I think I've got this figured out in a way that should make sense to everyone:
The difference between "food" grade vs "technical" or "lab" grade has has to do with the way chemicals are processed and levels (or potential levels) of contaminants. An approved process ensures most of the potential harmful contents are removed, if any existed.
Any "food" or consumable grade, will be free of most dangerous toxins, impurities, and contaminants, while lab grade remains a relatively high purity, but may contain small amounts of impurities and/or contaminants.
In the case of final exit, such contaminants aren't anything to be concerned about, so lab, food, or any grade is valid and appropriate for our purposes.
I am posting this, in the hopes that it offers a better understanding of chemical composition and purity among the various grades. Please understand that this is only a rough guide, and you should use caution where possible, and avoid using...
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