Re: About sizing gum: Hey -- READ THE LIST !!!
On Wed, 19 Aug 2009, phritz phantom wrote:
i saw this mentioned before, among others by sandy king. when i first ordered the chemical, i looked around, if there was any info available on the toxicity, precautions when handling... etc. but there wasn't much info available. to my understanding (from what i was able to find out), chrome alum is a chrome (III)-compound, which are not as toxic as chrome (IV)-compounds (such as the dichromates). there aren't any hazards mentioned on the english and german wikipedia pages. but i don't know, if there really aren't any, or if just nobody added them yet.To date, in my experience, only one of the alums gets a pass (tho to save my soul, I couldn't say which)... Meanwhile, tho most of what I know about the topic is word of mouth, or conventional "wisdom," which we all know is a frail reed, it occurs to me that in the long ago Mike Ware wrote something about chrome in water turning into stage 3, which is, he said, harmless... (That of course is a garbled version and not to be quoted.)
HOWEVER, I do have a better idea about glyoxal, as by the time it gets into the water, it's reduced (or like that), plus we never got the warnings about it we got about alum. Also, I've used glyoxal for years and can still, casually, not even trying, bite heads off. (If I find that book about health hazards in photography, I'll look up alum, tho that lady can make gelatin and gum arabic sound like death bombs.)