Nickel Toxicity
WARNING: The steps described in this paper can produce fine nickel powder, which can be toxic. The procedures in this paper should be performed in properly equipped laboratory, in a glove box or other enclosure. Disposable gloves and masks should be worn when handling these materials. They should also be worn to avoid contaminating the materials. Only people skilled in the art should attempt to replicate this experiment.
Very sensible advice Jed. Some people are very allergic to Nickel, so allergic that even stainless steel can affect them. Dennis Letts pretty much avoids working with Ni since it made him sick in the past. It doesn't seem to bother me at all, which is lucky, but I have acquired a sudden allergic reaction to cyanoacrylate adhesive (gorilla glue) after years of using it without problems- so one should always take care with potentially powerful allergens, since you never know when they might bite yer ass.