Hello,
So I took a look at the product range of a "real" chemical supplier...
They have NaOH in such a variety that it blows my mind...
Apart from purity being expressed as a percentage, there are also differences depending on intended use of the product...e.g. specially for biochemistry they have NaOH that doesn't contain mercury or arsenic (+100 euros per kg)...
Even more confusing, sometimes 96% purity is approved "Pharmacopeia..." while there's also 98% purity that isn't "Phar, Eur."...
And what about "purified", "purum" and "puriss"? (I looked them up, which only slightly reduces confusion)
So, purity percentages do not tell the whole story and msds sheets rarely state which impurities are in a product...They just say, e.g., < 1% and that it's within acceptable limits, but is this 1% arsenic? butterfly pee? who knows?
With prices ranging from a few euros per kilo to over a hundred, I would gladly invite you to look at the page I mentioned and tell me, which do you think is best value for money/least health risk...
http://www.sigmaaldrich.com/catalog...048+219853269+219853286&mode=match partialmax
Don't forget to click "show all 18 results"
PLUR
PS Semi-conductor grade? Ever heard of that?