[Alt-photo] Antwort: Dichromate Poisoning
udo.schnitzbauer at uzh.ch
udo.schnitzbauer at uzh.ch
Tue Oct 24 06:10:04 UTC 2017
In the EU it´s now a a obsolete Question, because the sunset date for potassium dichromate was at 21. of September see for example http://www.gentrochema.nl/nl/sunset-date-potassium-sodium-dichromate/
Now the professional (in German: gewerblich) use and even to use it for a workshop* is forbidden.
*= see page 33 Number 12: "12. placing on the market: means supplying or making available, whether in return for payment or free of charge, to a third party. Import shall be deemed to be placing on the market;" http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:02006R1907-20140410&from=EN
Private use is not regulated according to REACH.....but you can not say the private use is allowed...a small but grave difference.
That was the juristic part....
[...]To argue that folks can get cancer from many sources is not very helpful
when discussing this subject.[...]
Sorry, I get not conform with that argument...
a) First the amounts of dichromate a very tiny and the (washing) solutions became very diluted.
E.g. for leather, which came in contact with the bare skin (24h/7d) the amount of Chromium VI compounds is limited to <3 mg/kg see http://www.chemsafetypro.com/Topics/Restriction/REACH_annex_xvii_Chromium_VI_compounds.html
Additionally according to Page 30 "6. Carcinogenic/mutagenic/toxic effects for reproduction" Table VI http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:31999L0045&from=en concentrations for substances with Carcinogenic/Mutagenic categories 1 and 2 have to be over 0.1% (calculated as dichromate) to be in this category.
There is a big dilution factor, if you wash the print....e.g. for a DIN A3 I use 4 ml of a saturated potassium dichromate solution. If you take a solubility of 13 g in 100 ml water (saturated solution) the 4 ml will contain 0.52 g potassium dichromate. Assumed 100% of this compound will wash out in the first washing solution, then you need more then 520 ml of liquid to be under the threshold of 0.1% for Carcinogenic/mutagenic effects.
b) With ascorbic acid solution there is a very easy way to decontaminate all stuff with is contaminated with Chromium VI see https://www.ncbi.nlm.nih.gov/pubmed/15488923 So contaminations, solid waste and washing solutions are not a big deal. That means the risks are manageable in my opinion.
c) Do you know that oak dust and more relevant for DIY people beech dust is in the same cancer category, both where confirmed as human carcinogens see https://hazmap.nlm.nih.gov/category-details?table=copytblagents&id=674 I think you will find many YouTube Videos where practitioners producing this kind of dust without gloves the necessary ventilation or protecting equipment. And I have my doubts, that people are change their clothes, if the walk up from basement hobby room.
d) and (okay not a real argument) a steak/sausage which is (strong) barbecued will have perhaps more CMR https://oshwiki.eu/wiki/Carcinogenic,_mutagenic,_reprotoxic_(CMR)_substances in it. Plus I am scout and we make fire in our tents https://en.wikipedia.org/wiki/Kohte so if we take it really serious, we have to forbid any fire in our tents....
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