toxicity chrome alum?

[phritz phantom <phritz-phantom@web.de>]

hello,
i just mixed up a 10% stock solution for sizing (used 0.2-0,3 gr/ 100ml 
5% gelatin)  and with the recent safety discussion, it's probably a good 
time to bump this question.
usually there are one or two chemists on the list. maybe can provide a 
final answer to the question below. and if there are any extra risks 
involved in handling the stuff (while taking the usual safety 
precautions like with every other darkroom chemicals: gloves, avoiding 
the use of powder/ breathing in, cleaning ... etc)
i assume that chrome alum has an unnecessary bad reputation (aka being 
as toxic as the dichromates). but i'd rather be safe than sorry.

thanks
phritz


phritz phantom schrieb:
> Judy Seigel schrieb:
> > As for chrome alum & company, it's my understanding that they are 
> > quite poisonous, and remain so, and not what you want to drop into 
> > the water table (along with all those hormones and pthylates).  
> > Whether glyoxal is poisonous or not, it does break down (as I 
> > understand these matters, but admit that I am not a chemist), and 
> > certainly by the time I dispose of it seems entirely attenuated.
> 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.
> effects on the water table could maybe be neglected, since most of it 
> should stay on the paper (within the gelatin size) anyway.
>
> but maybe someone more chemistry-literate than me could shed some 
> light on the whole thing.
>
> phritz